Brain Stimulant

Neurobots: Robots Controlled by Brain Simulations

noreply@blogger.com (Mike) — Tue, 10 Nov 2009 05:09:58 PST

Researchers have been developing robots that are powered by better artificial brains. They have recently created a computer neural simulation consisting of 6,700 neurons with approximately 1.3 million synaptic connections. This technology builds on previous work in the field of neurorobotics. The robot they used for this experiment is shown on the left. It is equipped with a CCD video camera. The camera has IR sensors to avoid obstacles and an RF transmitter to process objects visually. The emulation attempts to model aspects of the mind that researchers believe to be important for information processing. The goal is to allow the robot to act in a manner similar to an actual animal. This gives insight into the functioning of the brain and how it encodes for behavior.

The scientists claim to have chosen three different neurotransmitters subsystems to model. These systems include dopamine, acetylcholine and serotonin. Dopaminergic, cholinergic and serotonergic cell bodies are found in the VTA, basal forebrain and raphe nucleus respectively. Some of these cells are located deep within the brain and they project their axons like a branching tree to numerous other regions. The synaptic junctions allow cross-talk between areas using these discrete neurotransmitters as messengers.

The VTA for instance (see picture on left), makes connections to places like the nucleus accumbens and prefrontal cortex. The neural facsimile they carried out emulates 100 neurons for each of these three cell body regions. Their simulation also contains brain cells devoted to processing images from the CCD camera. In addition, they have areas to encode for find/flee behavior and good/bad judgements (100 neurons for each).

So this is really an extremely simplified replica that is merely meant to represent some very basic ways that the researchers believe how the mind works. Obviously 6,700 neurons is much less complex than even a fly's brain. They ignored a considerable amount of neuronal function. So the behavioral output of this robotic device is definitely limited in scope compared to more complicated organisms.

The researchers appear to give an overly simplistic explanation for how specific neurotransmitter systems function. So I'm not necessarily convinced of the utility in labeling the 100 neuron subpopulations as "dopaminergic" or "serotonergic". Their brain is really only a crude simulacrum and assigning these labels may not be particularly relevant.

Dopamine appears to be important for “wanting”, that is, the motivation process in acquiring an object [13]. Dopamine, which is found throughout the central nervous system, is produced in the ventral tegmental area. A recent proposal ties the prediction error to wanting by suggesting that incentive salience is the expected future reward that maps actions to rewards [14].

There are a lot of nuances to dopamine's role in motivating an organisms to action and I'm not confident that the authors do it justice in their paper. Since this is done via computer, it does allow the scientists to do temporary lesions to see the resulting affect on robotic performances. They can basically turn off the functioning of specific neurotransmitter subsystems selectively. I'd be wary, though, of linking the behavioral changes that they witnessed to a real animal's dopaminergic system.

When CARL-1’s dopaminergic system was intact, it approached stimuli that were predictive of positive value, and ignored neutral stimuli. When CARL-1’s VTA was lesioned, the number of Find responses, which signify “wanting”, significantly decreased. Instead of approaching these positive-value stimuli, CARL-1 treated green objects as neutral stimuli.

They go on to talk about the other neuromodulatory systems and how adjusting them altered the functioning of the neurobot.

In our experiments with CARL-1, we showed that serotonergic neuromodulation arising from a simulated Raphe nucleus was needed to respond appropriately to threatening stimuli. When CARL-1’s serotonergic system was intact, it moved away from threatening stimuli, and ignored neutral stimuli.

The interpretations they make seem somewhat facile to me. However, I do think the interesting aspect of neurorobotics is that it allows the researchers to test an extraordinary range of different hypotheses. There is a lot of potential in scaling up the neuron count to enable a more extensive range of robot routines.

You can see some videos of this robot here. A recent paper on the topic is here (PDF). The researcher also gave a video presentation about it (see here, requires flash).

Neural Interface

noreply@blogger.com (Mike) — Sun, 25 Oct 2009 19:01:19 PDT

I found some more information about the HIVE project. A presentation was given November of last year discussing the potential of computer controlled brain stimulation (see PDF). The researchers definitely appear to have an eye towards some more futurist speculative uses of the technology.

10 Mapping our brains to computers (the singularity)
9 Jacking in (invasive interaction)
8 Non-invasive Brain 2 Machine + Machine 2 Brain interaction
7 Immersion (HMD/CAVE + haptics + ...) (also MR/AR) using natural senses

There is also a new article in AlphaGalileo about it as well. Here's an excerpt (translated from spanish);

One case of possible application that this (technology) poses to the future researcher Pablo de Olavide is in the treatment of some types of deafness. In this line, the device developed could be applied within a few years to develop a stimulus pattern that simulates human speech or sound, for people who can not hear through the ear, can get the information directly into your brain. "In these cases, the inner ear that fails, not the brain, so the device could be applied to stimulate the brain related to hearing," concludes the researcher.

Beaming sensory experiences into the brain could be helpful for those with certain disabilities. Scientists have also been utilizing brain research in order to facilitate the development of more engrossing and authentic virtual realities. Due to increases in GPU power, virtual environments will likely become more representative of actual real world circumstances as time goes forward. More theoretical technology might eventually enable computer generated sensations to be directly transmitted into the minds of normal people. I think some intriguing things could happen as this field matures. Being able to generate any sort of qualia on command via a digital program is basically the ultimate end point. Coupling that ability with more exact methods of fine tuning how the brain actually perceives qualia could usher in a transformative shift in consciousness.

Graphics Processing Unit (GPU) for Brain Research

noreply@blogger.com (Mike) — Sat, 10 Oct 2009 21:54:16 PDT

Graphics Processing Units (GPU) are commonly used to power video game software. However, they are also finding use for a more diverse array of scientific research as well. A GPU conference has recently taken place discussing some of the applications of this technology (see PDF 8.1 MB). Here are a few excerpts about the GPU brain projects. One deals with the connectome (circuit diagram).

Determining the detailed connections in brain circuits is a fundamental unsolved problem in neuroscience. Understanding this circuitry will enable brain scientists to confirm or refute existing models, develop new ones, and come closer to an understanding of how the brain works. Prof. Jeff Lichtman and Center for Brain Science (CBS) at Harvard launched the Connectome Project three years ago to determine the complete, detailed wiring diagrams of neural circuits from sequential high-resolution images of the central nervous system using electron microscopy (EM). These high-resolution, large-scale EM datasets pose very challenging computational problems for 3D segmentation and visualization in terms of developing suitable algorithms, coping with the ever-increasing data sizes, and maintaining interactive performance.

Visual recognition software is another area that this tech could speed up performance.

Nicolas Pinto is a second-year PhD Student in Computational Neuroscience at MIT. He is currently a member of the DiCarlo Lab and the Sinha Lab at MIT, and the Visual Neuroscience Group at Harvard. His research interests lie at the intersection of Brain and Computer Sciences. The overarching goal of his research is to dramatically accelerate the development of computational theories of how the visual cortex accomplishes object recognition. In addition to advancing our understanding of how the brain works by generating new experimentally testable hypotheses, this approach also holds great promise for the development of new artificial vision systems. A key innovation in his work is the ability to leverage the computational power of disruptive technologies like NVIDIA’s GPUs to provide new insights into this fundamental problem.

A Harvard researcher has recently talked about how these new methods will enable us to answer many of the big questions. From the Big Bang (and even before then) to the evolution of humans, computing power will truly help us understand almost any question imaginable. Better supercomputers may lead to complete and detailed simulations of living tissue. Researchers are developing multi-scale modeling from bio-molecules to organs (see PDF). With the help of these virtual models we will essentially be able to reprogram our own brain and body matter. Are we headed toward ageless bodies and superhappy minds? Only time will tell what new avenues this kind of processing power will open up.

See also GPU-Based Petascale Visual Computing for Analysis of Neural Circuitry (PDF).

Electron Microscope to Image Living Cells

noreply@blogger.com (Mike) — Tue, 06 Oct 2009 11:43:13 PDT

I have previously mentioned about increasing the resolving power of light based microscopes in order to better image living tissue. Electron microscopes have an even greater ability to view finer details. The only problem is that focused electron beams can easily damage living cells. Now scientists are using the properties of quantum mechanics in order to develop electron microscopy that would be able to create pictures of that type of tissue without destroying it. The researchers believe that eventually this will allow them to achieve a resolution of several nanometers. At this level of detail they could view individual molecules inside of cells. Obviously being able to view bio-molecular interactions within a neuron could have implications for improved understanding of their functioning. You can read more about this interesting advance in the press release.

Brain-Computer Interface and the Wireless Neurosociety

noreply@blogger.com (Mike) — Sun, 04 Oct 2009 19:54:32 PDT

Investigators have been creating superior wireless brain-computer interfaces (BCI). Being able to shed wires has the promise of enhancing the usability of these devices for those with disabilities. As time goes forward we may increasingly become a wireless neurosociety. This has the potential to irrevocably transform how we relate to others and interact with the environment around us. New tools may enhance our ability to manipulate the world and allow an unprecedented new means of communication with both computers and people.

Some scientists are additionally working on synthetic telepathy. This research basically entails capturing EEG brain readings that are the neural correlates of our inner monologue. These signals would then be translated by a computer into a voice synthesizer. This would allow a person to correspond with someone else without even opening their mouth. They would merely have to "think" about what they wanted to say and then that could be wirelessly beamed into an ear phone on another person. Theoretically new neuromodulation methods may also be used to artificially generate voices without the need for an ear phone. Brain implants (or perhaps non-invasive ultrasonic neurom odulation using an external device) that stimulated subpopulations of neurons associated with the perception of hearing might allow the creation of hallucinatory sounds. You would be able to perceive someone else talking clearly in your head. This could be useful in the military because this type of communication would generate no audible noise whatsoever. It could allow a two-way dialogue between soldiers using waves on the electromagnetic spectrum.

Researchers are also developing smart homes that could be controlled by brain com puter interfaces. Imagine being able to turn on your television, brighten lights or open doors solely with the power of your own mind. A thought reading helmet that could allow people to fly an airplane with their brain power is in the works as well. So it seems possible that a single sophisticated BCI may enable a person to exert control over their house, their car and communicate with others telepathically. Also, why type on a keyboard when you can just employ thoughts to disseminate information to your computer? All of your inner monologue could be continuously and automatically written down for you on a word software program.

Brain computer interfaces of the future may both decipher brain signals and manipulate them as well. Better deep brain stimulation implants are already finding increased utilization among people with specific disorders. Complex computer controlled brain stimulation may increasingly become the norm. However, there may be many issues that come up with regards to this new technology. These devices have the potential of being hacked by outsiders. Researchers have begun to consider the ramifications of these types of privacy issues for DBS implants. The fact that they now have wireless inputs means that they can be maliciously hijacked or spied upon by another person.

