Delusions of Gender.

Katherine Bouton reviews what looks like a very interesting book by cognitive neuroscientist Cordelia Fine which has the title of this post. The book:

takes on that tricky question, Why exactly are men from Mars and women from Venus?, and eviscerates both the neuroscientists who claim to have found the answers and the popularizers who take their findings and run with them...Summarizing the research, she writes, “Nonexistent sex differences in language lateralization, mediated by nonexistent sex differences in corpus callosum structure, are widely believed to explain nonexistent sex differences in language skills.”...What all this adds up to, she says, is neurosexism. It’s all in the brain....But Dr. Fine persuasively argues that it is, in fact, all in the mind. Jan Morris, the historian, travel writer and male-to-female transsexual, saw this implicit stereotyping firsthand: “The more I was treated as a woman, the more woman I became. ”

Metacognitive deficits in public political discourse

Some interesting chunks from a recent David Brooks column in the NYTimes, on what he takes to be the underlying problem facing this country. He starts by describing the decay in the 19th and early 20th century emphasis on moral character,

...when people were more conscious of the fallen nature of men and women. People were held to be inherently sinful, and to be a decent person one had to struggle against one’s weakness...This emphasis on mental character lasted for a time, but it has abated. There’s less talk of sin and frailty these days...In the media competition for eyeballs, everyone is rewarded for producing enjoyable and affirming content. Output is measured by ratings and page views, so much of the media, and even the academy, is more geared toward pleasuring consumers, not putting them on some arduous character-building regime.

...we’re all less conscious of our severe mental shortcomings and less inclined to be skeptical of our own opinions...We have confirmation bias; we pick out evidence that supports our views. We are cognitive misers; we try to think as little as possible. We are herd thinkers and conform our perceptions to fit in with the group...The ensuing mental flabbiness is most evident in politics. Many conservatives declare that Barack Obama is a Muslim because it feels so good to say so...a seller’s market in ideologies...gives people a chance to feel victimized. There’s a rigidity to political debate. Issues like tax cuts and the size of government, which should be shaped by circumstances (often it’s good to cut taxes; sometimes it’s necessary to raise them), are now treated as inflexible tests of tribal purity.

To use a fancy word, there’s a metacognition deficit. Very few in public life habitually step back and think about the weakness in their own thinking and what they should do to compensate.

Inflammatory and neural responses to social rejection.

Slavich et al. measure changes in both brain activity and inflammatory chemical activity in response to social rejection:

Although stress-induced increases in inflammation have been implicated in several major disorders, including cardiovascular disease and depression, the neurocognitive pathways that underlie inflammatory responses to stress remain largely unknown. To examine these processes, we recruited 124 healthy young adult participants to complete a laboratory-based social stressor while markers of inflammatory activity were obtained from oral fluids. A subset of participants (n = 31) later completed an fMRI session in which their neural responses to social rejection were assessed. As predicted, exposure to the laboratory-based social stressor was associated with significant increases in two markers of inflammatory activity, namely a soluble receptor for tumor necrosis factor-α (sTNFαRII) and interleukin-6 (IL-6). In the neuroimaging subsample, greater increases in sTNFαRII (but not IL-6) were associated with greater activity in the dorsal anterior cingulate cortex and anterior insula, brain regions that have previously been associated with processing rejection-related distress and negative affect. These data thus elucidate a neurocognitive pathway that may be involved in potentiated inflammatory responses to acute social stress. As such, they have implications for understanding how social stressors may promote susceptibility to diseases with an inflammatory component.

The psychology of possibility.

An interesting article in the Harvard Magazine describes the life work of Ellen Langer, her demonstrations that our social self image (old versus young, for example) strongly patterns our actual vitality and physiology, her work on Mindfulness, unconscious processing, etc. I recommend that you read the article. Here are some clips from its beginning that hooked me (I actually did my own mini-repeat of the experiment described, a simple self-experiment of pretending that I had been transported back in time to 40 years ago, and convinced myself I was experiencing some of the effects described)...

In 1981, early in her career at Harvard, Ellen Langer and her colleagues piled two groups of men in their seventies and eighties into vans, drove them two hours north to a sprawling old monastery in New Hampshire, and dropped them off 22 years earlier, in 1959. The group who went first stayed for one week and were asked to pretend they were young men, once again living in the 1950s. The second group, who arrived the week afterward, were told to stay in the present and simply reminisce about that era. Both groups were surrounded by mid-century mementos—1950s issues of Life magazine and the Saturday Evening Post, a black-and-white television, a vintage radio—and they discussed the events of the time: the launch of the first U.S. satellite, Castro’s victory ride into Havana, Nikita Khrushchev and the need for bomb shelters.

...Before and after the experiment, both groups of men took a battery of cognitive and physical tests, and after just one week, there were dramatic positive changes across the board. Both groups were stronger and more flexible. Height, weight, gait, posture, hearing, vision—even their performance on intelligence tests had improved. Their joints were more flexible, their shoulders wider, their fingers not only more agile, but longer and less gnarled by arthritis. But the men who had acted as if they were actually back in 1959 showed significantly more improvement. Those who had impersonated younger men seemed to have bodies that actually were younger.

Delaying age-related damange to nerves and muscle

Both exercise and drastic dieting have been shown to have anti-ageing effects in the brain. Studies on mice now suggest that such lifestyle changes preserve communication between nerves and muscles:

The cellular basis of age-related behavioral decline remains obscure but alterations in synapses are likely candidates. Accordingly, the beneficial effects on neural function of caloric restriction and exercise, which are among the most effective anti-aging treatments known, might also be mediated by synapses. As a starting point in testing these ideas, we studied the skeletal neuromuscular junction (NMJ), a large, accessible peripheral synapse. Comparison of NMJs in young adult and aged mice revealed a variety of age-related structural alterations, including axonal swellings, sprouting, synaptic detachment, partial or complete withdrawal of axons from some postsynaptic sites, and fragmentation of the postsynaptic specialization. Alterations were significant by 18 mo of age and severe by 24 mo. A life-long calorie-restricted diet significantly decreased the incidence of pre- and postsynaptic abnormalities in 24-mo-old mice and attenuated age-related loss of motor neurons and turnover of muscle fibers. One month of exercise (wheel running) in 22-mo-old mice also reduced age-related synaptic changes but had no effect on motor neuron number or muscle fiber turnover. Time-lapse imaging in vivo revealed that exercise partially reversed synaptic alterations that had already occurred. These results demonstrate a critical effect of aging on synaptic structure and provide evidence that interventions capable of extending health span and lifespan can partially reverse these age-related synaptic changes.

Predicting inherited risk for anxiety

Ned Kalin and his colleagues here at the University of Wisconsin have made the interesting observation that increased brain activity in the amygdala (not inheritable) and anterior hippocampus (inheritable) of young monkeys can predict anxious temperament in young monkeys, leading Kalin to suggest that "that young children who have higher activity in these brain regions are more likely to develop anxiety and depression as adolescents and adults, and are also more likely to develop drug and alcohol problems in an attempt to treat their distress." The study looked at 238 young rhesus monkeys from a family of more than 1500 lab-raised monkeys with well-documented pedigrees. By analyzing the family connections among the young monkeys, which ranged from siblings to distant cousins, the finding was that an anxious temperament was partly heritable, accounting for about 36% of the variability in individual monkeys' responses on a human intruder test (as measured by the reduction in movement and vocalization and increase in stress hormone levels). Elevated responses in the hippocampus were heritable (accounting for about half of individual variability), whereas the elevated responses in the amygdala were not.

