Deric Bownds' MindBlog

Like us, monkeys don't like computer faces that are 'too real'.

mdbownds@wisc.edu (Deric Bownds) — Fri, 06 Nov 2009 10:35:00 +0000

Synthetic agents such as androids or computer-animated characters can elicit responses from us (mainly of positive emotional valence) similar to those elicited by real humans as long as they have a low resemblance to humans. But, if these agents become too realistic, we find them unsettling. This feeling of eeriness is known as the “uncanny valley” and is associated with entities that elicit the concept of a human, but do meet all of the requirements for being one. Steckenfinger and Ghazanfar find that monkeys apparently have the same kind of response.

Very realistic human-looking robots or computer avatars tend to elicit negative feelings in human observers. This phenomenon is known as the “uncanny valley” response. It is hypothesized that this uncanny feeling is because the realistic synthetic characters elicit the concept of “human,” but fail to live up to it. That is, this failure generates feelings of unease due to character traits falling outside the expected spectrum of everyday social experience. These unsettling emotions are thought to have an evolutionary origin, but tests of this hypothesis have not been forthcoming. To bridge this gap, we presented monkeys with unrealistic and realistic synthetic monkey faces, as well as real monkey faces, and measured whether they preferred looking at one type versus the others (using looking time as a measure of preference). To our surprise, monkey visual behavior fell into the uncanny valley: They looked longer at real faces and unrealistic synthetic faces than at realistic synthetic faces.

Our left and right hemispheres can selectively track expected value

mdbownds@wisc.edu (Deric Bownds) — Fri, 06 Nov 2009 10:30:00 +0000

Palminteri et al. show that the expected values of two options, which were cued by visual symbols and chosen with either the left or right hand, enhanced activity, respectively, in the right or left (i.e. contralateral) ventral prefrontal cortex, thus respecting the topography of the brain systems elicited by the available options.

A main focus in economics is on binary choice situations, in which human agents have to choose between two alternative options. The classical view is that decision making consists of valuating each option, comparing the two expected values, and selecting the higher one. Some neural correlates of option values have been described in animals, but little is known about how they are represented in the human brain: are they integrated into a single center or distributed over different areas? To address this issue, we examined whether the expected values of two options, which were cued by visual symbols and chosen with either the left or right hand, could be distinguished using functional magnetic resonance imaging. The two options were linked to monetary rewards through probabilistic contingencies that subjects had to learn so as to maximize payoff. Learning curves were fitted with a standard computational model that updates, on a trial-by-trial basis, the value of the chosen option in proportion to a reward prediction error. Results show that during learning, left and right option values were specifically expressed in the contralateral ventral prefrontal cortex, regardless of the upcoming choice. We therefore suggest that expected values are represented in a distributed manner that respects the topography of the brain systems elicited by the available options.

Genetic enhancement of memory.

mdbownds@wisc.edu (Deric Bownds) — Thu, 05 Nov 2009 10:35:00 +0000

Just as I was thinking about doing a post on the recent paper by Wang et al. showing improved memory performance in rats genetically engineered to over-express a subunit of a synaptic receptor gene, my son-in-law J.T. Smith pointed out a very nice summary of the work in h+ magazine.

We can generate a novel body image internally, without external feedback

mdbownds@wisc.edu (Deric Bownds) — Thu, 05 Nov 2009 10:35:00 +0000

Our body image, as well as our body's location in space, can be manipulated by altering sensory feedback from the environment. Now Moseley and Brugger make the amazing observation that we can change our sense of ownership and agency to include impossible movements, independent of sensory feedback from the body or external feedback about task performance.

The feeling we have of our own body, sometimes called “body image,” is fundamental to self-awareness. However, by altering sensory input, the body image can be modified into impossible configurations. Can impossible movements of the body image be conjured solely via internally generated mechanisms, and, if so, do the structural characteristics of the body image modify to accommodate the new movements? We encouraged seven amputees with a vivid phantom arm to learn to perform a phantom wrist movement that defied normal anatomical constraints. Four reported success. Learning the impossible movement coincided in time with a profound change in the body image of the arm, including a sense of ownership and agency over a modified wrist joint. Remarkably, some previous movements and functional tasks involving the phantom arm became more difficult once the shift in body image had occurred. Crucially, these introspective reports were corroborated by robust empirical data from motor imagery tasks, about which amputees were naïve and to which assessors were blind. These results provide evidence that: a completely novel body image can be constructed solely by internally generated mechanisms; that the interdependence between movement repertoire and structural constraints of the body persists even when the structural constraints imparted by the body do not—the body image we construct still constrains imagined movements; and that motor learning does not necessarily need sensory feedback from the body or external feedback about task performance.