In a future society, some people may adopt more drastic types of implants for themselves. Being able to access information from the web and have it beamed directly into your head could be a tremendous boon for learning. The rate at which people acquire and manipulate data would increase at a tremendous rate. However, these types of direct connections to the net also bring up the same issues of privacy as with the less sophisticated neural gear. More complicated brain apparatuses might be susceptible to contracting some sort of virus that could radically alter the functioning of the appliance.

Imagine if you had a brain implant to improve memory and it stored a copious amount of information. A virus transferred by a wireless signal could possibly rewrite specific types of past recollections, thus altering everything about your previously remembered life history. Or perhaps a hacker or rogue AI program might adjust a person's behavior in a specific way. Maybe they could gain a top level control over someone else and turn them into some sort of botnet drone. Also other people might be able to gain direct access to the private introspection of another person. A wireless brain computer interface that recorded thoughts could potentially be spied upon, much like computers connected to the internet can be today by spyware. This may give a person or government insight into what someone was contemplating ahead of time. Certain countries might gravitate towards this possibility of better controlling or understanding their own citizens. Specific companies might also want the chance to broadcast advertisements wirelessly to a person's brain or gain access to what sorts of products the person would want to buy. If you can hear these messages within your head, how do you prevent your mind from being overrun by spam?

Some people may actually choose to allow others to eavesdrop on their own cognitive processes. This would be analogous to how many people use twitter to broadcast some of their succinct ruminations to whoever will listen. You could potentially selectively choose who you want to overhear your thoughts and block others from access. Will people in the future use neuromodulatory techniques to shed their inhibitions and allow a totally open society? A sousveillance where anyone can listen in on anyone else's internal monologue? Maybe a minority of people would even prefer to have outsiders control their behavior to a certain extent with targeted rewarding brain stimulation or another type of computer controlled mind manipulation.

Perhaps in the future we will also be able to send and receive nuanced emotions along with thoughts. A brain implant could acquire signals and then stimulate brain regions associated with certain feelings. This would be the next step in human evolution and would supercede regions of the mind currently involved in empathetic awareness. We would finally be able to truly feel others joy and pain directly instead of the roundabout way we currently do. I think there are a few other interesting question pertaining to this for future scientists to figure out. A main one being; how much of our consciousness or emotions can we transmit by using electromagnetic radiation?

Many of these things are now highly speculative. Brain-computer interfaces still have a long ways to go before they would have some of these capabilities. The adoption of any said technology may also depend on how easy or practical it is to use. The actual utilization of BCI's rests on the vagaries of future human desires and not what may theoretically be possible. However, there is definitely a lot of interest in improving this sort of technology. BCI's are already entering the market to enable people to play video games with their minds, for instance. So there are a number of interesting future scenarios that could crop up as time goes forward. A wireless neurosociety could potentially be a significant change from what people are currently accustomed to.

Transformative Brain Projects

noreply@blogger.com (Mike) — Thu, 24 Sep 2009 20:59:06 PDT

There are a couple new "transformative" brain projects that will begin soon. Neuroscience grants have been awarded to two people in order to further our understanding of how the mind functions. Here's an excerpt about the first project (connectome);

Mitra and colleagues, including Professor Harvey Karten of the University of California, San Diego, will use their “transformative” grant to produce the first brain-wide circuit diagram for the mouse, and using this as reference, attempt to determine alterations in the corresponding circuits of mouse models of neuropsychiatric disorders.

Below is an excerpt discussing the second project;

Josh Dubnau’s “transformative” project addresses an important gap in knowledge: about how this fundamental step in the conversion of genetic information -- its “translation” from RNA to protein -- is regulated in neurons, the ubiquitous cells of the brain whose dense web of connections underlie its capacity to perform sophisticated functions such as forming and storing memories.

There has also recently been talk about creating a complete connectome wiring diagram of the human brain. The NIH has aimed to do this within 5 years. A neuroscience blogger has shown skepticism about this. He thinks that the brain is far too complex and it will actually take much longer to get this diagram. I would partially disagree with his points. I believe it is important not to take an overly linear view of progress. Yes it seems like a daunting task. However, researchers are continuously creating better tools in order to acquire this type of data faster. I wouldn't argue that it will necessarily happen within 5 years, but I think the speed at which it occurs will be suprising.

Ray Kurzweil talks a lot about certain accelerating trends or (s-curves). Certain technologies don't progress in a linear rate, but much faster. In his book, Kurzweil gives an example;

"When the human-genome scan got under way in 1990 critics pointed out that given the speed with which the genome could then be scanned it would take thousands of years to finish the project. Yet the fifteen-year was completed slightly ahead of schedule, with a first draft in 2003.

Now the amount of people who have had their genome sequenced is probably going to increase at an exponential rate over the course of the next several years. It won't be long before everyone who wants to have their genome sequenced will be able to have it done. This has been happening because new tools have allowed for faster and cheaper sequencing of DNA. A main problem with Kurzweil is that he takes his accelerating trends analysis too far and tries to apply it to things where it doesn't work. Also these accelerating trends do end eventually, which Kurzweil doesn't spend enough time discussing. So while some of the points he makes are good, he is not necessarily the most reliable source. Overall, though, I think it is important to have a broader understanding of specific trends that exist in a variety of different fields. Many scientists/neuroscientists may have an overly narrow focus of what they study and it is difficult for any one person to keep abreast of developments in other fields. They may not be totally aware of scientific progress in unrelated disciplines, so they might underestimate what could be possible to do with technology and how fast it will occur.

Neurosystems for National Security

noreply@blogger.com (Mike) — Tue, 15 Sep 2009 18:40:31 PDT

I came across a research program at the Mind Research Network. It's called the Neurosystems for National Security and looks like it deals with the applications of brain technology towards improving the functioning of military personnel. Here's an excerpt;

MRN possesses the unique ability to utilize and combine functional imaging and brain scanning techniques (fMRI, MEG, EEG), computer modeling and simulation, cortical brain stimulation and genetics to investigate how the brain functions and how it can be made to function better for the safety, security, and reliability of our military and national security interests.

One potential benefit involves helping military and national security personnel make better decisions under stress. Biological changes occur in the brain and body in response to stress. These stress responses are intended to serve adaptive functions, but can also have a negative influence on cognition and behavior. One of our goals is to develop methods and techniques to leverage and modulate stress to optimize decision making. The ability to better modulate stress in times of crisis would be invaluable to both the foot soldier under fire and the general commander making critical national security decisions.

Many militaries have shown interest in brain research (see neurowarfare report). There are obviously a lot of ethical issues to this type of stuff. Should we really be pushing to use brain tools to improve the functioning of soldiers? There may be less benign things like using transcranial magnetic stimulation to reduce cognitive deficits associated with fatigue. Obviously if you could increase the sum total of cognitive or creative capacity of personnel it could have a huge effect on how well the military performs. There may be other radical stuff that might crop up in the next ten years that could be more ethically dubious.

Understanding the underpinnings of the stress response could enable soldiers who are better able to cope with being in battle. I've mentioned about using neurotechnology to amplify feelings of empathy. However, there is also the converse. New tools of neuromodulation might possibly selectively reduce these feelings temporarily to enable better soldiers who are less concerned about killing others. The insular cortex is a region of the mind that is involved with feelings of disgust. Perhaps you would alter activity in this area with certain drugs or brain manipulation techniques in order to regulate how disgusted a person felt from their actions. The intensity of other negative feelings like fear also might be lessened in severity. Beta blockers have shown promise in weakening the experience of bothersome traumatic fearful memories for instance. Maybe they could adjust activity in the anterior cingulate cortex in order to blunt feelings of pain as well. I think even minor alterations in soldiers brain functioning can be problematic from an ethical standpoint. It could be used by the government to make soldiers more likely to stay in the military or follow orders.

Brain technology has other applications to national security issues. Researchers have shown interest in using TMS/tDCS for detecting and altering deceptive behavior. Will these new tools allow a person to cooperate more with authorities? Perhaps they could be used to make a prisoner more likely to tell the truth. As these devices become more refined, it may become easier to alter a person's behavior in a specific way. Ultrasonic neuromodulation might potentially be used to change activity in reward related brain regions for positive reinforcement. There is also the possibility of using these methods to non-invasively modulate areas of the mind associated with pain for torture. I think we will have to have robust defenses against these sorts of abuses by people in authority.

Deaths from conflict have been on the decline over the past 50 years. So I'm somewhat optimistic that new tools will be beneficial for humanity as opposed to making things worse. Perhaps people in the future will choose to modify their behavior in order to edit out warlike tendencies. These technologies should theoretically enable people to enhance feelings of being one and at peace with others. Humanity may eventually change their temperament to such a radical extent that almost no conflicts will occur. This would be an extreme shift in how the world operates. Regardless of what actually happens, there are many interesting issues with regards to neurotechnology that our society may increasingly have to grapple with as time goes forward.

See Mind Research Network Sponsors Lecture on Neurosystems for National Security.

Neuron Imaging -Increasing Resolution Threefold

noreply@blogger.com (Mike) — Thu, 03 Sep 2009 16:59:21 PDT

Scientists are continuously refining tools to better delineate the details of the brain's cellular workings. One method of capturing extremely small aspects of brain cells is by using two-photon microscopy. This type of device can pick up minutiae that other scanners like magnetic resonance can't. Now researchers have increased the resolution of this imaging modality by threefold. They have combined stimulated emission depletion microscopy with the two-photon microscopy in order to gain this ability. This new method will enable them to see things like dendritic spines on neurons with more clarity than ever before. This will lead to a better understanding of how the connections between neurons function and change over time.

With conventional microscope lenses there is something called the "diffraction limit". This limit means that light can not be focused to less than half of its wavelength. However, researchers have found many news ways of circumventing this limit. Stimulated emission depletion (STED) microscopy is one of the first methods that overcame this limit. Researchers are continuing to better focus light so as to characterize smaller cellular features. Recently scientists have been able to focus light to 20 times smaller than its normal wavelength. In the future, the researchers hope to shrink light so it is comparable to the size of an electron's wavelength. An electron is an elementary particle that is much smaller than a single atom. Electron microscopes use beams of electrons for imaging purposes and have extremely high resolving power. The only problem is that they can't be used on live tissue, while light based microscopes can.

The researchers who have combined the 2-photon with the STED microscopy believe that they can already increase the resolution another threefold. This would be done by exactly timing the pulse of the depletion light. I think there will be a push to incorporate newer technologies to allow for even better resolving power in the future. This will lead to an improved understanding of how the brain functions at a sub-cellular level.