Figure from paper - Anxious monkeys show elevated activity in the amygdala (left) and anterior hippocampus (right), but the effects of heredity seem to act more on the hippocampus.

Oxytocin makes people trusting, but not gullible.

Mikolajczak et al. demonstrate that oxytocin (OT) is not the magical “trust elixir” described in the news, on the Internet, or even by some influential researchers. They design experiments to show that it does not make people indiscriminately prosocial (trusting to a fault). They used a customized version of the trust game that manipulated partners’ trustworthiness and measured participants’ investment in each partner. They found higher investment by participants who received a nasal OT spray than by control participants, unless there were cues that a partner might not be trustworthy. They also observed a significant effect of OT when the partner was a computer suggesting that OT’s effect may be primarily moderated not by the human versus nonhuman nature of the partner, but rather by the perceived risk inherent to the interaction. In case you are interested, here is their description of the setup:

Each participant assumed the role of investor and could transfer money to a “trustee,” in whose hands the funds would triple. The trustee would then transfer all the money, part of it, or none of it back to the investor. If the investor entrusted the trustee with all of his money, he could maximize his profits if the trustee was reliable and fair. Conversely, he could lose everything if the trustee was not fair. The trust game is perfectly suited to establish the investor’s level of trust (i.e., the higher the trust, the higher the transfer). Each participant played with three different types of trustees: seemingly reliable humans, seemingly unreliable humans, and the computer (i.e., a fully neutral device). By manipulating the partners’ trustworthiness, we sought to determine the extent to which OT impairs sensitivity to potential signs of dishonesty.

In one part of the game, participants were told that they would play 10 rounds with the computer, which would randomly determine the back transfers; in another part, participants were told that they would play online with real people. We gave participants a brief description of their partner before each round. Based on a pretest, these descriptions were manipulated to induce high or low trust: We combined trustworthy academic fields (e.g., philosophy) and activities (e.g., practicing first aid) to make some partners seem reliable, and untrustworthy academic fields (e.g., marketing) and activities (e.g., playing violent sports) to make other partners seem unreliable. The main effect of partner type  confirms that these descriptions were effective in inducing trust or mistrust in this study. Each participant played 10 rounds with 10 different partners (5 trustworthy, 5 untrustworthy). No back-transfers feedback was provided during the experiment, and presentation order was randomized. Before leaving the laboratory, participants were asked to guess the group (OT or control) to which they had been assigned.

Coping with stress stimulates new brain cell growth.

Interesting stuff from Lyons et al., experiments on monkeys which look like they would extrapolate to us humans:

Coping with intermittent social stress is an essential aspect of living in complex social environments. Coping tends to counteract the deleterious effects of stress and is thought to induce neuroadaptations in corticolimbic brain systems. Here we test this hypothesis in adult squirrel monkey males exposed to intermittent social separations and new pair formations. These manipulations simulate conditions that typically occur in male social associations because of competition for limited access to residency in mixed-sex groups. As evidence of coping, we previously confirmed that cortisol levels initially increase and then are restored to prestress levels within several days of each separation and new pair formation. Follow-up studies with exogenous cortisol further established that feedback regulation of the hypothalamic-pituitary-adrenal axis is not impaired. Now we report that exposure to intermittent social separations and new pair formations increased hippocampal neurogenesis in squirrel monkey males. Hippocampal neurogenesis in rodents contributes to spatial learning performance, and in monkeys we found that spatial learning was enhanced in conditions that increased hippocampal neurogenesis. Corresponding changes were discerned in the expression of genes involved in survival and integration of adult-born granule cells into hippocampal neural circuits. These findings support recent indications that stress coping stimulates hippocampal neurogenesis in adult rodents. Psychotherapies designed to promote stress coping potentially have similar effects in humans with major depression.

Solving protein folding - humans outperform computers

I remember from my graduate student days in the 1960's attending biochemistry lectures in which the professors expressed confidence that we would soon know the algorithms for predicting from the linear sequence of amino acids in a protein the three dimensional shape into which it would fold. That goal has seemed to recede from view despite increasing effort with sophisticated supercomputers. (The problem is that even a moderately sized protein can theoretically fold into more possible shapes than there are particles in the universe.) It turns out that Foldit, a multiplayer online game that engages non-scientists, is now yielding more accurate predictions of correct protein folding than one of the best known computer folding programs, Rosetta@home, which was created by molecular biologist David Baker at Univ. Washington, Seattle. (The program distributes its calculations to thousands of home computers around the world, automatically sending the results back to Baker's lab.) From the abstract of the Cooper et al. paper on their Foldit game:

...top-ranked Foldit players excel at solving challenging structure refinement problems in which substantial backbone rearrangements are necessary to achieve the burial of hydrophobic residues. Players working collaboratively develop a rich assortment of new strategies and algorithms; unlike computational approaches, they explore not only the conformational space but also the space of possible search strategies. The integration of human visual problem-solving and strategy development capabilities with traditional computational algorithms through interactive multiplayer games is a powerful new approach to solving computationally-limited scientific problems.

Two useful reviews summarize this work, one in the NYTimes, the other in Science Now.

A Brahms Capriccio as a TGIF offering...

I've been lazy about playing and recording lately, and so have decided to spend a bit more time with my piano. This Brahms Capriccio has one randomly occurring error, which happens with any piece I play regardless of how well I know the notes. (I don't do the cut and paste editing of the good parts. Whatever happens on one complete play through is what you get.) See if you can find the stumble.

Watching our brains perceive the intentions of others.

Two interesting papers on  people playing economic or cooperation games during MRI imaging that reveals activations flitting about different areas of the frontal cortex as different inferences and judgments about other game participants are made:

First, from Dolan's group, on inference of belief:

Humans have the arguably unique ability to understand the mental representations of others. For success in both competitive and cooperative interactions, however, this ability must be extended to include representations of others' belief about our intentions, their model about our belief about their intentions, and so on. We developed a "stag hunt" game in which human subjects interacted with a computerized agent using different degrees of sophistication (recursive inferences) and applied an ecologically valid computational model of dynamic belief inference. We show that rostral medial prefrontal (paracingulate) cortex, a brain region consistently identified in psychological tasks requiring mentalizing, has a specific role in encoding the uncertainty of inference about the other's strategy. In contrast, dorsolateral prefrontal cortex encodes the depth of recursion of the strategy being used, an index of executive sophistication. These findings reveal putative computational representations within prefrontal cortex regions, supporting the maintenance of cooperation in complex social decision making.

The second, from Cooper et al., on judging the intentions of others:

In social decision-making, people care both about others' outcomes and their intentions to help or harm. How the brain integrates representations of others' intentions with their outcomes, however, is unknown. In this study, participants inferred others' decisions in an economic game during functional magnetic resonance imaging. When the game was described in terms of donations, ventromedial prefrontal cortex (VMPFC) activation increased for inferring generous play and decreased for inferring selfish play. When the game was described in terms of individual savings, however, VMPFC activation did not distinguish between strategies. Distinct medial prefrontal regions also encoded consistency with situational norms. A separate network, including right temporoparietal junction and parahippocampal gyrus, was more activated for inferential errors in the donation than in the savings condition. These results demonstrate that neural responses to others' generosity or selfishness depend not only on their actions but also on their perceived intentions.

Summary highlights of Cooper et al.:
- Response to others in identical economic games depends on game description
- Liking, VMPFC distinguish generous from selfish play in “group donation” game only
- Distinct MPFC regions encode consistency with norms regardless of outcome
- Right TPJ and MTL are more activated by learning errors in donation game

My hero questioned...

In this field of studying human and animal minds, I've long been in awe of the intelligence and originality of Mark Hauser. (If you enter the name Hauser in the search box in the left column of this blog you will find no fewer than 20 previous posts on his work!)  He has published crucial experiments on morality in animals, leading him to suggest a universal moral grammar analogous to Chomsky' universal language grammar, and has also reported mirror self recognition and inferring intentions of others in monkeys. His 2002 paper with Chomsky and Fitch on language evolution is a classic.

It appears now that his ambition may have outstripped his intellect. I was saddened to read this recent article in the NYTimes saying that Hauser has gone on academic leave from Harvard after an investigation by the university found problems with his research.

... his undoing seems to have been his experiments, many of which depended on videotaping cotton-topped tamarin monkeys and noting their responses. It is easy for human observers to see the response they want and so to be fooled by the monkeys.

The papers on mirror self recognition and inferring intention are particularly in question. A psychology colleague at Columbia University noted:

First there was arbitrary interpretation of the videotapes to suit the hypothesis...The other was whether the data was real. There have been a number of papers using videotape, and all of them have to be reviewed to see if the data holds up.

Paradigm change in the practice of science?

John Markoff writes an interesting article on how fundamentally critical discourse in mathematics and physics is being transformed by the web. The case in point was the claim by a researcher that he had demonstrated that P (the set of problems that can be easily solved) does not equal NP (those problems that are difficult to solve, but easy to verify once a solution is found). This inequality is fundamental to the modern cryptography required for electronic commerce and digital privacy. The proposed proof was found to have significant shortcomings within weeks, instead of the months to years required by exchanges of written papers and debate at scientific meetings, because discussion and analysis was carried out in real time on blogs and a wiki that had been quickly set up for the purpose of collectively analyzing the paper. Clay Shirky, author of “Cognitive Surplus: Creativity and Generosity in a Connected Age” argues:

....that the emergence of these new collaborative tools is paving the way for a second scientific revolution in the same way the printing press created a demarcation between the age of alchemy and the age of chemistry...a new set of norms is emerging about what it means to do mathematics, assuming coordinated participation.

Stereotypes can prevent perceptual learning.

Some interesting observations from Rydell et al, who find that simply reminding women about the negative stereotype about women's math and visual processing performance inhibits their performance on a visual search task...

Stereotype threat (ST) refers to a situation in which a member of a group fears that her or his performance will validate an existing negative performance stereotype, causing a decrease in performance. For example, reminding women of the stereotype “women are bad at math” causes them to perform more poorly on math questions from the SAT and GRE. Performance deficits can be of several types and be produced by several mechanisms. We show that ST prevents perceptual learning, defined in our task as an increasing rate of search for a target Chinese character in a display of such characters. Displays contained two or four characters and half of these contained a target. Search rate increased across a session of training for a control group of women, but not women under ST. Speeding of search is typically explained in terms of learned “popout” (automatic attraction of attention to a target). Did women under ST learn popout but fail to express it? Following training, the women were shown two colored squares and asked to choose the one with the greater color saturation. Superimposed on the squares were task-irrelevant Chinese characters. For women not trained under ST, the presence of a trained target on one square slowed responding, indicating that training had caused the learning of an attention response to targets. Women trained under ST showed no slowing, indicating that they had not learned such an attention response.

Exercise moderates anger

Tara Parker-Pope does a summary of several studies on psychological effects of exercise, which numerous studies have shown to make people (and laboratory mice) more relaxed, confident, and happy. She describes a Univ. of Georgia study showing that students with short fuses are less likely to feel anger at a provocative stimulus after exercise.

Effect of wilderness vs. tech-world on the brain

Matt Richtel describes the efforts of a group of five neuroscientists to guage the brain effects of their multitasking high tech world by taking themselves on a 5-day rafting wilderness region of the San Juan river in the Glen Canyon preserve - no email, no cell phones, no laptops, etc.

...to understand how heavy use of digital devices and other technology changes how we think and behave, and how a retreat into nature might reverse those effects.

The group contained believers (who believe in damaging psychological effects of too much digital stimulation) and skeptics (who don't). They discussed (the following is a cut/paste/edit gemash):

...a debate that has become increasingly common as technology has redefined the notion of what is “urgent.” How soon do people need to get information and respond to it? The believers in the group say the drumbeat of incoming data has created a false sense of urgency that can affect people’s ability to focus.
...a seminal study from the University of Michigan that showed people can better learn after walking in the woods than after walking a busy street...The study indicates that learning centers in the brain become taxed when asked to process information, even during the relatively passive experience of taking in an urban setting. By extension, some scientists believe heavy multitasking fatigues the brain, draining it of the ability to focus.
...Why don’t brains adapt to the heavy stimulation, turning us into ever-stronger multitaskers?..Why wouldn’t the circuits be exercised, in a sense, and we’d get stronger?
...Behavioral studies have shown that performance suffers when people multitask... researchers are wondering whether attention and focus can take a hit when people merely anticipate the arrival of more digital stimulation...The expectation of e-mail seems to be taking up our working memory...To the extent you have less working memory, you have less space for storing and integrating ideas and therefore less to do the reasoning you need to do...Working memory is a precious resource in the brain...might they be able to prove it using imaging?
...On the trip time slows down, there are periods of silence and awed looks at surroundings...The group becomes more reflective, quieter, more focused on the surroundings...even the more skeptical of the scientists say something is happening to their brains that reinforces their scientific discussions — something that could be important to helping people cope in a world of constant electronic noise...If we can find out that people are walking around fatigued and not realizing their cognitive potential...What can we do to get us back to our full potential?

"The Law of Emotional Balance?"

I thought I would pass on to readers an example of the sort of stuff that I, retired professor and minor blog writer that I am - get sent several times a weeks to "please support or link to," presumably because internet scanning algorithms point to the MindBlog site. I got hooked into spending more time on this one than I should have because the cover email was from Stephen Takowsky, publisher of The Beverly Hills Times, who had:

...come across a book about which we are considering running an article.... Your assistance would be greatly appreciated. Our main goal at this point is to determine whether there is any established scientific evidence that tends either to support or invalidate the theory presented in the book. We want to find out if there is any scientific research that is relevant to the premise of the book.

So....   I take the bait and click on http://www.ofgrandeur.com/ , find a slightly horrific graphic and an introduction on "The Law of Emotional Balance" that raises multiple red flags.   I can't get the better of my curiosity, so I click on, find "comments from active scientist in associated field" which appear to vague clips mentioning general ideas, but which do not reference this book's specific contents.  The brief introduction/preface pretty well finally cashes it in for me, and then I find the text, whose author is one Stephen Takowsky, owner and publisher of The Beverly Hills Times ("who had come across a book..", see above....must be his evil twin). He  has solicited the opinion of hundreds or academics and reports thus far that the professors' votes are 381 nay, and 253 yea...

Still, having taken as much of my time (and yours).... I click through the book and realize that any attempt to make detailed comments would be a promethean and futile task.

Seeking immortality in words, not religion

Christopher Hitchens, atheist author of "God is Not Great: How Religion Poisons Everything," is most likely dying of esophageal cancer. Liesl Schillinger writes on how his writing of an essay on his experience of illness has

...elicited hundreds of responses from well-wishers (and some foes), who urge Mr. Hitchens in online comments (and in their prayers, many write) to accept salvation...When asked, “Do you find it insulting for people to pray for you?” Mr. Hitchens responded: “No, no. I take it kindly, under the assumption that they are praying for my recovery.”..All the same, Mr. Hitchens dismissed both the notion that his cancer would lead him to make a tardy profession of faith and the idea that, if it did, such a profession would be valid...“The entity making such a remark might be a raving, terrified person whose cancer has spread to the brain,” he said. “I can’t guarantee that such an entity wouldn’t make such a ridiculous remark, but no one recognizable as myself would ever make such a remark.”

Hitchens' friend, novelist Martin Amis,

...said his friend, like other writers, surely believed that after death, “not all of you will die,” because the printed words they leave behind constitute a kind of immortality. He added, “The desire for immortality ... explains all the extraordinary achievements, both good and bad.”

Another British-born intellectual's faith in articulacy caught the public eye this summer. On Aug. 6, Tony Judt died of amyotrophic lateral sclerosis. He had told a former student

...that he wanted his epitaph to read, “I did words.”

A custody battle for the mind - brain genes from different parents

Relatively few genes (∼100) have previously been shown to be imprinted such that their expression in progeny derives from either the maternal or paternal copy. Two papers by Gregg et al. now expand this number by an order of magnitude, and reveal complex patterns of parent-of-origin bias in gene expression in the brain that are developmentally and regionally restricted, and in many cases, sexually dimorphic. They uncovered over 1300 loci with maternal or paternal allelic bias. Comparison of the parent-of-origin allelic expression bias in the adult hypothalamus and cortex, and in the developing brain, revealed spatiotemporal and sex-specific regulation. Here are a few clips from the first and the second articles:

...Many imprinted genes are expressed in neural systems associated with feeding and motivated behaviors, and parental biases preferentially target genetic pathways governing metabolism and cell adhesion. We observed a preferential maternal contribution to gene expression in the developing brain and a major paternal contribution in the adult brain. Thus, parental expression bias emerges as a major mode of epigenetic regulation in the brain.
...Our study identified preferential selection of the maternally inherited X chromosome in glutamatergic neurons of the female cortex. Moreover, analysis of the cortex and hypothalamus identified 347 autosomal genes with sex-specific imprinting features. In the hypothalamus, sex-specific imprinted genes were mostly found in females, which suggests parental influence over the hypothalamic function of daughters. We show that interleukin-18, a gene linked to diseases with sex-specific prevalence, is subject to complex, regional, and sex-specific parental effects in the brain. Parent-of-origin effects thus provide new avenues for investigation of sexual dimorphism in brain function and disease.

I found some background given in a review of this work by Tollkuhn et. al. to be useful. Some clips:

Genomic imprinting is a phenomenon in which either the maternal or paternal copy of a gene is expressed preferentially in all progeny. This curious phenomenon, which violates classical Mendelian genetics, appears to occur only in mammals among vertebrates....An imprinted gene renders the organism functionally haploid at that locus, and permits the expression of phenotypes from mutations that would normally be recessive. In other words, imprinting precludes the protection of a back-up copy afforded by a diploid genome. It has been postulated therefore that the existence of imprinting in mammals must confer a selective advantage. What this selective pressure might be remains to be settled, but the most widely accepted explanation is that imprinting is a consequence of parental conflict over resource allocation to the progeny. Briefly, it is in the father's interest to maximize maternal resources devoted to his progeny, whereas the mother might wish to allocate resources more equitably to current and future progeny, who might conceivably result from matings with other males. This conflict is particularly acute in placental mammals, in whom the progeny develop in utero and often for prolonged gestational periods, requiring greater maternal investment. As applied to imprinting, the conflict theory predicts that paternally expressed genes should increase the use of maternal resources to produce more fit offspring. By contrast, maternally expressed genes should quell the effects of such paternally expressed genes.

Where the brain stores emotional memories

The brain mechanisms involved in forming fear memories associated with smells, sounds, and visual images are fairly well understood, but where these old fear memories are stored in the brain has not been as clear. Sacco and Sacchetti now show that these fear memories are stored in secondary, but not primary, sensory cortices - depending on whether the conditioned stimulus was visual, auditory, or olfactory. Only "old," not new, memories are stored in this way, and lesions of secondary cortices, while disrupting the old memories, do not prevent the acquisition of new memories. Here is their abstract:

Visual, acoustic, and olfactory stimuli associated with a highly charged emotional situation take on the affective qualities of that situation. Where the emotional meaning of a given sensory experience is stored is a matter of debate. We found that excitotoxic lesions of auditory, visual, or olfactory secondary sensory cortices impaired remote, but not recent, fear memories in rats. Amnesia was modality-specific and not due to an interference with sensory or emotional processes. In these sites, memory persistence was dependent on ongoing protein kinase M activity and was associated with an increased activity of layers II–IV, thus suggesting a synaptic strengthening of corticocortical connections. Lesions of the same areas left intact the memory of sensory stimuli not associated with any emotional charge. We propose that secondary sensory cortices support memory storage and retrieval of sensory stimuli that have acquired a behavioral salience with the experience.

Sex at Dawn

A recent Dan Savage column in The Onion pointed me to an interesting view of our modern sexual hangups. Ryan and Jetha in their book "Sex at Dawn" ask why monogamy and infidelity are such prominent issues in many societies. They argue that monogamy does not come naturally to our species, but rather is an imposition of the religious and cultural institutions that appeared with the advent of agriculture. These institutions, together with mainstream evolutionary psychology, maintain the conventional wisdom that men and women evolved in families where a man’s possessions and protection were exchanged for a woman’s fertility and fidelity. The authors maintain that this narrative is collapsing, and take a tour of evidence from anthropology, archeology, primatology, anatomy, and psychosexuality to offer data and arguments that our ancestors lived in egalitarian groups that shared food, child care, and often, sexual partners.

I downloaded the book for my Kindle, and found it an entertaining, spirited and engaging read, although it did have its share of inaccuracies, as well as some chaotic, repetitive and preachy sections. Their argument against the conventional evolutionary psychology view as a set of just-so stories is a common one. I would suggest that you glance at the excerpts from the book offered on their website to get an idea of bouncy tone of the prose.

The first church of robotics

Technology guru Jaron Lanier has provided a lucid NYTimes Op-Ed article on now we are misguided and damaged by thinking about increasingly intelligent machines as fellow creatures rather than tools. He sees an inappropriate new religion being expressed through engineering culture, which looses sight of the fact that technology is essentially a service. You should read the article. Here are some clips:

...the nuts and bolts of A.I. research can often be more usefully interpreted without the concept of A.I. at all. For example, I.B.M. scientists recently unveiled a “question answering” machine that is designed to play the TV quiz show “Jeopardy.” Suppose I.B.M. had dispensed with the theatrics, declared it had done Google one better and come up with a new phrase-based search engine. This framing of exactly the same technology would have gained I.B.M.’s team as much (deserved) recognition as the claim of an artificial intelligence, but would also have educated the public about how such a technology might actually be used most effectively.

On Robot Teachers:

...these robots are just a form of high-tech puppetry. The children are the ones making the transaction take place — having conversations and interacting with these machines, but essentially teaching themselves. This just shows that humans are social creatures, so if a machine is presented in a social way, people will adapt to it.

On the recommendations made by Netflix and Pandora:

...our exposure to art shouldn’t be hemmed in by an algorithm that we merely want to believe predicts our tastes accurately. These algorithms do not represent emotion or meaning, only statistics and correlations...while Silicon Valley might sell artificial intelligence to consumers, our industry certainly wouldn’t apply the same automated techniques to some of its own work. Choosing design features in a new smartphone, say, is considered too consequential a game. Engineers don’t seem quite ready to believe in their smart algorithms enough to put them up against Apple’s chief executive, Steve Jobs, or some other person with a real design sensibility.

On Simgularity University:

...The influential Silicon Valley institution preaches a story that goes like this: one day in the not-so-distant future, the Internet will suddenly coalesce into a super-intelligent A.I., infinitely smarter than any of us individually and all of us combined; it will become alive in the blink of an eye, and take over the world before humans even realize what’s happening.
...a great deal of the confusion and rancor in the world today concerns tension at the boundary between religion and modernity — whether it’s the distrust among Islamic or Christian fundamentalists of the scientific worldview, or even the discomfort that often greets progress in fields like climate change science or stem-cell research...If technologists are creating their own ultramodern religion, and it is one in which people are told to wait politely as their very souls are made obsolete, we might expect further and worsening tensions. But if technology were presented without metaphysical baggage, is it possible that modernity would not make people as uncomfortable?

Finally,

Technology is essentially a form of service. We work to make the world better. Our inventions can ease burdens, reduce poverty and suffering, and sometimes even bring new forms of beauty into the world. We can give people more options to act morally, because people with medicine, housing and agriculture can more easily afford to be kind than those who are sick, cold and starving...But civility, human improvement, these are still choices. That’s why scientists and engineers should present technology in ways that don’t confound those choices...We serve people best when we keep our religious ideas out of our work.

Similar brain cortex changes during human development and evolution

Hill et al. show that expansion of the human cortex during development involves the same brain areas that have changed the most in the evolutionary expansion from monkey to human brains.  They suggest that it is beneficial for regions of recent evolutionary expansion to remain less mature at birth, perhaps to increase the influence of postnatal experience on their development.

The cerebral cortex of the human infant at term is complexly folded in a similar fashion to adult cortex but has only one third the total surface area. By comparing 12 healthy infants born at term with 12 healthy young adults, we demonstrate that postnatal cortical expansion is strikingly nonuniform: regions of lateral temporal, parietal, and frontal cortex expand nearly twice as much as other regions in the insular and medial occipital cortex. This differential postnatal expansion may reflect regional differences in the maturity of dendritic and synaptic architecture at birth and/or in the complexity of dendritic and synaptic architecture in adults. This expression may also be associated with differential sensitivity of cortical circuits to childhood experience and insults. By comparing human and macaque monkey cerebral cortex, we infer that the pattern of human evolutionary expansion is remarkably similar to the pattern of human postnatal expansion. To account for this correspondence, we hypothesize that it is beneficial for regions of recent evolutionary expansion to remain less mature at birth, perhaps to increase the influence of postnatal experience on the development of these regions or to focus prenatal resources on regions most important for early survival.

Figure - Comparison of evolutionary and postnatal cortical surface expansion. (A) Map of regional evolutionary cortical expansion between an adult macaque and the average human adult (right hemisphere only). Evolution expansion scale indicates how many times larger the surface area is in humans relative to the corresponding area in the macaque. (B) Map of human postnatal cortical expansion for comparison. (C) Correlation map comparing postnatal to evolutionary cortical surface expansion.

We generalize negative more than positive stimuli

Schechtman et al. find that our learned response to a sound frequency associated with negative reinforcement generalizes over a broader range of adjacent frequencies (has a wider generalization curve) than the response to a positive reinforcement, both being greater than the response to a neutral stimulus. This 'better be safe than sorry' strategy makes sense in terms of survival, as noted in the author's introduction. They discuss the role of the amygdala, and suggest that individual differences in the effect that emotional valence has on generalization could underlie susceptibility to long-term effects of emotional events, possibly explaining why some people seem more susceptible to post-traumatic stress disorder (PTSD).:

If you are a dog, mistaking another dog bark for a lion roar is a shame—you might have missed a friend; but mistaking a roar for a bark can be fatal...Because a miss in this example is much more "costly" than a false-alarm, a more liberal bias for the loss-related stimulus can be expected.... in real-life, it is rarely the exact specific roar or specific bark you once heard, and stimuli rarely repeat with the exact physical properties with which they were first encountered. This means that the same logic used for immediate response should generalize to similar, yet not identical, sounds. We therefore hypothesized that valence associated with a stimulus during learning would influence the scope of generalization, and specifically, that stimuli that were previously associated with loss would generalize more than stimuli that were previously associated with gain.

Here is their abstract, followed by a graphic:

Learning includes the ability to generalize to new situations and respond to similar, yet not identical stimuli. We use stimulus generalization in humans to show that tones that were negatively reinforced induce wider generalization curves than tones that were positively reinforced, and these in turn induce wider curves than neutral memory. Importantly, these wider generalization curves persist even if outcomes for all tones are made identical, indicating that the learning induced a perceptual change, and not merely a decision bias. Moreover, it persists after taking into account loss-aversion, suggesting it is a result of valence per se, and not intensity that reflects overweighting of the aversive stimuli. This effect of emotional valence on learning suggests different locations of plasticity and network mechanisms in the brain. Particularly, it suggests that brain areas that mediate reinforcement and emotions are involved during the learning process to induce a neural representation that can support this broader behavioral generalization. In addition, these findings highlight a model for anxiety and trauma disorders in which aversive experiences affect more than they should, sometimes even in seemingly irrational situations.

Figure - The amount of generalization for negative (aversive), positive (rewarding), and no (neutral)—reinforcement... Average response rate in the generalization stage for tones in different distances from the tones that were reinforced during the acquisition stage.

Trying too hard....

Here is a nice short bit from Daniel Gilbert on how trying too hard makes us perform worse.

Are self-reflective people more depressed?

I've repeatedly heard in psychology seminars the truism that introspection (versus extroversion) correlates with depression. Grossmann and Kross, in their comparison of University of Michigan and Moscow State University students, show that this depends very much on culture. Gilbert Chin does a nice summary in the July 30 Science Magazine (picture credit: Vassilij Grivorovi Perov):

Dostoyevsky. For anyone steeped in the traditional canon of Western literature, his name elicits visions of bleak winters filled with contemplative despair. This common perception of Russian culture has fueled speculation about an underlying symbiosis between a predisposition to focus on negative feelings or experiences and a tendency toward depression. Grossmann and Kross have examined this purported linkage by contrasting self-reflective measures in Russians and Americans. Brooding correlated positively with depressive symptoms in University of Michigan students, but these were inversely related in students at Moscow State University even though the latter displayed a much greater propensity for rumination. Assessing the mode of self-reflection revealed that Russian students were more apt than Americans to examine their feelings from a third-person or observer's perspective, reconstruing the experiential details rather than recounting them from a first-person point of view. Distancing oneself in such a fashion mediated the opposite influences of American versus Russian cultures on the relation between self-reflection and negative affect.

The Web and the end of forgetting

I need to pass on a 'must read' article by Jeffrey Rosen that has been on my list of potential mindblog posts. He describes the impossibility of ever removing the traces of ourselves that we have left on the Web, and the social consequences of this fact. Here are just a few clips from his very thorough article:

...The end of the Western frontier led to worries that Americans could no longer seek a fresh start and leave their past behind, a kind of reinvention associated with the phrase “G.T.T.,” or “Gone to Texas.” But the dawning of the Internet age promised to resurrect the ideal of … the “protean self.” If you couldn’t flee to Texas, you could always seek out a new chat room and create a new screen name… What seemed within our grasp was a power that only Proteus possessed: namely, perfect control over our shifting identities…But the hope that we could carefully control how others view us in different contexts has proved to be another myth. As social-networking sites expanded, it was no longer quite so easy to have segmented identities: now that so many people use a single platform to post constant status updates and photos about their private and public activities, the idea of a home self, a work self, a family self and a high-school-friends self has become increasingly untenable….far from giving us a new sense of control over the face we present to the world, the Internet is shackling us to everything that we have ever said, or that anyone has said about us, making the possibility of digital self-reinvention seem like an ideal from a distant era.

ReputationDefender, which has customers in more than 100 countries, is the most successful of the handful of reputation-related start-ups that have been growing rapidly after the privacy concerns raised by Facebook and Google... For a fee, the company will monitor your online reputation, contacting Web sites individually and asking them to take down offending items. In addition, with the help of the kind of search-optimization technology that businesses use to raise their Google profiles, ReputationDefender can bombard the Web with positive or neutral information about its customers, either creating new Web pages or by multiplying links to existing ones to ensure they show up at the top of any Google search. ..By automatically raising the Google ranks of the positive links, ReputationDefender pushes the negative links to the back pages of a Google search, where they’re harder to find.

In the nearer future, Internet searches for images are likely to be combined with social-network aggregator search engines, like today’s Spokeo and Pipl, which combine data from online sources — including political contributions, blog posts, YouTube videos, Web comments, real estate listings and photo albums. Increasingly these aggregator sites will rank people’s public and private reputations, like the new Web site Unvarnished, a reputation marketplace where people can write anonymous reviews about anyone. In the Web 3.0 world, Fertik predicts, people will be rated, assessed and scored based not on their creditworthiness but on their trustworthiness as good parents, good dates, good employees, good baby sitters or good insurance risks.

Anticipating these challenges, some legal scholars have begun imagining new laws that could allow people to correct, or escape from, the reputation scores that may govern our personal and professional interactions in the future. Jonathan Zittrain, who teaches cyberlaw at Harvard Law School, supports an idea he calls “reputation bankruptcy,” which would give people a chance to wipe their reputation slates clean and start over. To illustrate the problem, Zittrain showed me an iPhone app called Date Check, by Intelius, that offers a “sleaze detector” to let you investigate people you’re thinking about dating — it reports their criminal histories, address histories and summaries of their social-networking profiles. Services like Date Check, Zittrain said, could soon become even more sophisticated, rating a person’s social desirability based on minute social measurements — like how often he or she was approached or avoided by others at parties (a ranking that would be easy to calibrate under existing technology using cellphones and Bluetooth). Zittrain also speculated that, over time, more and more reputation queries will be processed by a handful of de facto reputation brokers — like the existing consumer-reporting agencies Experian and Equifax, for example — which will provide ratings for people based on their sociability, trustworthiness and employability.

Jorge Luis Borges, in his short story “Funes, the Memorious,” describes a young man who, as a result of a riding accident, has lost his ability to forget. Funes has a tremendous memory, but he is so lost in the details of everything he knows that he is unable to convert the information into knowledge and unable, as a result, to grow in wisdom. Viktor Mayer-Schönberger, in “Delete,” uses the Borges story as an emblem for the personal and social costs of being so shackled by our digital past that we are unable to evolve and learn from our mistakes. After reviewing the various possible legal solutions to this problem, Mayer-Schönberger says he is more convinced by a technological fix: namely, mimicking human forgetting with built-in expiration dates for data. He imagines a world in which digital-storage devices could be programmed to delete photos or blog posts or other data that have reached their expiration dates, and he suggests that users could be prompted to select an expiration date before saving any data.

Good and Bad in the Hands of Politicians

Casasanto1 and Jasmin do an interesting study that shows a link between action and emotion, positive messages are more strongly associated with dominant hand gestures and negative messages with non-dominant hand gestures.

We analyzed speech and gesture (3012 spoken clauses, 1747 gestures) from the final debates of the 2004 and 2008 US presidential elections, which involved two right-handers (Kerry, Bush) and two left-handers (Obama, McCain). Blind, independent coding of speech and gesture allowed objective hypothesis testing. Right- and left-handed candidates showed contrasting associations between gesture and speech. In both of the left-handed candidates, left-hand gestures were associated more strongly with positive-valence clauses and right-hand gestures with negative-valence clauses; the opposite pattern was found in both right-handed candidates...The results suggest that the hand speakers use to gesture may have unexpected (and probably unintended) communicative value, providing the listener with a subtle index of how the speaker feels about the content of the co-occurring speech.

Deconstructing science blogs

Wow, I guess I didn't realize what I was missing because of my habit of largely ignoring other science blogs (Jonah Leher's outstanding "Frontal Cortex" blog excepted), preferring to spend my time trolling for original source articles. Virginia Heffernan describes a massive defection of bloggers from Seed Media's ScienceBlogs group, and her subsequent perusing of the group's blogging products. She says that she:

...discovered that ScienceBlogs has become preoccupied with trivia, name-calling and saber rattling. Maybe that’s why the ScienceBlogs ship started to sink.

Recently a blogger called GrrlScientist, on Living the Scientific Life (Scientist, Interrupted), expressed her disgust at the “flock of hugely protruding bellies and jiggling posteriors everywhere I go.” Gratuitous contempt like this is typical. Mark Hoofnagle on Denialism Blog sideswiped those who question antibiotics, writing, “their particular ideology requires them to believe in the primacy of religion (Christian Science, New Age Nonsense) or in the magical properties of nature.” Over at Pharyngula — which often ranks in the Top 100 blogs on the Internet— PZ Myers revels in sub-“South Park” blasphemy, presenting (in one recent stunt) his sketch of the Prophet Muhammad as a cow-pig hybrid excited about “raping a 9-year-old girl.”

Clearly I’ve been out of some loop for too long, but does everyone take for granted now that science sites are where graduate students, researchers, doctors and the “skeptical community” go not to interpret data or review experiments but to chip off one-liners, promote their books and jeer at smokers, fat people and churchgoers? And can anyone who still enjoys this class-inflected bloodsport tell me why it has to happen under the banner of science?

Hammering away at an ideology, substituting stridency for contemplation, pummeling its enemies in absentia: ScienceBlogs has become Fox News for the religion-baiting, peak-oil crowd. Though Myers and other science bloggers boast that they can be jerky in the service of anti-charlatanism, that’s not what’s bothersome about them. What’s bothersome is that the site is misleading. It’s not science by scientists, not even remotely; it’s science blogging by science bloggers. And science blogging, apparently, is a form of redundant and effortfully incendiary rhetoric that draws bad-faith moral authority from the word “science” and from occasional invocations of “peer-reviewed” thises and thats.

I think she overstates her case a bit, but I did take the time to scan some of the mentioned blogs, and indeed there was more gratuitous nastiness than I thought appropriate.

Speakers and Listeners - fMRI shows coupled brains

As a followup to Monday's post on mirror neurons, this fascinating study by Stephens et al. shows that brain activities in a speaker-listener pair are tightly coupled, and that the magnitude of activity in areas exhibiting predictive anticipatory responses correlates with understanding. The graphic summaries of fMRI data in this open access article are quite nice, and you might want to check them out. The MindBlog reader who pointed out this early PNAS publication to me wonders "Could their findings open a new window of how to interpret the "function" of "conscious self", with the conscious self as the evaluating "outpost" of the coupled companion.?"

Verbal communication is a joint activity; however, speech production and comprehension have primarily been analyzed as independent processes within the boundaries of individual brains. Here, we applied fMRI to record brain activity from both speakers and listeners during natural verbal communication. We used the speaker's spatiotemporal brain activity to model listeners’ brain activity and found that the speaker's activity is spatially and temporally coupled with the listener's activity. This coupling vanishes when participants fail to communicate. Moreover, though on average the listener's brain activity mirrors the speaker's activity with a delay, we also find areas that exhibit predictive anticipatory responses. We connected the extent of neural coupling to a quantitative measure of story comprehension and find that the greater the anticipatory speaker–listener coupling, the greater the understanding. We argue that the observed alignment of production- and comprehension-based processes serves as a mechanism by which brains convey information.

Universities on the Web

Every time I delve into the MIT Open-CourseWare (OCW) site, I am blown away by the variety and quality of the offerings. d'Oliveira et al. describe the OpenCourseWare project in the July 30 issue of Science:

MIT Open-CourseWare (OCW), available at http://ocw.mit.edu, contains the core academic content used in 2000 classes, presenting substantially all the undergraduate and graduate curriculum from MIT's 33 academic departments. A selection of courses, including introductory physics, math, and engineering, contain full video lectures. Partner organizations have created more than 800 translations of OCW courses in five languages. The OCW team has distributed over 200 copies of the entire Web site on hard drives primarily to sub-Saharan Africa, where Internet access is limited. OCW has grown into a global educational resource.

More than 200 universities worldwide have joined MIT in sharing their own educational materials openly, creating a global body of knowledge that spans many cultures and academic levels. More than 13,000 courses from these schools are available through the OpenCourseWare Consortium portal (http://ocwconsortium.org)

In 2007, OCW introduced a companion site, Highlights for High School (http://ocw.mit.edu/highschool), which catalogs more than 2600 resources embedded in the main OCW site that correspond to U.S. Advanced Placement curricula for physics, calculus, and biology. The Highlights site has received more than 1 million visits since launch, and 70% of visitors report being mostly or completely successful at meeting their educational goals in accessing the site.

This fall, OCW will begin to introduce course materials designed specifically for use by independent learners, which will include complete sets of content, increased focus on problem-solving, and additional self-assessment opportunities. Through these and other pilot programs, the OCW team hopes to develop a better understanding of how to increase the benefits for this varied global audience.

Effect of irrelevant events on voters' evaluations

This study by Healy et al. is interesting. If your home team wins a big game, the incumbent in a subsequent election is favored. Also, surprising wins and losses affect approval of presidential performance:

Does information irrelevant to government performance affect voting behavior? If so, how does this help us understand the mechanisms underlying voters’ retrospective assessments of candidates’ performance in office? To precisely test for the effects of irrelevant information, we explore the electoral impact of local college football games just before an election, irrelevant events that government has nothing to do with and for which no government response would be expected. We find that a win in the 10 d before Election Day causes the incumbent to receive an additional 1.61 percentage points of the vote in Senate, gubernatorial, and presidential elections, with the effect being larger for teams with stronger fan support. In addition to conducting placebo tests based on postelection games, we demonstrate these effects by using the betting market's estimate of a team's probability of winning the game before it occurs to isolate the surprise component of game outcomes. We corroborate these aggregate-level results with a survey that we conducted during the 2009 NCAA men's college basketball tournament, where we find that surprising wins and losses affect presidential approval. An experiment embedded within the survey also indicates that personal well-being may influence voting decisions on a subconscious level. We find that making people more aware of the reasons for their current state of mind reduces the effect that irrelevant events have on their opinions. These findings underscore the subtle power of irrelevant events in shaping important real-world decisions and suggest ways in which decision making can be improved.

Being wrong...

I've been meaning to point out a Dwight Garner review on two books on humans making errors, “Being Wrong,” by Kathryn Schulz, and “Wrong,” by David H. Freedman. Daniel Gilbert offers a further review of the Schulz book, which appears to have won uniform praise from many reviewers:

...an insightful and delightful discussion of the errors of our ways — why we make mistakes, why we don’t know we are making them and what we do when recognition dawns. ...Ms. Schulz’s book is a funny and philosophical meditation on why error is mostly a humane, courageous and extremely desirable human trait. She flies high in the intellectual skies, leaving beautiful sunlit contrails. God isn’t her co-pilot; Iris Murdoch seems to be...Mr. Freedman’s book is a somewhat cruder vehicle. It’s a John Stossel-like exposé of the multiple ways that society’s so-called experts (scientists, economists, doctors) let us down, if not outright betray us. It’s a chunk of spicy populist outrage, and it can be a hoot to watch Mr. Freedman’s reading glasses steam up as he, like Big Daddy in “Cat on a Hot Tin Roof,” sniffs mendacity around the plantation.

I tweet, therefore I am...

This piece by Peggy Orenstein in yesterday's New York Times Sunday Magazine gave me an 'a ha' moment as one of its passages made clear to me why, after setting up and starting to do Twitter posts (tweets), I've felt a real inertia about generating tweets as I came across interesting and sometimes self-defining bits of material. In a sense it feels like like I am violating my own privacy, and Orenstein puts it nicely as she notes blurring "the lines not only between public and private but also between the authentic and contrived self. Some clips:

Each Twitter post seemed a tacit referendum on who I am, or at least who I believe myself to be...Each put a different spin on the occasion, of who I was within it...it was about how I imagined — and wanted — others to react to them... How much, I began to wonder, was I shaping my Twitter feed, and how much was Twitter shaping me?

Back in the 1950s, the sociologist Erving Goffman famously argued that all of life is performance: we act out a role in every interaction, adapting it based on the nature of the relationship or context at hand. Twitter has extended that metaphor to include aspects of our experience that used to be considered off-set: eating pizza in bed, reading a book in the tub, thinking a thought anywhere, flossing. Effectively, it makes the greasepaint permanent, blurring the lines not only between public and private but also between the authentic and contrived self. If all the world was once a stage, it has now become a reality TV show: we mere players are not just aware of the camera; we mug for it.

(Funny thing... after writing this post yesterday morning I found myself yesterday afternoon mysteriously starting to send out tweets on articles I was finding interesting.)

(Mis)understanding mirror neurons

This may be a bit technical for many MindBlog readers, but Hickok and Hauser offer a simple, succinct, and incisive critique of the current dogma about mirror neurons that is sufficiently important that I would like to pass it on.  They suggest, as an alternative to the common assumption that mirror neurons are involved in action understanding, that their activity instead might reflect sensory-motor learning. They illustrate this distinction with a simple graphic (in which ventral stream refers to pathways moving more through the temporal lobe of the brain - the 'what' pathway, with dorsal stream routing more through the parietal lobe - the 'where' pathway. Both pathways converge in pre-motor cortical areas such as F5):

Summary
It is hard to imagine a class of neurons that has generated more excitement than mirror neurons, cells discovered by Rizzolatti and colleagues [1] in macaque area F5 that fire both during action execution and action observation. We suggest, however, that the interpretation of mirror neurons as supporting action understanding was a wrong turn at the start, and that a more appropriate interpretation was lying in wait with respect to sensorimotor learning. We make a number of arguments, as follows. Given their previous work, it would have been natural for Rizzolatti's group to interpret mirror neurons as involved in action selection rather than action understanding. They did not make this assumption because, at the time, the data suggested that monkey behavior did not support such an interpretation. Recent evidence shows that monkeys do, in fact, exhibit behaviors that support this alternative interpretation. Thus, the original basis for claiming that mirror neurons mediate action understanding is no longer compelling. There are independent arguments against the action understanding claim and in support of a sensorimotor learning origin for mirror neurons. Therefore, the action understanding theory of mirror neuron function requires serious reconsideration, if not abandonment.
Main Text
Mirror neurons were discovered in the context of research aimed at understanding how the visual properties of objects are integrated with motor codes for action. Cells in area F5 were found to respond to visually presented objects as well as during grasping actions towards those objects. The interpretation of this circuit was that it coded a “vocabulary of motor acts and that this vocabulary can be accessed by … visual stimuli” (p. 491) [2] and that it was critical for “learning associations, including arbitrary associations between stimuli and [motor] schemas” (p. 317) [3]. This is a “‘pragmatic’ mode of processing, the function of which is to extract parameters that are relevant to action, and to generate the corresponding motor commands” (p. 320), as opposed to “‘semantic’ analysis [which is] performed in the temporal lobe” (p.314) [3]. Thus, the meaning of objects is not coded in F5, although clearly, “the semantic system can influence the pragmatic system” (p. 320) [3] (for example, we want to reach for food not snakes).

Mirror neurons were discovered within this same circuit and found to have similar sensorimotor properties [1,4]. It was even suggested that “the actions performed by other monkeys must be a very important factor in determining action selection” (p. 179) [4] and that “the [motor] vocabulary of F5 can be addressed in two ways: by objects and by events [actions]” (p. 317) [3]. Thus, the theoretical and empirical pieces were in place to interpret mirror neurons as sensorimotor association cells relevant to action selection, just like object-oriented cells (Figure 1). But this interpretation was not considered — why?

Figure 1 (click to enlarge)
Schematic models of dorsal and ventral stream function.
(A) The current dominant model [1], which holds that object- and action-oriented processes for sensorimotor integration and ‘understanding’ are organized differentially, with action understanding part of the dorsal sensorimotor stream and object ‘understanding’ part of the ventral stream. (B) A more conventional model in which object- and action-oriented processes for sensory-motor integration and understanding are organized similarly. Both models assume that semantic information from the ventral stream can modulate sensorimotor processes in the dorsal stream.

It was the mirroring property of mirror neurons that steered investigators away from a straightforward sensorimotor interpretation. The logic was, if mirror actions (for example, imitation) are not in the species' repertoire, then mirror neurons can have no motor selection function. Rizzolatti and Craighero used this argument, pitting “two main hypotheses” of mirror neuron function, imitation and action understanding; because macaques do not imitate, they argued, mirror neurons must support action understanding (p. 172) [1]. However, these authors, and the field generally, have failed to notice that other forms of mirror actions are in the macaque motor repertoire. For example, field studies show that rhesus monkeys perceive human gestures as goal-directed, including those that mimic the rhesus monkeys' species-specific signal for coalition recruitment [5]. Macaques also engage in contagious yawning, where perception of another's yawn triggers a yawn in the observer [6]. Further, experimental work has found that another's grasping actions toward one of two food receptacles serves as a cue to goal-directed grasping toward that same receptacle [7] — an experimental situation reminiscent of the mirror neuron studies. Even domesticated dogs mirror goal-directed actions of a model dog [8]; one would expect to find mirror neurons in dogs given this behavioral evidence. And lastly, rhesus monkeys comprehend actions that they are physically incapable of producing. In particular, though rhesus monkeys do not throw, they can recognize a throwing action in humans, realizing that throwing a rock is dangerous whereas throwing food is not [5].

Observed actions can serve as important inputs to action selection, including, but not necessarily limited to, mirror actions. Therefore, the motivating argument for the action understanding theory over a sensorimotor theory (for example [9]) does not hold.

Can we distinguish the sensorimotor and action understanding theories of mirror neurons? Yes: empirical findings favor the sensorimotor account by showing that action understanding and motor system function dissociate [10], that motor actions alone are insufficient to explain action understanding [5], that animals comprehend many actions that they cannot execute [10], and that sensorimotor learning can transform the mirror system [9].

In summary, a sensorimotor theory can explain the response properties of mirror neurons, does so more straightforwardly, and does not suffer the empirical roadblocks of the action understanding theory [5,10]. It is time to reconsider mirror neuron function and the neural basis of action understanding.

References
1 Rizzolatti, G., and Craighero, L. (2004). The mirror-neuron system. Annu. Rev. Neurosci. 27, 169–192.
2 Rizzolatti, G., Camarda, R., Fogassi, L., Gentilucci, M., Luppino, G., and Matelli, M. (1988). Functional organization of inferior area 6 in the macaque monkey. II. Area F5 and the control of distal movements. Exp. Brain Res. 71, 491–507.
3 Jeannerod, M., Arbib, M.A., Rizzolatti, G., and Sakata, H. (1995). Grasping objects: the cortical mechanisms of visuomotor transformation. Trends Neurosci. 18, 314–320.
4 di Pellegrino, G., Fadiga, L., Fogassi, L., