Brain Rules

Why the Brain Craves Exercise and Sleep

noreply@blogger.com (John Medina) — Fri, 10 Jul 2009 16:04:00 +0000

John Medina's discusses exercise, attention, and sleep in his interview on KING5 (NBC) News. Watch on YouTube.

Other News
- Brain Rules is #8 on the New York Times Business bestseller list
- Bonus interview with John Medina
- Brain Rules is available on the iPhone, Kindle, and Sony Reader

Functional Magnetic Resonance Imaging: Round 2

noreply@blogger.com (John Medina) — Tue, 30 Jun 2009 21:34:00 +0000

This is the second installment in a 3-part series (read 1st column here) that discusses some of the mechanisms behind functional magnetic resonance imaging (fMRI) technology. As you may recall, the genesis for this series was reactive…I got mad while sitting on an airplane reading a magazine article about how fMRIs can predict everything from product preferences to political inclination. The article hinted at something I have been noticing with increasing alarm—the confusion about what fMRI can and cannot reveal about information processing in the brain. I decided to write this series hoping that knowledge of the basic science behind fMRI technology could contribute to making more nuanced conclusions about the data it reveals.

Last month, I discussed some of the basic physics behind MRI and described why magnets and radio waves were so important in getting an image. Here I explore how that physics reveals neural activity in the brain. Actually, fMRI does not detect neural activity at all. It only detects changes in blood flow, which may be a source of some of the confusion (more on that in a moment).

To talk about the controversies about what fMRI actually detects (and yes, there are controversies), I will briefly describe the relationship between neural activity and the brain’s hemodynamic properties. I will then move to data that appear to describe the molecular components behind this relationship. Along the way, I will review some basic biochemistry, from glycolysis (remember glycolysis?) to the prostaglandin biosynthetic pathway.

Read the article

Your brain is built to deal with stress that lasts about 30 seconds

noreply@blogger.com (John Medina) — Tue, 23 Jun 2009 00:00:00 +0000

You can feel your body responding to stress: Your pulse races, your blood pressure rises, and you feel a massive release of energy. That’s the famous hormone adrenaline at work. It’s spurred into action by your brain’s hypothalamus, that pea-size organ sitting almost in the middle of your head. When your sensory systems detect stress, the hypothalamus reacts by sending a signal to your adrenal glands, lying far away on the roof of your kidneys. The glands immediately dump bucketloads of adrenaline into your bloodstream. The overall effect is called the fight or flight response.

But there’s a less famous hormone at work, too—also released by the adrenals, and just as powerful as adrenalin. It’s called cortisol. You can think of it as the “elite strike force” of the human stress response. It’s the second wave of our defensive reaction to stressors, and, in small doses, it wipes out most unpleasant aspects of stress, returning us to normalcy.

Why do our bodies need to go through all this trouble? The answer is very simple. Without a flexible, immediately available, highly regulated stress response, we would die. Remember, the brain is the world’s most sophisticated survival organ. All of its many complexities are built toward a mildly erotic, singularly selfish goal: to live long enough to thrust our genes on to the next generation. Our reactions to stress serve the live-long-enough part of that goal. Stress helps us manage the threats that could keep us from procreating.

And what kinds of sex-inhibiting threats did we experience in our evolutionary toddlerhood? It’s a safe bet they didn’t involve worrying about retirement. Imagine you were a cave person roaming around the east African savannah. What kinds of concerns would occupy your waking hours? Predators would make it into your top 10 list. So would physical injury, which might very well come from those predators. In modern times, a broken leg means a trip to the doctor. In our distant past, a broken leg often meant a death sentence. The day’s climate might also be a concern, the day’s offering of food another. A lot of very immediate needs rise to the surface, needs that have nothing to do with old age.

Why immediate? Most of the survival issues we faced in our first few million years did not take hours, or even minutes, to settle. The saber-toothed tiger either ate us or we ran away from it—or a lucky few might stab it, but the whole thing was usually over in less than half a minute. Consequently, our stress responses were shaped to solve problems that lasted not for years, but for seconds. They were primarily designed to get our muscles moving us as quickly as possible, usually out of harm’s way. You can see the importance of this immediate reaction by observing people who cannot mount a thorough and sudden stress response. If you had Addison’s disease, for example, you would be unable to raise your blood pressure in response to severe stress, such as being attacked by a mountain lion. Your blood pressure would drop catastrophically, probably putting you into a state of debilitating shock. You would become limp. Then you would become lunch.