Neuromorphic AI Intelligent Text Recognition

noreply@blogger.com (Mike) — Wed, 02 Sep 2009 20:24:31 PDT

DARPA has shown interest in creating artificially intelligent text reading systems recently. The air force research laboratory has been developing neuromorphic programs that are inspired by how the brain functions. They are creating software that can fill in missing portions of sentences (PDF) based on the context of the previous words.

Modern pattern recognition technology can perform accurately at its job when images are complete and easily observable. However when there is only a partial text image, a computer's accuracy pales in comparison to the human brain. The human brain is able to fill in details based on contextual relationships of surrounding words. Researchers have now been able to get a computer to make up missing details in sentences. They have mimicked aspects of the mind that are involved with visual processing in order to carry out this task. With a sufficiently advanced system this might allow a computer to understand text or speech that is garbled or partially missing.

There are a variety of different "levels" of the mind that people are trying to emulate. I've mention about the Blue Brain project that is attempting to replicate neurons and synaptic connections in software. That project may become even more detailed than that as time goes forward. There are also somewhat less detailed simulations that may not go into that much depth and use more simplified neuron configurations. At another end, there are people who are attempting behavioral modeling. Instead of emulating brain cells/synapses, they are basically looking at the overall modularity of the brain and how certain areas function together in order to enable specific states of cognition to exist.

The air force has been focusing on simulations that are in between the more detailed Blue Brain and the less complicated behavioral models. This level of detail is at the cortical column level. They mention there are approximately 10^8 minicolumns in the neocortex. There are about 100 brain cells in each minicolumn and simulating connectivity between them is easier than trying to account for individual neuronal connections. Each of the 32 axons from a single minicolumn extend to 32 other minicolumns. So in the neocortex, they estimated that there are 10^11 connections at this level compared to 10^14 connections at the neuron scale. They are currently modeling brain areas like the lateral geniculate nucleus (LGN) and the primary visual cortex (V1). As time goes forward they may be able to make replicas of the functioning of other brain regions that are important for processing information.

They have investigated several different models. One is a bayesian model of invariant pattern recognition (see left picture). A representation of the visual cortex has already been developed using this bayesian framework. That brain region is important for processing what a person sees. This design can allow for a neuromorphic AI to be able to identify items.

The bayesian model has previously been tested using the images on the left. The model had an approximately 50% recognition rate of these 32 by 32 pixel arrays. The company Numenta Inc. has been developing this software independently of the military. Numenta has been continuously refining the technology for more sophisticated visual identification under more varied conditions.

The scientists also researched a network of attractors. They discuss the "Ersatz Brain Project". This project is an effort to replicate aspects of how the mind functions by using nested networks of fixed point attractors. This is more of an algorithmic method of mimicking parts of the brain. They specifically picked the brain state in a box (BSB) algorithm. They wanted to figure out how these models could scale to the full neocortical scale and copy the functioning of minicolumns.

They also investigated a spiking neuron columnar model. They performed a literature review on a variety of neuronal software imitations including Hodgkin/Huxley (HH), Morris-Lecar, and Izhikevich. They built software to emulate aggregate neuronal function with a higher level of detail than some of other parts of this project. Most of the other things involve duplicating brain modularity at a level above that of the neuron.

Finally, the paper discusses a confabulation program that has been developed. Confabulation means that the program can make up completions to partially blank sentences. The researchers trained the sentence completion program by feeding it a lot of text. The intelligent text recognition would perform differently depending on what author it had read. For instance when it was trained using only material written by Shakespeare, the confabulated (made up) sentences resembled ones produced by that author. The "Original" sentence is shown below. That is followed by the "Starter" words "Go to" that are fed to the computer. The "Completion" is the made up sentence that is based on the two starter words.

Original: “Go to the forge with it then shape it I would not have things cool.”

Starter: “Go to”

Completion: “Go to me at your convenient leisure and you shall know how I speed and the conclusion shall be “

The scientists have combined a few of these discrete models into one cohesive program. They have developed a hybrid BSB/neuronal model and a hybrid BSB/confabulation model. They have also investigated about the potential of scaling up the hierarchical bayesian model and the fixed point attractor network models to an entire brain.

It appears that they are getting some interesting results thus far. The hybrid BSB/confabulation model was able to recognize character fonts using a 16 by 16 pixel array. They fed the program sentences with characters missing (see picture left). When 20% of the characters/words were missing, the program was 99% perfect in identifying the correct missing letters. This success rate was due to the program being trained on reading material.

I've been skeptical myself of being able to copy the functioning of the mind in software. However a lot of this work is more inspired by how the brain works, instead of imitating it exactly. I think this research on neuromorphic AI looks promising. If scientists can meld aspects of what the human brain does best with what computers do best, I think we will see a lot of interesting things come out of it.

Neuromorphic Architectures Beyond Moore's Law

noreply@blogger.com (Mike) — Sat, 22 Aug 2009 22:18:32 PDT

Neuromorphic engineering seeks to emulate how the brain functions via computer chips and/or software in order to better carry out specific functions. The brain really is an amazing organ than can do certain tasks much better than any computer. A lot of the research being done in this field is building models that are inspired by how the brain functions. The military, for instance, is keen on developing this technology for better AI learning/recognition of reading material among numerous other potentially beneficial tasks.

Moore's law itself doesn't appear to be ending soon, at least when it comes to increasing the amount of transistors. However even with this boost in computer chip hardware, certain software measures are just not improving at the same rate. Neuromorphic engineering has the potential to exploit how the brain functions in order to increase the speed at which specific tasks are performed (such as visual recognition). Here's a short abstract describing the potential (PDF).

Within this period traditional scaling of transistors in CMOS technology, will have reached its physical limits. However, advances in nanoscale structures such as carbon nanotubes and semiconducting wires have the potential to add new functionality by augmenting traditional processing in nano-CMOS technologies. We will move slowly but steadily towards an era where breakthroughs in the field, will not be driven only by research aimed at exploiting and managing the exponential rate of digital transistor density in CMOS technology (Moore’s Law). Research and development in the field will strive towards benefits from methodologies that allow advances in the structural complexity of micro-systems.

From an architectural viewpoint, we take inspiration from Nature. Biological information processing systems employ dynamic matter and learning at all levels in an amazing network of complex structures of different scales, from the nano to the micro and macro. Both biological brains and sensory organs operate at performance levels set by fundamental physical limits, under severe constraints of size, weight and energy resources and they are indeed engineering marvels of heterogeneous integration and structural complexity across different physical scales,

Another abstract discuss the potential (PDF) of using memristors to model neurons.

Memristive nanodevices may fill the role of an electronic analog of biological synapses: they are essentially analog memories that can be switched between extreme states in 20 nanoseconds or less, yet maintain their state for years when power is removed. They can also be manufactured at biological scale densities (more than 1010 devices per cm2) and integrated with conventional CMOS.

A workshop just recently took place to discuss these novel computing advancements.

Hive Project, Computer-Controlled Brain Stimulation

noreply@blogger.com (Mike) — Mon, 17 Aug 2009 19:04:25 PDT

I came across another european project that seeks better brain stimulation capabilities. It's called the "hyper interaction viability experiments" or HIVE for short. The terms in the acronym sound like gibberish, but the project itself looks legitimate.

Our goal is to research stimulation paradigms to design, develop and test a new generation of more powerful and controllable non-invasive brain stimulation technologies. HIVE will develop improved electrical current distribution and multi-scale neuron-current interaction models and carry out stimulation experiments using tDCS, TMS, EEG and fMRI in different scenarios, and based on these develop multisite transcranial current stimulation technologies implementing real time EEG monitoring and feedback.

Here are a few of the problems with current technology that they mention;

Poor understanding of the effects of stimulation at the neuron and neuronal ensemble level: the project will investigate the biophysics of stimulation at the theoretical, computational and experimental level––both in humans and animals.
Unfocused, un-precise stimulation technologies: an important objective of this project is to develop new multisite electromagnetic non-invasive stimulation paradigms to implement more controllable and effective stimulation technologies and applications. The project will develop a Multisite transcranial Current Stimulation and monitoring prototype (MtCS) for finer control of current flows in the brain and subsequently explore related applications.
Limited animal and human stimulation experimental work: the project will explore new stimulation paradigms to communicate and interact with neural ensembles and the human brain.

Brain stimulation devices that are controlled by computers already exist to a certain extent. This work will continue that trend. The next step is making improved brain-computer interfaces that directly manipulate the brain. Perhaps this could be done with small enough ultrasound transducers implanted on top of the head to selectively stimulate discrete brain regions anywhere. Maybe you would even use a brain computer interface that learns over time to perfect the interaction with the mind and couple it with some sort of brain reading device.

What would our consciousness be like if we were to interface with a computer? I think it could potentially be radically different depending on how refined the technology was. A computer would be able to coordinate activity in multiple brain regions at a time. Any perceptual qualia could be modulated, possibly by upregulating or downregulating brain activity in specific areas. This type of interface might entail altering the salience of food taste, improving visual working memory capacity, increasing empathic understanding or even enhancing spiritual awareness. As we move toward programmable brain matter, the future of consciousness will be truly awesome.

Free Will and the Brain

noreply@blogger.com (Mike) — Mon, 07 Sep 2009 10:09:32 PDT

Free will is the idea that we are the driver of our own actions. We feel that we are in control of what we do. Our behavior does not seem like it is happening to us in a deterministic fashion. We feel that we are not passively watching the "movie of life", but can will our own actions to almost whatever we so desire. Is the position that we actually have something analogous to free will tenable, given what science currently tells us? Do we merely have the perception of free will? Also can future neuromodulation techniques potentially enhance our perception of being in control of our own lives?

There is a lot of confusion about free will and quantum mechanics. All particles in your brain, your body and any external non-conscious object all follow the same probabilistic laws. So you can't claim that the brain has some special laws of physics that are separate from anything else. Invoking quantum mechanics to explain "free will" is sort of like arguing that a slot machine has "free will" because it gives out prizes based on probability. All that quantum mechanics means is that there are things that happen indeterministically at the atomic/subatomic level and we can't predict their outcome ahead of time (measuring the spin of an electron for instance). This applies to all matter equally. Consciousness has absolutely nothing to do with these sorts of outcomes either. Most quantum effects are at such a low level, that they have basically no effect on the overall mechanistic action of how neurons function. Anyways, a widely accepted interpretation of quantum mechanics hypothesizes that the the probabilistic outcomes we view are merely a subset of outcomes in a larger multiverse where all possibilities are realized. The many world's interpretation IS a deterministic theory. The only reason we see probabilistic outcomes is that we can't interact with other branches of the universal wave function. The universal wave function evolves in a deterministic fashion.