Social functions of gossip

mdbownds@wisc.edu (Deric Bownds) — Thu, 05 Nov 2009 10:20:00 +0000

John Tierney does a nice piece on one sort of contemporary ethnography, in this case dealing with gossip as reputational warfare.

...this time enthnographers have returned from the field with footage of a truly savage native ritual: teachers at an elementary school in the Midwest dishing about their principal behind her back.

The modern dating game.

mdbownds@wisc.edu (Deric Bownds) — Wed, 04 Nov 2009 10:35:00 +0000

Two fascinating articles (Brooks, who points to Yang) on how how technology has so fundamentally changed the ways we seek both one time and long term partners. I've tried the Grindr iPhone App described below by Yang (its GPS feature doesn't work worth diddly... it told me a handsome guy was 2,000 ft. away, and after we began to set up a meeting, he turned out to be in Iowa!). It is clear, as noted by Brooks, that all this technology "seems to threaten the sort of recurring and stable reciprocity that is the building block of trust."

So there’s this iPhone app called Grindr. It’s a GPS-enabled social-networking service for gay men. It tells you how many feet away a possible hookup is standing. Each profile comes with a picture, a tagline, the relevant stats, and a declaration of interest. You scroll through a column of heads and torsos arranged in descending order of proximity, tapping on the ones that seem promising and chatting with the ones who want the same things you do. As you make your way through the city, the menu of men reshuffles, and the erotic terrain updates in real time.

Has the search for erotic gratification ever been so efficient? Until recently, being a cad or coquette took a lot of work: You needed to buy a little black book, and you had to go around filling it, and then you had to schedule your calls for a time when the target of your seduction was likely to be at home. The less-self-assured daters in New York faced the sickening anxiety of the first phone call, or the cold approach in the bar. There were palliatives designed to help people cope—the newspaper personal ads, the paid dating services, the dirty videos and magazines—but they were generally understood to be the province of weirdos and losers.

No more. The social technologies that assist in dating and mating today are more than palliatives—they’ve changed the nature of the game. If the cold approach is more than you can deal with, put up a Craigslist ad, or join OkCupid, Manhunt, or Nerve. If the phone call makes you nervous, send a text message. And while you’re at it, send a text message to a half-dozen other people with everyone’s favorite late-night endearment: “where u at?” If nothing works out and you find yourself alone at home again, simply fire up XTube or YouPorn and choose from an endless variety of positions to help you reach a late-night climax.

Asperger's syndrome to become Autism spectrum disorder?

mdbownds@wisc.edu (Deric Bownds) — Wed, 04 Nov 2009 10:30:00 +0000

Claudia Wallis does an article on the proposal to drop the name "Asperger's syndrome,' folding it, along with the term "pervasive developmental disorder" into the term "Autism spectrum disorder." The simple fact appears to be that "nobody has been able to show consistent differences between what clinicians diagnose as Asperger’s syndrome and what they diagnose as mild autistic disorder." The not so minor problem is that the general population views "Asperger's syndrome" more positively than autism, and the term has developed its own brand identity. "The Asperger’s diagnosis is used by health insurers, researchers, state agencies and schools — not to mention people with the disorder, many of whom proudly call themselves Aspies." On the other hand Ari Ne’eman, 21 - an activist who founded the Autistic Self-Advocacy Network, a 15-chapter organization he has built while in college - notes “My identity is attached to being on the autism spectrum, not some superior Asperger’s identity. I think the consolidation to one category of autism spectrum diagnosis will lead to better services.”

The dynamics of social inequality.

mdbownds@wisc.edu (Deric Bownds) — Tue, 03 Nov 2009 11:25:00 +0000

Borgerhoff Mulder et al. show that wealth inequality in 21 historical and contemporary "small-scale societies" is determined by the intergenerational transmission of different types of assets. From the editor's summary:

Wealthy contemporary societies exhibit varying extents of economic inequality, with the Nordic countries being relatively egalitarian, whereas there is a much larger gap between top and bottom in the United States. Borgerhoff Mulder et al. build a bare-bones model describing the intergenerational transmission of three different types of wealth—based on social networks, land and livestock, and physical and cognitive capacity—in four types of small-scale societies in which livelihoods depended primarily on hunting, herding, farming, or horticulture. Parameter estimates from a large-scale analysis of historical and ethnographic data were added to the model to reveal that the four types of societies display distinctive patterns of wealth transmission and that these patterns are associated with different extents of inequality.