These days, our stresses are measured not in moments with mountain lions, but in hours, days, and sometimes months with hectic workplaces, screaming toddlers, and money problems. Our system isn’t built for that. And when moderate amounts of hormone build up to large amounts, or when moderate amounts of hormone hang around too long, they become quite harmful. That’s how an exquisitely tuned system can become deregulated enough to affect a dog in a metal crate—or a report card, or a performance review.

Learn more about Brain Rules.

BRAIN RULE RUNDOWN

Rule #8: Stressed brains don't learn the same way.

Your brain is built to deal with stress that lasts about 30 seconds. The brain is not designed for long term stress when you feel like you have no control. The saber-toothed tiger ate you or you ran away but it was all over in less than a minute. If you have a bad boss, the saber-toothed tiger can be at your door for years, and you begin to deregulate. If you are in a bad marriage, the saber-toothed tiger can be in your bed for years, and the same thing occurs. You can actually watch the brain shrink.
Stress damages virtually every kind of cognition that exists. It damages memory and executive function. It can hurt your motor skills. When you are stressed out over a long period of time it disrupts your immune response. You get sicker more often. It disrupts your ability to sleep. You get depressed.
The emotional stability of the home is the single greatest predictor of academic success. If you want your kid to get into Harvard, go home and love your spouse.
You have one brain. The same brain you have at home is the same brain you have at work or school. The stress you are experiencing at home will affect your performance at work, and vice versa.

View Stress and the brain tutorial

Stress at work video

Stress References (PDF)

Happy marriage can equal happy baby

noreply@blogger.com (John Medina) — Mon, 04 May 2009 21:11:00 +0000

People love to give advice to expectant couples. Some of it is trite ("Cherish every moment"); some is useful ("Go to as many movies as you can before the baby comes").

But no one warns couples about what can happen to a marriage after the baby arrives.

Read "Happy marriage can equal happy baby" in the St. Louis Post-Dispatch.

SOURCES FOR THE STUDIES

From where do the statistics on the transition to parenthood come? The comments in this article probably need to have some nuance added to them in order to make the most sense. These additional comments are enumerated below, including the references for all figures cited here and in the above sections.

It is clear that marital satisfaction declines for both members of the couple, sometimes catastrophically, during the transition to parenthood. The female in the relationship generally achieves the 70% figure first (though in some studies the actual figure is between 40 -70%). The male satisfaction scores starts declining afterward, perhaps as a reaction to female behavior. Here are two relevant references:

Gottman, JM (1999)
The Marriage Clinic: a Scientifically-Based Marital Therapy
Norton Prof Books (NY)
pp. 119 – 133 (see in particular p. 120 – 121)

Belsky, J and Pensky E (1988)
Marital change across the transition to parenthood
Marr and Fam Rev 12: 133 – 156

The nine-fold figure at the half-year mark is actually from unpublished data. The true number has been elusive to determine, even after all these years, probably because different studies use different hostility indices to arrive at their conclusions. Regardless of the methodology employed, the conclusion is very straightforward, and sobering: it is not abnormal to experience a great increase in conflict during the transition to parenthood (for some couples, it is probably much higher than 9x). Here are references filled with the most solidly designed studies:

Wallace, PM & Gotlib IH (1990)
Marital adjustment during the transition to parenthood: stability and predictors of change
J. Mar & Fam 52(1): 21 – 29

Belsky, J and Kelly J. (1994)
The transition to parenthood: How a first child changes a marriage and why some couples grow closer and others apart
Dell (NY)

Learn more about Brain Rules.

This is Your Brain at Work

noreply@blogger.com (John Medina) — Tue, 28 Apr 2009 16:28:00 +0000

John Medina was recently interviewed by the New York Post. The complete article, "This is Your Brain at Work," is available here.

How is work an antibrain environment?

We don't very much know how the brain works, but we do know something about its performance envelope. The brain appears to have been designed to solve problems related to surviving in an outdoor setting in unstable meteorological conditions. And to do that in near-constant motion. That's what the brain's good at. So if you wanted to design a work environment directly opposed to what the brain was naturally good at doing, you'd design something like an office.

If you tore the workplace down, what would you replace it with?

We've known for some time that the more fit aerobically you are, the better a particular series of processes called "executive function" in the brain works. It helps your ability to do math. It helps your ability to control your impulses. It helps with Let's say you're a Boeing engineer. Executive function is the very thing that allows you to design a satellite and, at the same time, keeps you from punching your boss in the nose when you get a bad performance review.

If you take somebody who's fat and sedentary and exercise them three times a week for as little as three months, you can get anywhere between an 80 and 120 percent increase in executive function. In our evolutionary history, we were probably walking anywhere between 10 and 20 kilometers per day. If we sat around in the Serengeti for half an hour, we were usually lunch.

Scotch the cubicle, put in a treadmill and do all your computer work while you're walking two miles an hour.

How does sleep, or lack of it, affect the brain at work?

There's a time in the afternoon when your brain wants to do a reset. And during that time it wants to take a 15- to 20-minute nap. We call it the nap zone. If you don't allow yourself to take a nap during that time, you'll fight being sleepy the rest of the afternoon, and productivity can suffer.

It was measured by NASA. They were able to show that by giving their fighter pilots a 20-minute nap in the nap zone, you'd find an increase of about 34 percent in their mean reaction time performances.

Mark Rosekind, the guy who did the study, goes, "Look, what other management technique can I do that, in 20 minutes, gives a 34 percent boost in productivity?"

Brain Rules for public speaking

noreply@blogger.com (John Medina) — Wed, 22 Apr 2009 18:37:00 +0000

Scott Berkun recently interviewed John Medina for his blog Speaker Confessions. Scott asks the question: what makes public speakers good or bad? He's working on a book to answer that question.

SB: How can a lecturer use attention, but make sure not to abuse it? Or put another way, does repetitive use of phasic alertness, getting an audience to refocus their attention ever few minutes, have declining effects over time?

JM: I do not believe in entertainment in teaching, during the holy time information is being transferred from one person to another. I do believe in engagement, however, and there is one crucial distinction that separates the two: the content of the emotionally competent stimulus (“hook”). If the story/anecdote/case-history is directly relevant to the topic at hand (either illustrating a previously explained point or introducing a new one), the student remains engaged. Cracking a joke for the sake of a break, or telling an irrelevant anecdote at a strategic time is a form of patronizing, and students everywhere can detect it, usually with resentment, inattention or both.

Do you think the size of a classroom has any effect on students ability to pay attention? Does Posner’s model of attention change if we are alone in conversation, vs. in an audience of 99 other people listening to a lecture?

I don’t think the size of the classroom has anything to do with the functional neural architecture proposed by Posner, but there is a universe of difference in how it behaves. The behavior has to do with our confounded predilection for socializing. People behave very differently in large crowds than they do in small crowds or even one on one. Very different teaching strategies must be deployed for each.

Bligh’s book “What’s the use of Lectures?” identifies 18-25 minutes, based on his assesment of psychology studies, as the key breakpoint for human attention in classrooms. Whether it’s 10 or 25, why do you think so few schools or training events use these sized units as the structure for their days, or their lessons?

I don’t know why schools don’t pay attention to attention. Perhaps it is a lack of content knowledge. If I had my way, every teacher on the planet would take two courses: First, an acting course, the only star in the academic firmament capable of teaching people how to manipulate their bodies and voices i to project information. Second, a cognitive neuroscience course, one that teaches people how the brain learns, so teachers can understand that such projections follow specific rules of engagement.

The Physics of fMRI

noreply@blogger.com (John Medina) — Mon, 13 Apr 2009 18:05:00 +0000

I almost destroyed the backseat pocket of an airline seat this summer. The vandalism was inadvertent, assuredly, though the anger that fueled it was not. While waiting for my plane to take off, I had read a magazine article claiming to show that fMRI (functional magnetic resonance imaging) studies were “uncovering” the voting preferences of test subjects. An adjacent article announced that researchers could now predict the buying preferences of other test subjects using the same imaging technologies.

I was puzzled. How could Fourier transforms performed on signals coming from someone’s cortex say anything about their politics? What could possibly have reduced the interpretation of these noninvasive imaging data to conceptual phrenology? I got so mad as I thought more about it that I jammed the articles back into the pocket, aggravating an already ripped inner seam.

The column you are reading is an attempt to push this admittedly hot reaction into a more positive direction. . . and for a good reason. There are growing numbers of articles in the popular press describing “breakthroughs” in our understanding of human cognition—and how noninvasive imaging data are changing the way we view the brain. Nothing wrong with that, certainly. There has been an explosion of studies using functional (f)MRI technologies and their like. But are the data being revealed strong enough to predict subjective behaviors, such as voting habits? As you can probably guess from my tone, the answer of this bioengineer is “no,” or at least “not yet.”

I have decided to do something positive about these “headlines.” For now, and in my next 2 columns, I will describe how fMRIs actually work and what is the least luxurious, most conservative way to interpret the view they give us about cognition. Given the conceptual and technical complexity, it is easy to misconstrue what imaging technologies can divulge about human cognition.