I think there is an important thought experiment about free will and consciousness. What if your consciousness was exactly the same as it is now, but was lacking one crucial detail? You would wake up, eat, talk to people, go to work, go to sleep etc. The exact same thoughts would run through your head as they do now. However, with this consciousness you would feel like your body just did things without you exerting any control over it. You wouldn't feel like you were consciously selecting your thoughts, they would just happen. This is opposed to our current mental state of feeling like we are the driver of our thoughts and actions. It would basically be like you were passively watching a movie of your own life. Why don't we experience this? My guess is that over the course of millions of years, evolution has increasingly coupled a feeling of being the driver of our actions with conscious experience. It may merely have been adaptive to have this feeling of control over ourselves.

There is evidence from neuroscience that our brain can create a "narrative" and makes us think we did something by willed choice of action when in reality we did not. Researchers have used transcranial magnetic stimulation targeted to frontal brain regions on people to see its resultant effect on decision making. Normally people who are right-handed would choose to move their right hand 60% of the time. However, when the right hemisphere of their brain is stimulated with TMS they would choose to move their left hand 80% of the time. Even with this obvious manipulation of behavior, people's perception of free will remained intact. They still erroneously believed that they had chosen that behavior by their own cognizance. That would indicate that there may be a mechanism in the brain that essentially confabulates about whether we freely made a specific choice.

There are a variety of brain disorders where free will seemingly begins to vanish. In obsessive compulsive disorder, people may repeat specific behaviors again and again. They don't really want to do these behaviors and find them extremely distressing. Schizophrenic patients may sometimes have "thought insertions". They may have ideas in their head that they think are being put into their brain by outside sources. So these are in essence analogous to the thought experiment above. Certain thoughts or behaviors that they have feel like they are not being selected for by themselves. There is also alien hand syndrome where the hand moves on its own and it doesn't feel like the person has any control it. As opposed to these being instances where people lose their free will, it's possible that people merely lose the perception of free will in these disorders.

In some sense you could argue that a lack of free will is already embedded into how we consciously perceive the world around us. We can't currently control (at least not very well) how we perceive the world. Our perception of the world is based on a built up consciousness constructed by natural selection over the course of millions of years (selfish gene). Our conscious view of "objective reality" is merely an artificial representation of reality. People sometimes tend to forget how much of our consciousness is highly variable from one individual to the next. On earth you have billions of people and each is living in their own "virtual world" that is tainted by their unique brain chemistry. Each person may experience different perceptual qualia of varying magnitudes of intensity. An example being taste pleasure. Sugar tastes sweet because experiencing this sensory qualia was adaptive for our ancestors. Natural selection has the ability to fine tune perceptual qualia over time and environmental circumstances can change. Now sugar is available in abundance for many people. If finding sugar sweet suddenly became maladaptive, then experiencing sweetness might eventually be weeded out of the gene pool. Maybe people who don't find sugar that sweet have more children on average now. It is possible that our descendants may find sugar neutral or even repugnant in flavor.

Many males may find younger women more beautiful on average because those females have a higher fertility than older women. Finding younger women more attractive increases the probability that a male will pass on his genes and have more descendants. Evolution constructs a brain that places positive or negative value on external objects (prettiness, ugliness, tastiness etc.) Maybe I find scenes of nature beautiful because my ancestors were the ones who explored new territory. Perhaps people in the past who didn't find nature beautiful never went on to spread their genes to new worlds. Obviously conscious experience is complicated and is dependent on many factors other than genetics (such as environment, upbringing). However our consciousness is what drives our behavior. Our whole brain reward system is specifically set up to get us to do behaviors which are good for our genes (eating, mating, having children etc.). If you find sugar sweet, you bet you're going to be eating a lot more of it. Stimulating certain brain regions can make people desire to move their appendages. So evidence like this shows that we are basically slaves to our own brain chemistry and the consciousness it creates. A lot of our wants and desires are reducible to how our brain functions.

What about the future of free will? We know that consciousness drives behavior. New neuromodulation techniques will increasingly become available so as to allow us to shape our consciousness to anything we desire. You could identify the neural correlates of beauty in the brain and then amplify them, applying them to any external object. You could theoretically make the average 90 year old woman appear more stunningly attractive to a male than any young female supermodel. The only reason that this isn't the norm now is because it would have been maladaptive in the past. By understanding how consciousness motivates behavior you can possibly predict how a specific change in brain function will alter the way you act. So in some sense this is improving free will, as we are uncoupling our consciousness from our evolutionary past. We can create a consciousness to be whatever we want.

Will it be possible to find the neural correlates of the perception of "free will" and then amplify that perceptual state? Using advanced brain imaging techniques and subsequent neuromodulation we may theoretically be able to artificially enhance our feeling of being in control and the driver of our own actions. An absolute and all consuming feeling of being able to manipulate the environment can be embedded in the texture of every day experience. Perhaps this could even ludicrously be extended to having a feeling of being one with the universe and that you have absolute power to exert control over all things outside oneself. Even distant objects that you do not have direct contact with. This would be the ultimate feeling of "free will". You would feel like you were the driver of every action you observe in your perceptual consciousness. This would be an almost psychotic perception of control exertion.

In the past, your consciousness never evolved the capacity to attribute free will to objects that are not directly connected or manipulated by yourself. I would imagine it could be possible to trick your brain into thinking that you control every object in your perceptual consciousness by willed action. I'm not necessary talking about making a person believe they have psychokinetic powers. I'm talking about tricking your brain into creating a narrative that explains all events happening in your conscious perception as being attributable to your own exertion. Just as the people's brains in that transcranial stimulation experiment made them think that they chose to move that specific hand after the fact. It could be akin to some sort of confabulation that your brain would make to explain away things no matter how absurd they might seem. While all of this is highly speculative, I definitely think that better understanding of the brain and new brain stimulation techniques could be used to enhance feelings of being in control of our own lives. For many people this may be a welcome change in consciousness.

Cyborg Insects

noreply@blogger.com (Mike) — Tue, 21 Jul 2009 18:48:19 PDT

I came across something related to my previous post about a virtual fly brain computer model. The military has been developing better cyborg insects. Instead of trying to mimic the functioning of an insect by using robotic technology, they are basically co-opting what has already evolved over the course of millions of years. They are using actual bugs fitted with some type of cyborg implants. It seems obvious that a virtual brain of an insect could help this process along. Imagine melding the latest developments in computing power, brain research and nanotechnology to create more sophisticated insect drones. This science fiction idea has been around for quite some time, but reality may be finally catching up to fiction.

There has been a lot of speculation about replicating nanotechnology machines. This technology may be much further away coming to fruition, if they are possible in the way futurist envision them. However nature has already honed insects to be excellent self-replicating machines. So can you improve upon nature and make them even better replicators? Perhaps cyborg insects or insects who had their genetic source code radically modified with the help of a virtual computer model could enable the creation of super insects. Insects can be extremely annoying already. However, how about dealing with these enhanced insects? There could be a rapid shift in the evolution of the earth's ecosystem.

From a societal standpoint, this brings up a lot of ethical issues. It is becoming easier and easier to snoop in on other people. Our privacy is increasingly being eroded away and it looks like little can be done about it. What if you had to worry about whether the tiny insects in your house were actually surreptitiously taking photographs or movies of you? It might be relatively easy to fit an insect with a miniature spy cam. Should society just allow everyone to spy on everyone else? Sort of like a grand sousveillance. Imagine if all of the video from these spy drones could be wirelessly uploaded to the internet and kept on record forever. Most of your life could be on file and known by everyone and anyone who so desired to know it. This would definitely alter the way that people behave.

Also could you create insects that infected their host with some sort of parasite so as to alter the subject's behavior? Toxoplasma gondii is a parasitic protozoa that infects rats and makes them fearless in the face of cats. It alters the rats own brain chemistry, specifically to get it killed so that the parasite can further reproduce in the stomach of a cat. Obviously you might not want to make your enemy fearless, but infecting them with something that could desirably altered their behavior might be a plus. Maybe you could make a parasitical organism that toned down religious ferver in an extremist. One would hope that if someone with malicious intent were to do something of this nature that at the very least they would create a more positive consciousness in their enemy, as opposed to making them overcome with fear, anxiety or paranoia. A totalitarian negative utilitarian could attempt to engineer more happy minds in other people, albeit against their will. Perhaps you could make your enemies fall deeply in love with the rest of humanity so they would never want to hurt anyone ever again.

Some of these are highly speculative scenarios, but science tends to progress fairly rapidly in a few of these domains. So some of these issues may happen sooner than some people realize. Cyborg insects appear to be a reality to a certain extent already. So the future will likely see insects that are even more capable and sophisticated at doing specific tasks than what currently exists.

Cognitive Enhancement Debate

noreply@blogger.com (Mike) — Wed, 01 Jul 2009 16:21:54 PDT

Zack Lynch posted a video debate about cognitive enhancement on his blog. I just wanted to mention a few of my thoughts on this topic. I think currently a lot of the so called memory improving drugs leave a lot to be desired. I would say that the average person probably would not want to take a drug which caused increased activation of acetylcholine receptors. Dopamine reputake inhibitors can improve concentration and certain aspects of cognition, but they are also not ideal drugs in any way. They can be addictive and may also increase other unwanted traits in the user like stereotypical behaviors. Both transcranial direct current stimulation and transcranial magnetic stimulation have also been used to enhance the capacity of working memory. It's hard to say how relevant this would be for most people, though. Transcranial magnetic stimulation is fairly expensive and might require ongoing use to have any benefit from it. Transcranial direct current stimulation (tDCS) is cheaper and could theoretically be done at home using a portable type device. However tDCS also has less selectivity in its ability to target brain regions, so it is unclear how useful it would be for the average person. Deep brain stimulation seems far too extreme for most people to gain any benefit from.

I think a major problem is how do you define "cognitive enhancement"? The brain is so interconnected that it is hard to affect one cognitive process without tangentially affecting another. You may be able to temporarily improve working memory, but how do you know this doesn't cause worsening on some other type of cognition? Even if you have a good knowledge of the brain, you may not be able to understand all the complex relationships between different brain regions and how they enable specific states of cognition to exist. It could be hard to manipulate things to a desired set point of functioning.

Another problem is that any single drug has the potential to induce massive changes throughout the brain. Even drugs that are rationally designed to be selective are not really all that selective. An SSRI is selective in the sense that it only affects a single transporter (serotonin). However it is non-selective in the sense that there are many serotonin receptors and an SSRI increases serotonin in the synapse thus causing increased activation of all these receptors. Also since you can't disentangle one neurotransmitter system from all the rest, a drug is basically going to change multiple different neurotransmitter systems at the same time. Serotonin regulates the firing of dopaminergic neurons in the ventral tegmental area for instance. SSRI's are of course, not considered cognitive enhancing drugs. However this rule applies to any pharmaceutical drugs that are in the pipeline for "cognitive enhancement".