Here is the article abstract:

Small-scale human societies range from foraging bands with a strong egalitarian ethos to more economically stratified agrarian and pastoral societies. We explain this variation in inequality using a dynamic model in which a population’s long-run steady-state level of inequality depends on the extent to which its most important forms of wealth are transmitted within families across generations. We estimate the degree of intergenerational transmission of three different types of wealth (material, embodied, and relational), as well as the extent of wealth inequality in 21 historical and contemporary populations. We show that intergenerational transmission of wealth and wealth inequality are substantial among pastoral and small-scale agricultural societies (on a par with or even exceeding the most unequal modern industrial economies) but are limited among horticultural and foraging peoples (equivalent to the most egalitarian of modern industrial populations). Differences in the technology by which a people derive their livelihood and in the institutions and norms making up the economic system jointly contribute to this pattern.

The best way to measure brain signals...

mdbownds@wisc.edu (Deric Bownds) — Tue, 03 Nov 2009 11:15:00 +0000

Kind of a techie point, but I thought it interesting... Sirotin et al. have measured both increases in blood oxygenation and blood volume in the brains of two macaques while they performed a visual task. They find that blood-volume change is a better signal to use in brain imaging because it seems to be more closely linked to neural activity, occurring even before changes in blood oxygenation.

Dog smarts

mdbownds@wisc.edu (Deric Bownds) — Tue, 03 Nov 2009 11:10:00 +0000

An engaging article on dog intelligence in Sunday's New York Times. And on the subject of dog smarts, a new and engaging book: Darwin's Dogs: How Darwin's Pets Helped Form a World-Changing Theory of Evolution (Frances Lincoln: 2009), by Emma Townshend.

Wicked Manors....

mdbownds@wisc.edu (Deric Bownds) — Mon, 02 Nov 2009 11:40:00 +0000

I arrived at MindBlog's winter home in the Wilton Manors section of Fort Lauderdale just in time for Halloween. The photos (the one on the left being "Bride of Frankenstein with bride's maids") are from the Halloween street festival "Wicked Manors" held on the main street Wilton Drive, which is lined by gay bars and restaurants.

Prosociality in large human groups more likely due to culture than to genetics.

mdbownds@wisc.edu (Deric Bownds) — Mon, 02 Nov 2009 11:30:00 +0000

Bell et al. think about whether human prosocial behaviors such as food sharing, taxation, and warfare - nearly completely absent in other vertebrates - are more plausibly explained as arising from to cultural or genetic selection during competition among large groups. They use the term "group-level selection" to refer to the scenario in which groups differ in the frequency of individuals who are willing to sacrifice their own labor, time, or safety in ways that promote the competitive ability of the residential group, so that over time groups with higher frequencies of such “altruists” may tend to replace groups with fewer. A key point is that:

Selection for culturally-prescribed altruists occurs through the same process as for genes: groups of altruists leave more daughter societies. However, one advantage that cultural variation has over genetic is that it does not require violent inter-group competition, nor group extinctions. If failed groups were incorporated routinely into successful ones, conformist transmission and other forms of resocialization of failed groups can lead to effective cultural selection on groups even though such a pattern will generate rates of migration that keep genetic F_ST (a measure of genetic differentiation between populations) very low between neighbors. Thus selection on culture can be powerful precisely when genetic selection at the group level is weakest.

The meat of the article is formal calculation using the Price equation (don't ask...) that suggests much greater scope for cultural rather than genetic group-level selection in allowing altruism to arise.

A drug that protects prefrontal cortex from stress.

mdbownds@wisc.edu (Deric Bownds) — Mon, 02 Nov 2009 11:20:00 +0000

Here is an interesting piece from Hains et al. on stress and the prefrontal cortex. They use a rat model and a restraint stress paradigm to show that a drug can inhibit the working memory impairment and degenerative architectural changes caused by the stress.