Starting with quarks (literally) and ending with scans of emotional behavior, we will explore some of the biophysical underpinnings of this promising (and may I say limited) technology. The hope is that by knowing a bit about the technical aspects of fMRI, we will better understand what it can—and cannot—measure. This will allow us to treat with greater skepticism, and more sobered excitement, the view that fMRIs are giving us about how our brains work.

This first installment deals with some basic physics. I review a few properties about magnets and radio waves that you might not have thought about since your undergraduate days. In part 2, I will focus on the types of molecular interactions these magnets and radio waves actually measure when trained on an actively thinking brain. The third column will relate how this knowledge reveals both the strengths and limitations of using imaging technologies to discover aspects of human cognition.

THE 40,000-FOOT VIEW
We begin with the name. As you know, fMRI is short for functional magnetic resonance imaging. The core idea of fMRI has been around for a long time. Originally called just NMR (nuclear magnetic resonance), this technology found great utility in the organic and inorganic laboratories. When it came time to apply the technology to biological tissues (from ideas originally developed by Paul Lauterbur), the word “nuclear” was thought to have too many negative connotations. It was dropped in favor of the more socially compatible “functional.”

To understand how an fMRI scanner generates images, we have to break the machine down into its component parts. All fMRIs possess 3 general “gadgets.” The first is a device that can generate a powerful magnetic field. The second is a coil that can create powerful radio frequency pulses. The third is a highspeed computer, preloaded with a lot of very sophisticated signal processing software, all programmed to produce an image capable of making sense to a researcher. How these 3 gadgets work together is fairly easy to understand, at least at the 40,000-foot level. The magnet in the fMRI transforms tissues into a visualizable state; the radio frequency pulses provide the signaling information necessary to discern them. The computer assembles the information from the radio frequency pulses into a form instantly recognizable to anyone who can read a weather map. Indeed, part of the problem with misinterpreting fMRIs is that the information seems so accessible.

To make sense of how these gadgets work together, we have to understand how magnets and radio frequencies act at the subatomic level. These interactions are essentially the same physical
processes you see on display every time you turn on your radio.

Download the PDF to read the rest

This column appeared in the April issue of Psychiatric Times. More columns available here.

Paperback Available Now and Summer Workshops

noreply@blogger.com (John Medina) — Tue, 31 Mar 2009 18:28:00 +0000

The following was emailed to our Brain Rules Newsletter subscribers. If you want to receive email updates about 2x a year, sign up to subscribe to the newsletter.

Brain Rules Paperback Now in Stores
We are happy to report that the Brain Rules paperback is now available. The paperback includes a special link to watch the DVD online. You can pick up a copy at any bookstore. Links to buy online are here.

Brain Rules Workshops
Spend a day with John Medina as he takes the research and ideas in Brain Rules to the next level. Seattle Pacific University is hosting Brain Rules for Education (for teachers, principals, superintendents, and administrators).

Brain Rules for Education- Seattle
Thursday, June 25, 2009
OR
Thursday, July 16, 2009
8:30 am - 4:30 pm
Register and learn more: http://tinyurl.com/brainruleseducation

Register now to secure your spot as seating will be limited.

Cool Links to Share
There's a ton happening online related to the book. Here are some links to check out:

Sleep Well, Think Well - learn why we spend 1/3 of our lives sleeping
Brain Rules for Presenters - Garr Reynolds shows how Brain Rules relates to presentations
YouTube - more than 30 Brain Rules videos
Authors@Google talk - watch John Medina's 50-minute talk at Google
Tutorials - explore each brain rule through charts, audio, and video
Twitter - follow the action on Twitter
Mind Map - interactive outline of all 12 Brain Rules
Facebook - become a fan of John's, watch videos, discuss the book, and more

Brain Rules T-Shirts
We now have our own t-shirts. If you'd like a free t-shirt, order 7 copies of either the paperback or hardcover from an online bookseller by April 15, 2009 (tax day). Simply forward your email receipt to brainrulesbook@gmail.com with the subject "t-shirt." Let us know your size and mailing address. Offer is only good for U.S. addresses.

Thanks for sharing this with your friends and colleagues. Remember, curiosity is everything.

Mark Pearson
Pear Press

P.S. If you received this email from a friend, sign up to subscribe to the newsletter.

The 10 Minute Rule

noreply@blogger.com (John Medina) — Thu, 19 Mar 2009 02:26:00 +0000

So I ask this question in every college course I teach: “Given a class of medium interest, not too boring and not too exciting, when do you start glancing at the clock, wondering when the class will be over?” There is always some nervous shuffling, a few smiles, then a lot of silence. Eventually someone blurts out:

“Ten minutes, Dr. Medina.”

“Why 10 minutes?” I inquire.

“That’s when I start to lose attention. That’s when I begin to wonder when this torment will be over.” The comments are always said in frustration. A college lecture is still about 50 minutes long.

Peer-reviewed studies confirm my informal inquiry: Before the first quarter-hour is over in a typical presentation, people usually have checked out. If keeping someone’s interest in a lecture were a business, it would have an 80 percent failure rate. What happens at the 10-minute mark to cause such trouble? Nobody knows. The brain seems to be making choices according to some stubborn timing pattern, undoubtedly influenced by both culture and gene. This fact suggests a teaching and business imperative: Find a way to arouse and then hold somebody’s attention for a specific period of time.

"10 Minute Rule" slide with audio

To learn more about how Brain Rules relates to presentations, check out Garr Reynolds's Brain Rules for Presenters slideshow. Garr is the author of Presentation Zen.

Brain Rules for Presenters

View more slideshows:
Exercise
Sleep
Stress
Gender

Fishing for Genetic Links in Autism

noreply@blogger.com (John Medina) — Thu, 05 Mar 2009 04:51:00 +0000

This is the second installment in a 2-part series that addresses approaches to understanding the molecular underpinnings of autism. Learn more about "Brain Rules" here.

In my January column (“Fishing Expeditions and Autism: A Big Catch for Genetic Research?” Psychiatric Times, January 2009), I described the great difficulties researchers face characterizing the genetic basis of the disease. Complexities range from trying to establish a stable diagnostic profile to making sense of the few isolated mutations that show clear associations (either with disease or syndrome variants).

Using the metaphor of a fishing net, I discussed 2 overall research strategies that geneticists commonly use to catch these elusive sequences of interest. One strategy is to cast nets that act like large purse seiners to collect many sequences in a single (and usually quite expensive) effort. The other strategy is akin to dropping a single fishing line into the genetic waters to see if anything “bites.” In Part 1, I described one particularly successful strategy that snagged a large number of useful sequences.

Here, the focus narrows: I will not describe the isolation of many sequences, but rather only one. Our “catch” is called MeCP2, a gene whose mutations can give rise to a wide spectrum of related postnatal neurodevelopmental disorders—including autism spectrum disorders. I will start with some background regions about gene regulation, move to the biological functions of MeCP2, and then focus on studies in animal models that provide tantalizing hints about the origins of autistic behavior. My goal is to show that research progress in autism is a continuum of efforts, ranging from large projects with lots of identifiable sequences to small projects that focus on the properties of single genes.

Download the PDF of the complete article

Related:
- Theory of Mind

Fishing Expeditions and Autism: A Big Catch for Genetic Research?

noreply@blogger.com (John Medina) — Wed, 11 Feb 2009 17:13:00 +0000

This article first appeared in the Psychiatric Times. Learn about Brain Rules here.

I am a fan of the television show Deadliest Catch—a documentary series that follows the travails of deep-sea fishermen in the Bering Sea. (Actually, it is mostly about deep crab fishing.) Living in Seattle, I have actually seen some of the boats filmed on the show.

The variety of equipment the fishermen use to capture sea life is extraordinary. Trawlers and purse seiners—boats that use long-line nets and gill nets—make it possible to catch thousands of fish at a time. I am constantly struck by the comparison between these large, industrial efforts and the “weekend” fishermen that Seattle also has by the thousands. The amateurs use simple fishing poles to catch one fish at a time. Where the Deadliest Catch boats are based, you can often see both styles side by side.

I mention these 2 contrasting styles of fish harvesting because there is a comparison that I would like to make in this month’s column and in the next. It is not much of a stretch to say that isolating the genes responsible for complex behavioral disorders can seem like fishing expeditions (complete with analogous net comparisons). There are giant efforts that deploy the molecular equivalent of purse seiners designed to snag large groups of genes that share a potential involvement in whichever presenting behavior is under study. These efforts can be contrasted with technologies that use the equivalent of small fishing poles, the goal of which is not to catch large, glittering groups of nucleotides but single genes, one at a time.

In this column and the next, we will tackle one of the most slippery issues in the behavioral sciences: the genetic basis of autism.

Download the PDF of the complete article

Is There a Gene for Postpartum Depression?

noreply@blogger.com (John Medina) — Thu, 22 Jan 2009 16:29:00 +0000

This article first appeared in the Psychiatric Times. Learn about Brain Rules here.