Even if you use something like transcranial magnetic stimulation to target "selectively" the dorsolateral prefrontal cortex, this area has connections to many other brain regions. Activity in these other areas can be altered even if it is unintended. Also TMS either excites the neurons in the underlying tissue or inhibits their firing. However some neurons being activated may be excitatory, while some neurons being excited may be inhibitory. So your really getting a huge mix of effects that may difficult to really sort out. Some neurons being excited may cause other neurons to decrease their firing rate.

I kind of think that many people looking for cognitive enhancement may be somewhat disappointed currently. There are plenty of more far out technologies like neuromorphic brain implants or brain computer interfaces that could amp up cognitive processes dramatically. However these may be further away. I think most things for enhancing memory or attention now are very blunt tools with undesirable properties and may be of limited value for many.

Virtual Fly Brain Computer Model

noreply@blogger.com (Mike) — Thu, 11 Jun 2009 12:22:37 PDT

Most people think about ways that they can get rid of insects. However, some scientists are actually considering what it would take to create artificial insects with virtual brain's. Researchers are now planning to create a computer simulation of a fly's brain (drosophila). Could this virtual fly brain enable military mad scientists to fine tune a bug's functioning? Perhaps you could recalibrate a bug's pleasure circuitry so it would find enjoyment in injecting deadly poison into enemy combatants. Or maybe this might allow the development of increasingly complex forms of insect behavior like swarming or intelligence gathering by precisely altering the bug's neural wetware (with the help of the model).

I've previously mentioned about some attempts to construct computer simulations of the human brain (see computer brain simulation and blue brain). A human brain model in silico is quite a monumental task to undertake and may not come to fruition for quite some time. I've also noted before about my skepticism in the ability to model consciousness without the physics of our world. The human brain contains about 10^12 brain cells, 10^15 synapses and an exceedingly diverse array of synaptic proteins. At the very least, all of these are likely important for the overall functioning of the mind. Comparatively, the fly nervous system only has about 100,000 neurons. So it's surprising that modeling a bug's brain wasn't an obvious first choice. It's just so much simpler to do than a human brain. I personally find it highly probable that all insects have a simplified form of consciousness.

For the virtual drosophila brain, the researchers are proposing that sensory inputs and outputs could be added into the model. These senses include basically everything that would be part of a bugs perceptual experience (tactile, auditory, visual, gustatory, olfactory, even magnetosensory). An insect likely has a unitary consciousness that coalesces all sensations into one overall perception with discrete qualia. A more voluminous brain can probably enable a more complex conscious awareness. So we can assume that simpler organisms likely have a less complicated representation of objective reality. Specific "objects" may appear much cruder and far different to a fly than they would to a human being. An insect's consciousness only has to represent reality enough to drive behavior in a specific way.

A major stumbling block to modeling an insect brain is being able to scan all the relevant brain cell configurations and synaptic connections. They could visualize aspects of brain functioning using electron microscopy. However this would generate 26 terabytes of information and would require a huge amount of man hours to prepare the material. Recently faster methods have been developed to procure and analyze the data. This may not remain a constraint forever in the future.

The researchers mention that there are about 2000 to 3000 genes linked to human inherited diseases that are conserved between a fly and human. So being able to better understand the mind of a this insect has implications for human brain disorders as well. However, there are also considerable differences between the two, such as the fact that drosophila brain cell axons are not myelinated. This lack of myelination means that neural signaling may happen less quickly than in mammalian brains. Also drosophila doesn't really have the same blood flow and cardiovascular system as mammalian brains do. So oxygen reaches the neurons in a fly in a completely different way (not through red blood cells).

The researchers conceptualize the model as being used to predict the subsequent behavioral fly output when a specific neuronal adjustment is undertaken. Like how would a fly act if scientists were to upregulate a single receptor protein in a key brain region by genetic engineering? In the past, researchers have been constantly modifying the genetic source code of drosophila. However, this virtual model could potentially exponentially increase the understanding of how neural changes encode for behavior. It might become much easier to remodel a bug's functioning to essentially do whatever a scientist wanted it to do. They would basically be using a control type theory for the virtual model that could continuously be adjusted in order to refine it. So the virtual model may not necessarily have to be conscious in order to successfully predict the behavioral output of any brain change.

If successful, a virtual bug model could allow the creation of increasingly bizarre insect minds that have never before been seen in nature. Better modeling and understanding of these simulations might allow scientists to fashion more computationally efficient insect brains, for instance. Maybe they could increase the amount of proteins in the synapses or add myelination to the neurons so as to overclock the fly's brain. They might be able to tell ahead of time the subsequent effect on behavior. Studying the nature of consciousness would also be a fascinating aspect to this. Could you create a bug that was blissed out and euphoric? Darwinian natural selection usually precludes these extreme states of well being, but that doesn't mean you can't engineer them in an insect. Just imagine all the unique modes of consciousness that are possible by tinkering with a bug's genetic code. Perhaps these models could go a long way in helping to understand consciousness in an objective fashion and how it relates to behavior.

Obviously this project could take quite some time, but I think it could potentially happen faster than making a human brain computer model. The first models would probably be simplified, but could increase in detail over time. The fact that researchers can genetically engineer and breed flies so quickly also means that it would be much easier to test out the model to see if it was predicting behavior. A lot of interesting things could become possible in the future as this field matures.

Armstrong, J., & van Hemert, J. (2009). Towards a virtual fly brain Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 367 (1896), 2387-2397 DOI: 10.1098/rsta.2008.0308

Magnifying Taste Pleasure by Neuromodulation

noreply@blogger.com (Mike) — Fri, 31 Jul 2009 16:07:38 PDT

I've been thinking about the nature of consciousness. This post will be a speculative and somewhat unrealistic "what if?" propositon about extreme qualia. Qualia is philosophical speak for "what it's likeness" (redness, tastiness, pain, etc.). Qualia is essentially how we consciously perceive aspects of the objective world through our senses. Will people be able to increase their capacity to enjoy foods? Will future neuromodulation techniques allow us to make the food we consume amazingly delicious? One current way of making a delectable meal is to slave hours over the stove using only the finest ingredients available. A future method to create a sumptuous mouth-watering taste experience may be done by using advanced brain manipulation techniques so as to actually enhance the mind's ability to assess pleasant foods. We can also possibly ensure that we are able to enjoy a diverse and unparalleled array of textures that exceed our current palate by several orders of magnitude.

Using neuro alteration, one can potentially make any food taste exceedingly wonderful. These types of of extreme piquant qualia have previously been inaccessible to any conscious mind in the history of the earth. Darwinian natural selection precludes their existence. However using neuroengineering, the taste of the ambrosial food of the divine can be summoned up on command. Perhaps this marvelous savory taste perception can be applied to healthier foods so we don't become excessive unhealthy gourmands. Or maybe these sensations could be turned on without the actual consumption of food. A brain chip might enable us to elicit these feelings whenever a person so desired. The chip could be specifically designed to artificially induce extreme taste qualia that would be uncoupled from any sort of eating.

Scientists are increasingly unraveling the neural correlates of taste hedonics. Kent Berridge has done extensive research in determining the location of specific "hedonic hotspots" that are involved in sensory taste pleasure. The brain regions related to experiencing these phenomenon include the ventral pallidum and also the nucleus accumbens. Amping up mu-opioid and endocannabinoid receptor activation in these discrete brain areas has the capacity to make certain food much more appetizing. A lot of this research has been done on rats by observing the changes in their facial expressions when neurochemicals in specific regions are altered. They can actually tell that the rat is enjoying sweet food more by the way it licks its lips. I think for most people it should not be too surprising that drugs which affect the opioid or cannibinoid neurotransmitter systems have the ability to make food subjectively more palatable. People often use alcohol to increase food enjoyment and alcohol perturbs the opioid system. A pizza that normally might taste like fodder could taste amazing after taking a large amount of alcohol. Marijuana (a cannabinoid) tends to give people the munchies as does heroin (an opioid). These neurochemicals are dissociable from dopamine, which does not seem to increase "liking" of food. In the future, more sophisticated techniques may become available for precise taste perception alteration.

Taste hedonics has been an important evolutionary driver of behavior for an organism. On one level, the tongue has evolved the capacity to detect certain molecular configurations of matter. On another level the brain has evolved a way to assign value to specific types of matter that are placed in the mouth. Matter that has an overall beneficial affect on the functioning of an organism often subjectively tastes really good. Conversely, matter that is harmful to the organism may taste awful and is in general quite noxious. Sugar tastes sweet because this specific sensory qualia was adaptive, evolutionary wise, for our ancestors. Organisms that found sugar to taste sweet did better than organisms that found sugar to be repugnant or neutral in flavor.

Currently, there has been a substantial environmental shift for humans. The advent of the supermarket has made a plethora of sugary foodstuff items available in plenitude. This has happened while the neural signatures for assessing sweets in the brain has remained largely the same. This may not be the case forever, though. In the present/future, evolution will likely select against finding sugary foods as being too sweet. A person who consumes a lot of sugar probably ends up overweight and thus reduces their reproductive potential overall. They may be less likely to have children. Rational brain engineering may allow us to overcome this negative effect, however.

We can assume that different animals may experience somewhat similar forms of taste hedonics. All mammals may enjoy foods with high glucose concentrations for instance. However a specific item that tastes scrumptious to one organism does not necessarily taste good in the same way to another organism. On the earth there are trillions of conscious minds and each likely experiences some sort of perceptual taste hedonics. Consuming food is integral to the life of almost any animal. Each conscious brain is the result of a unique aggregation of atoms that encode for a particular perceptual experience. Will we be able to categorize and actually understand these perceptual qualia of all organisms on the tree of life and their neural correlates? Once we have correlated these neural signatures, then can we possibly replicate it in our own brain chemistry and amplify those textures of experience to dizzying heights?

Why don't these extreme qualia currently exist? Suppose you were to saturate a single macroscopic item (example sugar) with extreme positive value. Imagine if a neural pathway evolved to find this specific foodstuff item exceedingly delicious. This item would taste so good that you could never get enough of it. This foodstuff would in essence become an all consuming driver of behavior. A single item would become a veritable black hole abyss by which an individual's behavior would be inescapably and indefinitely drawn toward. In the evolutionary fitness landscape this would be maladaptive. Evolution normally wants an organism to have a diversity of behavior (like eating a variety of food items that serve separate biological purposes). Extreme qualia drives an organisms behavior toward that one item and would potentially cause them to ignore other perhaps equally important items in the environment. Also sometimes evolution just does the least amount of work necessary to motivate an animal. Why make something extremely tasty when you can get the same behavioral output by making it just taste pretty good. Evolution often tends to spurn excess.

Can you engineer extreme qualia while at the same time maintaining a diversity of behavior? Also, can we disentangle these qualia from the actual act of consuming food? How do you ensure that a person's behavior does not get stuck in a suboptimal rut? Perhaps these future extreme qualia will serve no functional purpose. Maybe they will merely be based on whatever arbitrary whim a person has. Like activating and deactivating a brain chip whenever they want to experience a specific sensation. I think the future will become extremely interesting if we can potentially affect discrete qualia and shape them to whatever we desire. Neuroengineering may eventually allow extreme qualia that are currently closed off to current brain wetware.

LILFU and the Brain

noreply@blogger.com (Mike) — Thu, 04 Jun 2009 15:22:04 PDT

Technology Review has a new article about brain stimulation using ultrasound. Basically it talks about some of the stuff that I have previously mentioned, but there are a few new things about more recent experiments done. Here is an excerpt;

"With ultrasound, we have a much better spatial focus than [with] DBS," says Tyler. "And unlike TMS, we can get anywhere in the brain." Ultrasound--consisting of sound waves with a frequency above 20 kilohertz--has been used for decades in medicine to image muscle, organs, and fetuses.

Recently, ultrasound has been shown to alter the morphology of neurons. So it should be interesting to see what sort of manipulations may become possible in the future. Ultrasound could potentially be used to fine tune several aspects of brain cell functioning.

Deep brain stimulation has been shown to spark new neuron growth in key brain regions. Research has shown that these neurons are functional. So I think researchers may find ways of using non-invasive brain stimulation (deep TMS or possibly ultrasound) to do the same thing.

Neuro Brain Thermodynamics

noreply@blogger.com (Mike) — Mon, 01 Jun 2009 19:25:23 PDT

The brain is a metabolically expensive organ that uses quite a bit of energy. It's no surprise that it also generates a decent amount of heat during this energy usage process. A new paper has come out that poses and answers the question as to whether there is a thermodynamic limit to brain size (evolutionary wise). The author is basically asking how big can a brain get before it becomes too hot to function properly? What sort of constraints does evolution have in constructing a bigger brain, given the laws of our universe? The answer he gives, in short, is that there is plenty of room thermodynamically to evolve a larger brain.

The paper first discusses the main cause of the generation of heat in the brain. The Na+/K+ pump helps to maintain the cell membrane potential of every neuron. The pump allows a neuron to have a high concentration of K+ ions and a low concentration of Na+ ions inside of it. The protein molecule pump hydrolyzes an ATP molecule, using that energy to move 3 Na+ ions out of the neuron and 2 K+ ions into the neuron. These ions are integral to the electrochemical signaling of a brain cell and their concentrations change in response to the propagation of an action potential down a neural axon. So the pump is necessary to restore ion balance to a neuron after it fires.

The whole paper is a bit mathematically intense. The author's intent is to figure out how much energy an aggregate number of neurons use, mostly focusing on the Na+K+ pump and neglecting brain glucose utilization. The author goes on to discuss how the brain regulates the heat generated from all of this work that occurs and the specific constraints on neural processes. Some heat radiates from the scalp. Cerebral blood flow (cbf) is another method that the brain uses to cool itself. Up the evolutionary mammalian line, cbf essentially scales with brain volume. So I think that means the amount of blood vessels are basically proportional in creatures that have varying brain sizes. Due to this scaling up, there is apparently a small decrease in the rate of blood flow as you go from simpler to more complex organisms (mouse to human for example), because of more surface area coverage.

Increasing cbf in a specific deep brain region can cause a resultant decrease in brain temperature there. According to the author mammal's brains can sustain a temperature upwards of 42 Celsius without becoming damaged. Though, the optimum temperature may be much lower than that. Certain drugs have the ability to increase the brain's temperature in part by vasoconstriction. Cerebral blood flow only acts as a coolant inside deeper brain regions where the blood is cooler than the surrounding brain tissue. So it's really not a coolant in the same manner as that in a heat engine. The cbf actually heats up more superficial brain regions that are closer to the skull so the mechanism is not uniform. The main purpose of cerebral blood flow is to bring glucose to neurons for their basic energy need. So the cooling ability is sort of a secondary aspect of blood flow and is probably not ideally suited for that purpose. Evolution has basically co-opted one process for a different purpose entirely. The blood flow's ability to cool is more important for larger brained mammals and less relevant for smaller brained ones where heat can dissipate from the head easier.

The author of the paper notes some of the constraints of the brain taking into consideration excess heat production. He suggests that thinner axons/dendrites result in excess heat. However, he estimates that the axon's diameters are at a magnitude higher (averaging 12-1500 times) than the lower bound diameter that would be problematic. He also talks about the heat bounds relating to the propagation of neural signals and density of axonal packing. The author concludes that deep brain temperature is only weakly correlated with brain volume. So the brain could easily be scaled above the 5 kg limit of current land mammals. However, that is assuming that no other methods are utilized by evolution to "overclock" specific brain regions.

I think that evolution finds whatever way it can to increase the brain's computational capacity. I've mentioned previously about some of the possible ways. Evolution exploits any pathway easily available. The firing speed of neurons is an aspect of overall computational capacity. However there are limits to this facet of brain functioning. Neurons can only fire continuously so many times before the sodium concentration in the cell becomes too high. This is especially true if neuronal axons were to become too thin. Those Na+/K+ pumps can only pump sodium ions out of the neuron so fast in certain cases. Evolution can possibly add more pumps, but then that requires more energy which potentially generates more heat. The pumps work relatively slow, so even a maximum amount of them might not overcome a certain limit. Eventually you might run up into an insurmountable wall with this attribute of brain function. So evolution may have to do something else, like increase the overall amount of neurons.

Sometimes the path that evolution follows is unexpected. Average neuronal firing rates in larger brains are actually less frequent than that of neurons in smaller brains. So there may be some limitation to increasing neuronal firing rate over the course of evolution as you scale upwards in size. You would also think that evolution would first do something like maximizing the amount of proteins in the synapse before it went on to increase overall neuron count. However evolution tends to fill in some of these finer details later on, instead of in a logical linear fashion. Scientists will probably increasingly figure out why occurs as time goes on. The author of the paper does his part to elucidate a few of these possible constraints on how the brain is arranged.

With increasing brain complexity there is the potential for more pathways to open up that can be exploited to further increase overall computational capacity. With more complexity, however, there is also the possibility for evolution to have a harder time navigating a proper way forward. There may be too many entangled systems whereby changing the variable of one thing could have a negative effect on something else. When cerebral blood flow is too high, for instance, it can damage the brain. So evolution may not be able to just take obvious routes (like increasing brain blood flow speed) to decrease brain heat. Not to mention how blood flow is mainly involved with delivering energy to cells. So any change in cbf could potentially negatively affect that process as well. Short of developing a whole secondary cooling system, evolution is stuck co-opting cbf as a coolant system. Also more blood flow in the brain may mean less room for computational purposes. Of course, this paper indicates that increased cooling might not be necessary. It may tend to get difficult as evolution moves forward to undo things or reach a path that is radically different from what previously evolved. Evolution has to essentially make due with whatever it has.

In the past, scientists from Japan have constructed a "heat pipe" that can be implanted directly into discrete brain regions. This device can essentially be used to cool brain areas by diverting heat to an outside heat sink. The researchers developed this implant specifically for the purposes of reducing epileptic seizures. Over-excited neurons in an epileptic seizure are more active, use more energy and thus generate more heat. This excess heat that is generated can cause a feedback loop exciting more neurons to fire thus potentially prolonging the seizure. So cooling the brain could be a way of reducing problems associated with this condition. It is possible that this could be used to better regulate the temperature of future engineered brains.

I think the fact that our universe allows brains to evolve to the size they do may be an example of the anthropic principle. First, there is the rare earth perspective of life. Our planet is situated in a near perfect distance from the sun and is neither too hot nor too cold to sustain life. The gravitational pull of our planet may be at nearly the right level that allows a larger brain to evolve. Also our solar system is located far enough from the center of the galaxy so as to avoid excess radiation. These are only a few examples of our special situation in our own galaxy/universe. String theory predicts that our universe is merely one region out of a larger multiverse. In the multiverse there are different vacua that may have varying constants. A majority universes in the multiverse may not be able to sustain any life at all. Some universes may contain selfish replicators, but they never be able to evolve a nervous system or the capacity for sentience. Perhaps in an even smaller subset of vacua in the multiverse, a brain/nervous system can evolve, but maybe it cannot attain a complexity greater than that of a mouse's brain or an insect's or even less. There might be too many design constraints inherent to that specific universe for it to get any bigger. The physics of our own universe is perfectly suited to developing a human level intelligence. The heat capacity of water may allow the brain to maintain a fairly stable temperature, for instance. Definitely quite amazing when you think about. Perhaps we will eventually figure out everything related to this more speculative science in the future.

Karbowski, J. (2009). Thermodynamic constraints on neural dimensions, firing rates, brain temperature and size Journal of Computational Neuroscience DOI: 10.1007/s10827-009-0153-7

Brain Function and Ultrasound

noreply@blogger.com (Mike) — Mon, 25 May 2009 22:18:55 PDT

Researchers are using GPU processors to enhance the imaging capacity of ultrasound. (see GPU engine enhances ultrasound-detected brain motion calculations). They are specifically using an ultrasound transducer array (shown left) positioned around the head to detect brain tissue micropulsations. Obviously more computing power allows for better analyzing capability of ultrasound pulses. In the past other researchers have been working on better focusing of ultrasound, which could further enhance the images created. I've mentioned previously about some of the other intriguing applications of ultrasound. This new research shows a few interesting trends that are developing. I think a lot of the hard work has already been accomplished in successfully getting ultrasound pulses to focus on brain regions. So ultrasonic brain stimulation may become a simpler undertaking. It is basically riding on the back of all this other research that has already been done. Throw in a dash of an accelerating technological growth rate and the ability to manipulate the brain could increase quite dramatically and cheaply.

Could you have something worn on the head (like the device above) that would stimulate brain regions selectively? In theory, I don't see why not. 20 years down the line you may potentially be able to buy a neural stimulation device based on this principle. This may be technically possible, but I'm not sure how it could be done in a safe manner. It has been mentioned on other blogs that there is a site that seeks to build a home transcranial magnetic stimulation device (OpenStim). According to that page, the OpenStim project has been put on hold due to inactivity. At least one person in a forum has discussed about trying to use ultrasound for brain stimulation purposes. It seems premature to be doing something like this now when so little is known about its effects on brain chemistry. Maybe in the future a community will crop up attempting to build an "open source" ultrasonic neuromodulation device.