The prefrontal cortex regulates behavior, cognition, and emotion by using working memory. Prefrontal functions are impaired by stress exposure. Acute, stress-induced deficits arise from excessive protein kinase C (PKC) signaling, which diminishes prefrontal neuronal firing. Chronic stress additionally produces architectural changes, reducing dendritic complexity and spine density of cortico-cortical pyramidal neurons, thereby disrupting excitatory working memory networks. In vitro studies have found that sustained PKC activity leads to spine loss from hippocampal-cultured neurons, suggesting that PKC may contribute to spine loss during chronic stress exposure. The present study tested whether inhibition of PKC with chelerythrine before daily stress would protect prefrontal spines and working memory. We found that inhibition of PKC rescued working memory impairments and reversed distal apical dendritic spine loss in layer II/III pyramidal neurons of rat prelimbic cortex. Greater spine density predicted better cognitive performance, the first direct correlation between pyramidal cell structure and working memory abilities. These findings suggest that PKC inhibitors may be neuroprotective in disorders with dysregulated PKC signaling such as bipolar disorder, schizophrenia, post-traumatic stress disorder, and lead poisoning—conditions characterized by impoverished prefrontal structural and functional integrity.

Extroverts and introverts

mdbownds@wisc.edu (Deric Bownds) — Thu, 29 Oct 2009 10:30:00 +0000

I couldn't resist passing this on from the I CAN HAS CHEEZ BURGER site:

The brain's anatomy of emotion induced by music.

mdbownds@wisc.edu (Deric Bownds) — Thu, 29 Oct 2009 10:25:00 +0000

From Tranel, Adolphs, and collaborators, a fascinating piece of work reported in the International Journal of Psychology (check out the other articles in this issue, which has the theme 'Central and peripheral nervous system interactions: From mind to brain to body' Here is the abstract from their paper, followed by one table:

Does feeling an emotion require changes in autonomic responses, as William James proposed? Can feelings and autonomic responses be dissociated? Findings from cognitive neuroscience have identified brain structures that subserve feelings and autonomic response, including those induced by emotional music. In the study reported here, we explored whether feelings and autonomic responses can be dissociated by using music, a stimulus that has a strong capacity to induce emotional experiences. We tested two brain regions predicted to be differentially involved in autonomic responsivity (the ventromedial prefrontal cortex) and feeling (the right somatosensory cortex). Patients with damage to the ventromedial prefrontal cortex were impaired in their ability to generate skin-conductance responses to music, but generated normal judgments of their subjective feelings in response to music. Conversely, patients with damage to the right somatosensory cortex were impaired in their self-rated feelings in response to music, but generated normal skin-conductance responses to music. Control tasks suggested that neither impairment was due to basic defects in hearing the music or in cognitively recognizing the intended emotion of the music. The findings provide evidence for a double dissociation between feeling emotions and autonomic responses to emotions, in response to music stimuli.

I thought the music clips they used to elicit emotional responses were interesting (click to enlarge):

By the way, here is another recent article by Salimpoor et al. on emotional arousal caused by music.

Dopamine, a molecule of motivation

mdbownds@wisc.edu (Deric Bownds) — Thu, 29 Oct 2009 10:15:00 +0000

Angier does a summary.

MindBlog on the road.

mdbownds@wisc.edu (Deric Bownds) — Wed, 28 Oct 2009 10:45:00 +0000

Over the past month of unseasonably cold weather here in Middleton Wisconsin my movement has become increasingly stiff and arthritic, so today I am loading up the car and driving with my two abyssinian cats to Fort Lauderdale for the winter, unable to predict the frequency of posts for the next few days. The picture shows a Maple tree in my front yard.

A jaded view....

mdbownds@wisc.edu (Deric Bownds) — Wed, 28 Oct 2009 10:15:00 +0000

A less positive view of humankind than the one described in the previous post - from the Oct. 26 issue of The New Yorker. The caption: "Well, that was a waste of time." :

Nature's lessons for a more kind society.

mdbownds@wisc.edu (Deric Bownds) — Wed, 28 Oct 2009 10:00:00 +0000

Blog reader Gary Olson has pointed me to his review of Franz De Waal's new book
"The Age of Empathy: Nature’s Lessons For A Kinder Society." From that review:

de Waal provides compelling support for the proposition that humans are “preprogrammed to reach out.” From dolphins ferrying injured companions to safety and grieving elephants, baboons and cats (yes, even cats) to commiserating mice and hydrophobic chimps risking death to save a drowning companion, this is a major contribution to understanding the biological genesis of our inborn capacity for empathy, hence morality.

In seven crisply written and wholly accessible chapters de Waal methodically demolishes the rationale behind Gordon Gekko’s admonition in the film "Wall Street" that greed “captures the essence of the evolutionary spirit.”...De Waal objects to an unrestrained market system, not capitalism itself. He prefers that the economic system be mitigated by more attention to empathy in order to soften its rough edges...Nevertheless, de Waal seriously underestimates certain capitalist imperatives and the role played by elites in cultivating callousness, thereby undermining social solidarity, reciprocity and empathy. Capitalist culture devalues an empathic disposition, and, as Erich Fromm argued some fifty years ago, there is a basic incompatibility between the underlying principles of capitalism and the lived expression of an ethos of empathy.

Learning sculpts our spontaneous resting brain activity.

mdbownds@wisc.edu (Deric Bownds) — Tue, 27 Oct 2009 10:35:00 +0000

Lewis et al. have demonstrated that learning an attention-demanding visual task modifies the spontaneous correlation of activity in the resting human brain - suggesting that the functional architecture of the brain is partly a product of previous experience. At left is a clay model representation of the human brain provided by Lewis, colored to indicate putative areas in frontal, temporal, and parietal cortex changed by a task. The abstract:

The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal representations, although its functional role is not well understood. One spontaneous signal being intensely investigated in the human brain is the interregional temporal correlation of the blood-oxygen level-dependent (BOLD) signal recorded at rest by functional MRI (functional connectivity-by-MRI, fcMRI, or BOLD connectivity). This signal is intrinsic and coherent within a number of distributed networks whose topography closely resembles that of functional networks recruited during tasks. While it is apparent that fcMRI networks reflect anatomical connectivity, it is less clear whether they have any dynamic functional importance. Here, we demonstrate that visual perceptual learning, an example of adult neural plasticity, modifies the resting covariance structure of spontaneous activity between networks engaged by the task. Specifically, after intense training on a shape-identification task constrained to one visual quadrant, resting BOLD functional connectivity and directed mutual interaction between trained visual cortex and frontal-parietal areas involved in the control of spatial attention were significantly modified. Critically, these changes correlated with the degree of perceptual learning. We conclude that functional connectivity serves a dynamic role in brain function, supporting the consolidation of previous experience.

Monkeys drumming - a gestural origin of speech and music?

mdbownds@wisc.edu (Deric Bownds) — Tue, 27 Oct 2009 10:30:00 +0000

From Remediosa, Logothetisa, and Kaysera:

Salient sounds such as those created by drumming can serve as means of nonvocal acoustic communication in addition to vocal sounds. Despite the ubiquity of drumming across human cultures, its origins and the brain regions specialized in processing such signals remain unexplored. Here, we report that an important animal model for vocal communication, the macaque monkey, also displays drumming behavior, and we exploit this finding to show that vocal and nonvocal communication sounds are represented by overlapping networks in the brain's temporal lobe. Observing social macaque groups, we found that these animals use artificial objects to produce salient periodic sounds, similar to acoustic gestures. Behavioral tests confirmed that these drumming sounds attract the attention of listening monkeys similarly as conspecific vocalizations. Furthermore, in a preferential looking experiment, drumming sounds influenced the way monkeys viewed their conspecifics, suggesting that drumming serves as a multimodal signal of social dominance. Finally, by using high-resolution functional imaging we identified those brain regions preferentially activated by drumming sounds or by vocalizations and found that the representations of both these communication sounds overlap in caudal auditory cortex and the amygdala. The similar behavioral responses to drumming and vocal sounds, and their shared neural representation, suggest a common origin of primate vocal and nonvocal communication systems and support the notion of a gestural origin of speech and music.

Characteristics of drumming sounds. (A) In this example, a macaque drums by firmly grasping the cage door with his forelimbs and shaking it vigorously and repeatedly. The inset displays the typical facial expression during drumming: open-mouth threatening, staring, forward directed pinnae. (B) Drumming sounds are acoustically distinct from typical vocalizations such as screams, grunts, or pant-threats. The repetitive beat pattern of the drumming sound produced by this action is visible in the time-frequency spectrum. The black line displays the power spectrum.

Meditation training can enhance the stability of our attention

mdbownds@wisc.edu (Deric Bownds) — Mon, 26 Oct 2009 10:30:00 +0000

Several groups collaborate to show that meditation training can can significantly affect attention and brain function.

The capacity to stabilize the content of attention over time varies among individuals, and its impairment is a hallmark of several mental illnesses. Impairments in sustained attention in patients with attention disorders have been associated with increased trial-to-trial variability in reaction time and event-related potential deficits during attention tasks. At present, it is unclear whether the ability to sustain attention and its underlying brain circuitry are transformable through training. Here, we show, with dichotic listening task performance and electroencephalography, that training attention, as cultivated by meditation, can improve the ability to sustain attention. Three months of intensive meditation training reduced variability in attentional processing of target tones, as indicated by both enhanced theta-band phase consistency of oscillatory neural responses over anterior brain areas and reduced reaction time variability. Furthermore, those individuals who showed the greatest increase in neural response consistency showed the largest decrease in behavioral response variability. Notably, we also observed reduced variability in neural processing, in particular in low-frequency bands, regardless of whether the deviant tone was attended or unattended. Focused attention meditation may thus affect both distracter and target processing, perhaps by enhancing entrainment of neuronal oscillations to sensory input rhythms, a mechanism important for controlling the content of attention. These novel findings highlight the mechanisms underlying focused attention meditation and support the notion that mental training can significantly affect attention and brain function.

Election night 2008: testosterone level of male McCain voters dropped

mdbownds@wisc.edu (Deric Bownds) — Mon, 26 Oct 2009 10:15:00 +0000

Stanton et al. collected saliva samples from 183 study participants before and after the results of the 2008 presidential election were announced. The results show that male Barack Obama voters (winners) had stable post-outcome testosterone levels, whereas testosterone levels dropped in male John McCain and Robert Barr (Libertarian candidate) voters (losers). There were no significant effects in female voters. These results were consistent with earlier studies showing testosterone decreases in male supporters of an athletic team after it loses a game.

Emotional contagion without conscious awareness

mdbownds@wisc.edu (Deric Bownds) — Fri, 23 Oct 2009 10:45:00 +0000

Tamietto et al. make the fascinating observation that unseen emotionally expressive facial or body movements (stimuli presented to the blind portion of the visual field of patients with damage to their visual cortex) cause arousal and facial reactions. They suggest that emotional contagion represents affective reactions mediated by visual pathways of old evolutionary origin that bypass cortical vision and allow emotion communication and affect sharing. Here is their abstract:

The spontaneous tendency to synchronize our facial expressions with those of others is often termed emotional contagion. It is unclear, however, whether emotional contagion depends on visual awareness of the eliciting stimulus and which processes underlie the unfolding of expressive reactions in the observer. It has been suggested either that emotional contagion is driven by motor imitation (i.e., mimicry), or that it is one observable aspect of the emotional state arising when we see the corresponding emotion in others. Emotional contagion reactions to different classes of consciously seen and “unseen” stimuli were compared by presenting pictures of facial or bodily expressions either to the intact or blind visual field of two patients with unilateral destruction of the visual cortex and ensuing phenomenal blindness. Facial reactions were recorded using electromyography, and arousal responses were measured with pupil dilatation. Passive exposure to unseen expressions evoked faster facial reactions and higher arousal compared with seen stimuli, therefore indicating that emotional contagion occurs also when the triggering stimulus cannot be consciously perceived because of cortical blindness. Furthermore, stimuli that are very different in their visual characteristics, such as facial and bodily gestures, induced highly similar expressive responses. This shows that the patients did not simply imitate the motor pattern observed in the stimuli, but resonated to their affective meaning. Emotional contagion thus represents an instance of truly affective reactions that may be mediated by visual pathways of old evolutionary origin bypassing cortical vision while still providing a cornerstone for emotion communication and affect sharing.

Health improves during economic depressions.

mdbownds@wisc.edu (Deric Bownds) — Fri, 23 Oct 2009 10:30:00 +0000

Having to live more lean and mean in economically hard times is apparently good for us. From Granados and Roux:

Recent events highlight the importance of examining the impact of economic downturns on population health. The Great Depression of the 1930s was the most important economic downturn in the U.S. in the twentieth century. We used historical life expectancy and mortality data to examine associations of economic growth with population health for the period 1920–1940. We conducted descriptive analyses of trends and examined associations between annual changes in health indicators and annual changes in economic activity using correlations and regression models. Population health did not decline and indeed generally improved during the 4 years of the Great Depression, 1930–1933, with mortality decreasing for almost all ages, and life expectancy increasing by several years in males, females, whites, and nonwhites. For most age groups, mortality tended to peak during years of strong economic expansion (such as 1923, 1926, 1929, and 1936–1937). In contrast, the recessions of 1921, 1930–1933, and 1938 coincided with declines in mortality and gains in life expectancy. The only exception was suicide mortality which increased during the Great Depression, but accounted for less than 2% of deaths. Correlation and regression analyses confirmed a significant negative effect of economic expansions on health gains. The evolution of population health during the years 1920–1940 confirms the counterintuitive hypothesis that, as in other historical periods and market economies, population health tends to evolve better during recessions than in expansions.