The transition to parenthood is filled to the brim with behavioral extremes. Parents who are otherwise emotionally stable are in one moment thrilled and happier than they have ever been and confused and fearful the next. A friend of mine once theorized that these reactions occur because “parenting is an amateur sport” played by persons who are highly motivated to do the right thing but who often have no idea what that right thing is.

For some couples, the transition to parenthood is not filled with this rich mixture of great perplexity and great joy. For them, parenthood is mostly filled with sadness and even despair. Postpartum depression was originally coined to describe this experience in the mother, although it is becoming clear that fathers can experience very similar emotions too.

Is there a molecular basis for postpartum depression—at least for the type that mothers experience? Recent findings, which I describe here, may answer this question. First, we will focus on several background behavioral and molecular issues and then move on to some interesting data about births in genetically manipulated laboratory animals.

Download the PDF to read the complete article

Get brain in gear for new year

noreply@blogger.com (John Medina) — Thu, 01 Jan 2009 17:38:00 +0000

People sometimes make New Year's resolutions for the wrong reason.

John Medina knows a lot about how people operate. He doesn't make resolutions, but he does have some advice for anyone who wants to have a better life in 2009. Take care of your brain.
--Read Jerry Large's column in the Seattle Times

--Excerpt below from Compete.com interview

Given the 12 Brain Rules, what advice do you have for marketers?

Three pieces of advice:
1. The brain is not interested in learning. And it is not interested in buying. It is interested in surviving.

2. It fleshes out this pre-occupation by creating and responding to two internal motivations, both strikingly Darwinian. The brain is interested in anything that will provide it a benefit. And it will do whatever it can to avoid pain.

3. Both motivations are related to a single goal: passing our genes onto the next generation. That sounds like it all comes down to sex, but it really comes down to endurance – in terms of millions of years. We barely survived our womb in the Serengeti, but we did so because of the overwhelming dictatorship of these twin interior forces.

H.M., a man with no hippocampus, dies at 82

noreply@blogger.com (John Medina) — Mon, 29 Dec 2008 19:45:00 +0000

Each time Suzanne Corkin met H.M. during one of his visits to the Massachusetts Institute of Technology, she would ask him if they had met before. He would smile and say yes, and when she asked him where he would reply, “In high school.” They did not actually meet until he was in his late 30s, but they worked together for nearly five decades, and the last time they met he still failed to recognise her. The most she ever elicited in him was a sense of familiarity.
Economist Obit

John Medina explains how H.M. helped us understand how memory works (watch on You Tube).

Brain Rules in HD

noreply@blogger.com (John Medina) — Thu, 27 Nov 2008 19:13:00 +0000

Watch the introduction to the Brain Rules DVD below in HD (or here). The DVD is included with every hardcover book.

Below is the exercise segment in HD. You can also view it here. To learn more about how exercise boosts brain power, check out the exercise tutorial.

Painting Neural Circuitry With a Viral Brush: Are the Neighbors Green?

noreply@blogger.com (John Medina) — Fri, 07 Nov 2008 00:02:00 +0000

Note: This is the second installment of a two-part series describing the use of engineered rabies viruses in the elucidation of neural circuits. These columns appear in the Psychiatric Times. Learn about Brain Rules here.

In last month’s column (“Painting Neural Circuitry With a Viral Brush,” Psychiatric Times, October 2008), I used Michelangelo’s famous fresco, “Hand of God Giving Life to Adam” on the ceiling of the Sistine Chapel as a metaphor to introduce a series of technologies that have allowed researchers to map the complex interactions of neural connections in continuously functioning neural tissues. This technology promises to deliver accurate synaptic associations—one finger to another—at a very high level of resolution.

These extraordinary cartographic techniques involve exploiting the natural ability of the rabies virus to set up productive infections in neural tissues. For simplicity’s sake, we are examining the genetic manipulation of hypothetical “Neuron A” and its reaction to a previously engineered rabies virus. Although the manipulations to the virus are complex, using the data obtained, researchers seek to answer a simple, seemingly innocuous question: Are the neighbors green?

In case you do not have last month’s column handy, let me briefly review the life cycle of the rabies virus and reexamine the reengineered virus and Neuron A. We can then turn directly to the data.

Rabies virus

As mentioned last month, the rabies virus has several biological aspects that make it an ideal delivery device for working with living neural tissues. Once inside a nerve cell, the virus sets up a manufacturing site to create more viruses, like any typical virus. At maturity, however, these progenies jump to neighboring neurons, which allows the virus to spread along specific neural routes. This life cycle is handy if you are interested in synaptic connections throughout the body.