I'm relatively libertarian when it comes to a lot of mind alteration (at least when it comes to drugs). People have been manipulating their brain chemistry via the use of psychochemicals for quite some time. However this sort of brain stimulation seems like a different animal. It really requires a knowledge of what areas to target in the brain for a desired effect, which I think may be above most people. Maybe intuitive computer interfaces will allow people to offload the hard work to their PC. I do like the idea of giving people some autonomy over how they want to manipulate their brain. Open source brain manipulation coupled with the sharing of neural pathways associated with specific emotional states (using brain imaging and the internet) definitely sounds like an appealing future society. Perhaps with robust safety mechanisms in place, this could become a reality. With any brain alteration you have the potential to affect the balance of power between two individuals. Is it done for the good of the individual, or done for the good of society (i.e. other people)? What would a person use this brain stimulation device to accomplish? Definitely some interesting questions come up that don't have easy answers.

Brain Synapse Computational Capacity

noreply@blogger.com (Mike) — Wed, 03 Jun 2009 22:19:03 PDT

Researchers are uncovering another layer of complexity as to how the brain functions. Brain cells communicate with one another by chemicals through synaptic connections. The human brain contains billions of neurons and each neuron has a large amount of synaptic connections to other neurons. Each synapse itself contains a variety of receptor proteins that can alter the gross firing pattern of a neuron. It has only been recently that scientists have been able to better understand the role of synaptic protein interactions in the computational capacity of the brain. A lot of this activity functions at an even lower level than overall neuronal firing.

In the past, researchers have found that different organisms on the tree of life have varying amounts of these receptor proteins in the individual synapses of their neurons. As you go from simpler organisms up to mice, there are an increasing number of synaptic molecules. In that past study, the scientists had investigated approximately 651 different genes that directly encode for proteins in the postsynaptic junctions of mouse neurons. They specifically focused on proteins that can be phosphorylated. Phosphorylation of protein molecules changes their functioning. The researchers looked for the same proteins in a variety of other life forms besides mice that had varying levels of complexity (invertebrates, non-mammalian vertebrates and other mammals). Lower complexity organisms like invertebrates had about 45% fewer of these synaptic proteins than the mouse synapse, while an even simpler organism like yeast only had about 21% of the number of proteins.

Now those very same researchers have published more work uncovering the complex interactions of the molecular proteins in an individual synaptic connection.

Here, we define maps of molecular circuitry within the PSD based on phosphorylation of postsynaptic proteins. Activation of a single neurotransmitter receptor, the N-methyl-D-aspartate receptor (NMDAR), changed the phosphorylation status of 127 proteins. Stimulation of ionotropic and metabotropic glutamate receptors and dopamine receptors activated overlapping networks with distinct combinatorial phosphorylation signatures. Using peptide array technology, we identified specific phosphorylation motifs and switching mechanisms responsible for the integration of neurotransmitter receptor pathways and their coordination of multiple substrates in these networks. These combinatorial networks confer high information-processing capacity and functional diversity on synapses, and their elucidation may provide new insights into disease mechanisms and new opportunities for drug discovery.

The researchers of this specific work used proteomic and also computational methods to disentangle all the relationships between these synaptic proteins. So being able to determine these relationships is really in some respects on outgrowth of certain accelerating trends in computing power and protein/genetic analyzing capability. I mentioned previously that Henry Markram talked about how certain newly developed methods are vastly speeding up scientific research. Research in uncovering some of these molecular mechanisms has moved rather slowly in the past, but greater computing power and software analyzing capability has the capacity to greatly accelerate progress.

The researchers have found that all of these molecular networks in the synapse may underly some of the overall computational capacity of the brain. You can read more about it at the press release here.

The team's discoveries led researchers to the conclusion that the brain is organised like the internet, where billions of these molecular computers - intricately complex in themselves - are connected by billions of nerve cells.

So evolution has exploited multiple avenues to increase the brain's computational capacity. The avenues that were taken exist at differing "levels". Overall brain cell number is a "higher level" avenue. The human brain contains many more neurons than that of a mouse and other lower level organisms. Evolution has also favored mutations that cause increased branching and growth of neuronal axons. Mutations which increase levels of glucosylceramide in the brain, for instance, can increase the amount of neural axon terminals. There is evidence that recent evolutionary selection pressure on humans has favored mutations which alter the amount of glucosylceramide and that these specific mutations may lead to a higher intelligence. More axon terminals equal more synapses connecting each neuron. At a molecular "lower level", evolution has favored increasing the number of proteins in each individual synapse and a more complex interaction between those proteins. There are other potential ways that evolution may have worked on as well, which I won't mention here.

By merely simulating a higher level of brain functioning (overall neuron firing/activity) on a computer, researchers may totally miss a substantial amount of lower level functioning. So future computer brain simulations will likely have to model all of these protein interactions to function in a manner similar to a real brain. Even then, it is not clear if they will be successful in modeling the mind exactly (especially without the underlying physics of our world). I think you can probably model aspects of brain functioning very well on a computer, even with a simplified model (like without molecular interactions). However, getting a computer simulation of an entire brain to function exactly like a real brain (meaning it would have consciousness), may be a difficult task if not an impossible one. This new research, though, will certainly have an impact on our understanding of how the brain functions.

Encephalon 69th Edition

noreply@blogger.com (Mike) — Mon, 27 Apr 2009 17:15:11 PDT

Welcome to the 69th edition of the Encephalon blog carnival. This carnival is devoted to presenting blog posts that cover neuroscience and psychology related topics.

First up, Neuroanthropology does an in depth analysis about the twitter phenomenon in "Fear of Twitter: technophobia part 2". I personally have not been inclined to get on the twitter bandwagon. Do I have twitter phobia? Perhaps. Not sure if I'm interested in another time waster. A couple of topics in that article include a discussion about matters related to privacy and twitter's potential affect on cognitive processes.

Brain Blogger has a post about "Free Will and the Philosophy of Science". The author talks about the relationship between neuroscience and scientific determinism. There is further discussion about the topic in the comment section too. There is a little bit of confusion on the part of the blog post author and some of the commenters about whether the physics of our world is deterministic or not. The most widely accepted interpretation of quantum mechanics among physicists (many worlds) is deterministic. So does a deterministic world deny the existence of free will? Well I think that depends on how you define the term "free will". As mentioned by the blog post author in one of the comments, the term "free will" can be rather vague. So I think the discussion won't be particularly fruitful if you don't properly define what exactly "free will" is. It's a topic I myself might explore in a future post.

Sharp Brains writes on the subject of whether taking art classes can boost academic achievement in other fields in "Arts and Smarts: Test Scores and Cognitive Development". There is conflicting data as to whether participating in the arts is beneficial for test scores in more conventional domains (like math or reading ability). There is also the issue of whether correlation proves causation in some of the studies.

Neuroanthropology has another lengthy article that discusses about a "neuro" term in "Who you callin’ a ‘neuroconstructivist’?!". Another "neuro" word? What does neuroconstructivist mean? You'll have to read the post if you want to find out the whole story. It looks like part of being a neuroconstructivist entails taking environmental effects on the brain and its development more seriously. The expression of brain genes can be dependent on social environmental factors, for instance (i.e. social interactions). From my own reading of the Neuroanthropology blog, I tend to think they sometimes overstate the case for certain environmental social factors being able to shape an individual's brain to a desired output. Nonetheless, they usually have well reasoned posts. I also think it is important to stress that while the environment can have an impact on brain functioning, brain functioning itself can impact how we consciously perceive the environment. Changing brain chemistry (like by using a neuro drug as one extreme example) can alter our perception of reality (i.e. the environment) and this can affect all subsequent brain/environment interactions as a result of that altered perception.

Brain Blogger has another post discussing new objective testing methods for Alzhiemer's disease. Volumetric brain imaging analysis of the hippocampus can be used as a biomarker for Alzhiemer's disease. It's unfortunate that there aren't too many therapies that are truly effective in treating/preventing Alzhiemer's even with earlier detection. A lot of the new neurotechnologies discussed on my own blog will probably have only a limited effect on the disease process too. I also think it will be getting harder and harder to actually get FDA approval for many new neurological therapies in the future. The current regulatory environment is not conducive to this sort of thing and it will probably only get worse. Hopefully my pessimism will prove wrong.

Cognitive Daily has a post entitled "How wrong is it to use a kitten for personal ughhh... pleasure?". Very embarrassing post title to describe. It deals with one particular sort of kitty induced pleasure. Do we really need to be giving people these sorts of ideas? Aren't there enough weirdos out there who will try anything? The post talks about how people have a tendency of rating things as being more immoral when they are exposed to something else disgusting (fart smell, disgusting movie) that is unrelated to the poll. Conversely you can make people judge something as being more "moral" as well by having them do certain things beforehand (having them wash their hands, for instance).

Sharp Brains also mentions about a Cognitive Health Track at Games for Health Conference.

Well, that's it for now. The next Encephalon installment will be hosted at TBD, May 11th, 2009. More information about future editions of this blog carnival and details about making post submissions can be found at the Encephalon archive.

Brain Technology

noreply@blogger.com (Mike) — Fri, 24 Apr 2009 21:33:23 PDT

A talk about the Blue Brain project has recently been given at the European Future Technologies Conferfence. You can read some more stuff about it at this german site (they have an mp3 audio at that site, but it's in German unfortunately). Blue Brain seeks to simulate the functioning of the brain via a computer. Henry Markram is the main researcher on this project is. Markram is the founder of the Brain Mind Institute (BMI) and he has made some key insights about the functioning of neurons in the past.

Currently the researchers have completed the first phase of the project. It sounds like they still have only simulated 10,000 neurons and 30,000 synapses of a rat cortical column. The researchers are integrating the simulated brain into a virtual reality agent. So they will have a simulated animal that will be able to function in a virtual reality environment. This will allow researchers to view the changes in neuron functioning as the animal moves around its virtual environment. Markram told the conference "It starts to learn things and starts to remember things. We can actually see when it retrieves a memory, and where they retrieved it from because we can trace back every activity of every molecule, every cell, every connection and see how the memory was formed." It's probably too soon to say how successful this will be. I think it may be a stretch to say that they can actually create a brain with the properties of consciousness. So I'd be a little skeptical, but Markram probably knows more about this than I do.

In future phases of the project they will use faster supercomputers that will allow scientists to add more details to the simulation. They plan on simulating biomolecular pathways and also gene expression patterns. Here's an excerpt from Markram's keynote speech at the beginning of the conference (Shaping 21st Century Science and Society) that sounds very similar to Ray Kurzweil in many respects.

There is no sign that the exponential growth in computing power is decreasing which means that we will see a 1000 fold increase each decade (exascale (10^18) by 2020, zettascale (10^21) by 2030, yottascale (10^24) by 2040). Such a growth in computing power within our lifetime comes with extreme challenges where information and computational devices need to be energy-efficient, fault-tolerant, capable of self-repair, and where storing and processing of the vast volumes of information generated is carried out with novel automated and highly intelligent information processing systems. The exponential trends of minimizing size and cost and maximizing speed and efficiency are so extreme that the evolutions and revolutions in ICT over the next 10-20 years will be equivalent to those of the past 100 years.

Markram talks about 3 elements that are transforming science. He mentions that data acquisition is increasingly becoming automated. He says there has been an exponential growth in the amount of DNA being sequenced and he predicts that we will know the DNA sequence of all organisms on the planet in 3 decades. There is also a greater ability to process large amounts of data through the use of statistical correlations and machine learning. He also says the computerization of science is leading to increased collaboration and productivity.

I think it seems feasible that these computer simulations will eventually allow extremely personalized medicine. Brain scanning technology is continuing to get better, perhaps down the the molecular level. In the future a person may be able to get their brain scanned and then have a computer simulation of their brain on their home computer. Ray Kurzweil has talked a lot about these exponential technological trends and how they could transform what it means to be human. Will there be ways to increase human happiness or human intelligence exponentially in the future? Who knows. I think a lot of interesting things will become possible assuming these simulations become increasingly accurate and realistic in their portrayal of the human brain.

Artificial Brain

noreply@blogger.com (Mike) — Sun, 19 Apr 2009 13:30:47 PDT

I found a blog that has some more information about the DARPA SYNAPSE project. The SYNAPSE project seeks to create a neuromorphic artificial brain. That blog also has a bunch of older posts that specifically relate to this project. Will this actually lead to anything? I suppose it's always possible, but I guess I'm fairly skeptical that it will accomplish much.

SyNAPSE is a complex, multi-faceted project, but traces its roots to two fundamental problems. First, traditional algorithms perform poorly in the complex, real-world environments that biological agents thrive. Biological computation, in contrast, is highly distributed and deeply data-intensive. Second, traditional microprocessors are extremely inefficient at executing highly distributed, data-intensive algorithms. SyNAPSE seeks both to advance the state-of-the-art in biological algorithms and to develop a new generation of nanotechnology necessary for the efficient implementation of those algorithms.

Another blog also has some information that pertains to neuromorphic electronics.

“Neuromorphic engineering takes inspiration from the signal processing structures found in the brain and physical attributes of animals to design new computers and robots capable of the amazing sensorimotor feats seen in nature. From neurons to behavior, the low-power, robust, real-time, and adaptive nature of biological systems serves as a proof-of-concept of the unique implementation developed by evolution. These principles have been applied to software models of sensory processing, VLSI implementations of neural circuits, and robot design.”

Also I found this interesting paper called "Framework and implications of virtual neurorobotics" (PDF) that discusses about using virtual reality environments to further the development of neuromorphic electronics.

More recently, investigators are focusing on the core assumptions of the brain “algorithm” itself—trying to replicate uniquely “neuromorphic” dynamics such as action potential spiking and synaptic learning. Only now are large-scale neuromorphic models becoming feasible, due to the availability of powerful supercomputers and an expanding supply of parameters derived from research into the brain’s interdependent electrophysiological, metabolomic and genomic networks. Personal computer technology has also led to the acceptance of computer-generated humanoid images, or “avatars”, to represent intelligent actors in virtual realities. In a recent paper, we proposed a method of virtual neurorobotics (VNR) in which the approaches above (social-emotional robotics, neuromorphic brain architectures, and virtual reality projection) are hybridized to rapidly forward-engineer and develop increasingly complex, intrinsically intelligent systems. In this paper, we synthesize our research and related work in the fi eld and provide a framework for VNR, with wider implications for research and practical applications.

I don't see much discussion about the ethics of doing this type of research. I'm not sure if they are attempting to make artificial brains that are conscious or not. Bringing about a conscious AI could have a variety of ethical implications. Most likely, though, progress in this field will be fairly slow. I wouldn't expect much to happen for quite some time, if at all.

Religious Pill

noreply@blogger.com (Mike) — Fri, 10 Apr 2009 09:43:22 PDT

Does a selective drug exist that could increase a person's spirituality and religiosity? Are there pills available that would allow a person to suffuse their perceptual consciousness with a feeling of the presence of an otherworldy supreme being? Will the very same drug increase feelings of serenity, peace and magic? I mentioned previously about a British psychiatrist who argued that we could use drugs to enhance specific traits of humanity. What does neuroscience have to say about human spirituality?

Serotonin is a neurotransmitter involved in the regulation of a variety of brain processes. There are a number of different serotonin receptors that are located in various brain regions. In the past, researchers have correlated a specific serotonin receptor (5-ht1a) with scores of self-transcendence. The 5-ht1a receptor is located in the dorsal raphe nuclei, the hippocampus, and the neocortex. The researchers found that people who had the lowest density of 5-ht1a receptors in these key areas were more "spiritual" on average than people with a higher number of 5-ht1a receptors. There are several different interpretations of this specific research. A lower number of 5-ht1a receptors could mean one of many things. Usually when a receptor is being overactivated by a neurotransmitter, though, it downregulates or decreases in number. So a lower density of 5-ht1a receptor probably means that the receptor is being activated at an increased rate.

Several drugs like MDMA, LSD and psilocybin have an effect on the 5-ht1a receptor. All of these drugs have the capacity to increase perceptual feelings of otherworldliness. MDMA is an indirect agonist that increases 5-ht1a receptor activation by causing a massive increase of actual serotonin in the synapse. Psychedelics like LSD and psilocybin, on the other hand, directly activate the 5-ht1a receptor without the need for serotonin. They act as false neurotransmitters and can increase activity at that specific receptor (partial agonism). Psilocybin specifically has been known to sometimes induce serene spritual experiences that have a very profound perceptual conscious value. Psilocybin's action on the 5-ht1a receptor may be part of the reason the drug is able to amp up spiritualism and feelings of being one with the universe. These drugs are hardly usable for most people, though. They instill states of consciousness that are far too radical for people to live on regularly. They are fairly dirty drugs that have a wide range of effects on a variety of other neuroreceptors. There may, however, exist more selective drugs which a person could responsibly use every day that don't induce hallucinations.

Currently there is evidence that a main component of the mood elevating effect of serotonin boosting drugs is the result of agonism/activation of post-synaptic 5-ht1a receptors. Activation of other serotonin receptors like 5-ht2a, 5-ht2c and 5-ht3 may be more associated with the adverse side effects of SSRI's like sleep problems, anxiety and apathy. A selective serotonin reputake inhibitor (SSRI) is basically a drug that non-selectively activates all types of serotonin receptors by increasing serotonin in the synapse. Do SSRI's have the capacity to amp up feelings of supernaturalism as a result of their capacity to increase 5-ht1a activation? My guess is that they might. However SSRI's can also have a negative impact on dopaminergic functioning especially in the prefrontal cortex due to their non-selective effect on other 5-ht receptors. This can often leave a person more apathetic, demotivated and having a reduced sense of joy for life. I would imagine killing your dopaminergic functioning is scarcely a recipe for spiritual motivation.

There is perhaps a more promising approach. Buspirone is a 5-ht1a partial agonist that has mood elevating properties and is FDA approved for treating anxiety. Buspirone acts as a false neurotransmitter and directly engages the 5-ht1a receptor. By activating the 5-ht1a autoreceptors it actually decreases serotonin in the synapse and subsequently decreases activation of all 5-ht receptors (by serotonin). However buspirone directly activates postsynaptic 5-ht1a receptors at an increased rate. So buspirone doesn't have the same negative effect on dopaminergic function as SSRI's. Postsynaptic 5-ht1a receptor activation (specifically in the hippocampus and neocortex) may be associated with a mood elevating effect, an increased sense of self-transcendance and a feeling of inner peace. So I would imagine that buspirone probably has a greater likelihood of boosting a person's feelings of spirituality. Perhaps even more selective and potent 5-ht1a agonists (sometimes referred to as serenics for their propensity to reduce anxiety) will become available at some future date.

How would a company go about marketing a pill to make you more religious? Would they have to concoct a new brain disorder (low spiritual acceptance disorder perhaps)? I think feelings of this sort could be of perceptual value, even if you are an atheist. Some conscious states induced by specific drugs can be extremely profound and life changing. I think greater control of our brain processes (perhaps through neurotechnology) will allow for a fine tuning of perceptual qualia. The future could definitely be interesting as we are increasingly able to shape our perception to whatever we so desire.

Brain Mapping

noreply@blogger.com (Mike) — Sat, 11 Apr 2009 09:27:50 PDT

There's a new paper in PLoS Biology entitled "A Computational Framework for Ultrastructural Mapping of Neural Circuitry". Researchers from two different universities have teamed up to create accelerated brain mapping capabilities. The researchers are using transmission electron microscopes (TEMs) to map specific brain regions. Previously the work to map brain regions could take years. Now, though, they have created more powerful software that enables a faster analysis of TEM created brain images. Here's an excerpt from the abstract;

We have assembled a complete framework for ultrastructural mapping using conventional transmission electron microscopy that tremendously accelerates image analysis. This framework combines small-molecule profiling to classify cells, automated image acquisition, automated mosaic formation, automated slice-to-slice image registration, and large-scale image browsing for volume annotation. Terabyte-scale image volumes requiring decades or more to assemble manually can now be automatically built in a few months. This makes serial-section transmission electron microscopy practical for high-resolution exploration of all complex tissue systems (neural or nonneural) as well as for ultrastructural screening of genetic models.

According to the press release the authors of this paper expect to have a molecular map of an entire mammalian retina including the neuronal networks very shortly. So this should be useful for understanding specific types of disorders.

Meanwhile there is another new challenge that has been assigned an unusual acronym. It's basically a competition among researchers to find faster ways to map the brain.

The organizers hope the DIADEM Challenge—short for Digital Reconstruction of Axonal and Dentritic Morphology—will lead to innovative solutions to a frustrating problem that has slowed efforts to create a functional atlas of the brain. Neuroscientists agree that a systematic characterization of neurons with their dendrites and axons is essential, since these tree-like structures are highly correlated with the electric activity of, and precise connections between, neurons and are thus linked to the functions of specific brain circuits. But scientists currently spend weeks—and, in some cases, months—tracing the intricate neuronal processes by hand, using data supplied by imaging studies.

There is a DIADEM challenge website that is up already. It is definitely going to be interesting as these type of brain maps become more common place. They should be very useful for understanding the workings of the brain.