The infection can start in the peripheral nervous system and then jump the stout molecular border that separates it from the CNS. (That is why a bite anywhere on the body can result in a catastrophic brain infection.) If one could find a way to follow the virus, one could identify the routes by which it travels.

Aspects of this jumping ability were exploited in the circuit-mapping experiments we are about to review. Both virus and cell had to be genetically manipulated in 3 different ways for the experiment to work.

Download the PDF to read the complete article

McGurk Effect

noreply@blogger.com (John Medina) — Thu, 23 Oct 2008 20:32:00 +0000

Is he saying "ba ba" or "da da"? It's called the McGurk Effect. If you can't see the video, watch it on YouTube.

Brain Rules BNET Podcast

noreply@blogger.com (John Medina) — Mon, 06 Oct 2008 19:21:00 +0000

Check out the 8-minute Brain Rules podcast at BNET.com

Other News:

Brain Rules Book Group in Second Life - a weekly (every Monday) gathering for the month of October

Boing Boing review

Painting Neural Circuitry With a Viral Brush

noreply@blogger.com (John Medina) — Mon, 29 Sep 2008 20:45:00 +0000

The "Molecules of the Mind" column appears monthly in the Psychiatric Times. Learn more about "Brain Rules" at www.brainrules.net.

We often describe neural connections in the brain as if they were a cellular version of Michelangelo’s famous painting “Hand of God Giving Life to Adam,” on the ceiling of the Sistine Chapel. Like the painting, the neural explanations usually invoke 2 outstretched limbs nearly touching each other—one presynaptic,one postsynaptic—that are separated by their 20-nanometer synaptic cleft.

Such descriptions hardly depict the neurological reality of the brain, of course. A better metaphor for 2 neurons might be 2 trees that have been uprooted and turned 90 degrees so their root systems face each other. Then, some Paul Bunyan–type character jams both ends together. Thousands of connections from 1 tree now face thousands of connections from the other. Multiply those 2 neurons by thousands while all their root systems are still jammed together with the same Bunyanesque enthusiasm and you can visualize an approximation of the real world of brain wiring. Not as elegant as 2 limbs—and not as simple either.

How can we understand the way all those myriad connections work together to produce the various neurological abilities of the brain? Given its complexity, the task is enormous. Since we are only in the initial stages, it will take a long time before we will be able to map structure to function.

Like any exploration in its initial stages, we first need a good map—a schematic that shows how each slender dendritic branch interacts with a specific nerve cell. From Nissl and Weigert stains to the canonical Golgi stain, we have traditionally used dye technology to help us visualize these interactions. However, there are severe limitations to most of these staining technologies that center around their inability to make visible all the connections that actual neurons possess. We need something with far greater resolution and, perhaps, with a bit more elegance.

The topic of this column and the next is a technology that promises to deliver just such circuit diagrams at a very high level of resolution. The technology involves the exploration of viruses, which in their native form cause some pretty tough diseases (eg, rabies, cancer). Thoughtful genetic engineering has transformed these viruses’ job description from fearful disease inducer to doughty cartographer cartographer. We are going to follow how this transformation has occurred.

Download the full column (PDF), which appears in the October issue of Psychiatric Times.

Blood Tests for Bipolar I Disorder

noreply@blogger.com (John Medina) — Wed, 03 Sep 2008 20:45:00 +0000

I experienced an interesting confluence of events the other day. My 11-year-old son has been finding out about the great power of online information. Although we limit his access to assistance with homework, he is already a digital whiz kid who knows where to find a great deal of information for writing tomes like Norse history reports. In my day, it would have taken an entire afternoon of digging through texts at a university library to obtain items he found in a few seconds.

The confluence came about because of what I was doing while sitting next to him. While he was busy downloading information about Vikings, I was reading an update on a story that I have been following for a few years: the attempt to create a simple, objective blood test that could properly identify mood disorders. That would be a truly handy gadget for mental health professionals to have in their diagnostic tool kits! Going through the literature, which relies heavily on gene expression data, it hit me how profoundly the judicious use of online databases has contributed to the scientific rigor of the research. The Internet was not only seminal to my son’s work but also to this blood test research.

In this column, I will discuss new progress on this Internet-boosted line of inquiry. I will begin with a few basics about differential gene expression and microarrays and will then move on to something that researchers are calling “convergent functional genomics.” As you shall see, the clever use of online databases both confirmed and extended the work done at the bench. As a result, it may very well be possible in the next few years to have a clinic-ready blood test that is capable of diagnosing unipolar and bipolar depression. There may even be a diagnostic test for schizophrenia.

Download the column (PDF), which appears in the September issue of Psychiatric Times.

Oxytocin and the Bottom Line

noreply@blogger.com (John Medina) — Tue, 12 Aug 2008 22:25:00 +0000

Trust can be a scary proposition. Among other characteristics, trusting someone involves the ability to measurably predict a behavior on the basis of nothing more than a memory, an impression, or a whim. For creatures like us, who spend a ridiculous amount of time with unpredictable strangers, brokering trust is an oddly important survival strategy.

Trusting behaviors have fascinated a broad swath of the behavioral research community, from social scientists and evolutionary theorists to cellular and molecular biologists. This community has, over the past few years, acquired insight from unlikely corners of academia, including, of all places, business schools. This column is all about an interesting collision between biologists, economists, and the human capacity to rely on the character or integrity of other people.

Those of you who are already familiar with the topic know I am about to discuss one of biology’s most ancient neurotransmitters: oxytocin. Its molecular mechanisms have become increasingly well characterized and have strong links to behaviors that involve the seemingly subjective experience of trust. Oxytocin has even been hypothesized to influence economic decisions. Can it?

To read the rest of the column, download the PDF (it's too long to post on the blog). "Oxytocin and the Bottom Line" was published in the August issue of Psychiatric Times. You can download all the 2008 "Molecules of the Mind" columns below or here.

Oxytocin and the Bottom Line (August 2008)

Of Stress and Alcoholism, Of Mice and Men (July 2008)

The Biology of Recognition Memory (June 2008)

Why Emotional Memories Are Unforgettable (May 2008)

Schizophrenia, DISC1, and Animal Models (April 2008)

Neurobiology of PTSD—Part 3 (March 2008)

Neurobiology of PTSD—Part 2 (February 2008)

Neurobiology of PTSD—Part 1 (January 2008)

Repeat to Remember, Remember to Repeat

noreply@blogger.com (John Medina) — Fri, 11 Jul 2008 17:42:00 +0000

It takes years to consolidate a memory. Not minutes, hours, or days but years. What you learn in first grade is not completely formed until your sophomore year in high school.

Watch John Medina explain how long-term memory works. View on YouTube.

BRAIN RULE RUNDOWN
Rule #5: Repeat to remember

The human brain can only hold about seven pieces of information for less than 30 seconds! Which means, your brain can only handle a 7-digit phone number. If you want to extend the 30 seconds to a few minutes or even an hour or two, you will need to consistently re-expose yourself to the information. Memories are so volatile that you have to repeat to remember.
Improve your memory by elaborately encoding it during its initial moments. Many of us have trouble remembering names. If at a party you need help remembering Mary, it helps to repeat internally more information about her. “Mary is wearing a blue dress and my favorite color is blue.” It may seem counterintuitive at first but study after study shows it improves your memory.
Brain Rules in the classroom. In partnership with the University of Washington and Seattle Pacific University, Medina tested this Brain Rule in real classrooms of 3rd graders. They were asked to repeat their multiplication tables in the afternoons. The classrooms in the study did significantly better than the classrooms that did not have the repetition. If brain scientists get together with teachers and do research, we may be able to eliminate need for homework since learning would take place at school, instead of the home.

More Resources
->Short-term memory tutorial (Brain Rule #5)
->Short-term memory references (PDF)
->Long-term memory tutorial (Brain Rule #6)
->Long-term memory references (PDF)

Hang Up and Drive

noreply@blogger.com (John Medina) — Fri, 06 Jun 2008 05:42:00 +0000

View the 2-minute "Hang Up and Drive" video on YouTube. Driving while talking on a cell phone is like driving drunk.

Brain Rules for PowerPoint & Keynote presenters

noreply@blogger.com (John Medina) — Tue, 20 May 2008 16:54:00 +0000

Garr Reynolds, author of "Presenation Zen," has a great post on his blog discussing the book: Brain Rules for PowerPoint & Keynote presenters.

Here's what Garr says about the book:

"Brain Rules is one of the most informative, engaging, and useful books of our time. Required reading for every educator and every business person. My favorite book of 2008!"

View Upload your own

Above: here's a slide presentation Garr created based on some of the ideas in Brain Rules.

Brain Rules Webinar - Tuesday, June 3 at 2pm EDT/11am PDT

noreply@blogger.com (John Medina) — Tue, 13 May 2008 18:28:00 +0000

Join John Medina for a live Brain Rules Webinar covering Exercise, Stress, and Multitasking. The free Webinar is hosted by Alvaro Fernandez, the co-founder of SharpBrains.

Date and time: Tuesday, June 3 at 2pm EDT/11am PDT
Register: Here

SharpBrains Blog Post
Brain Rules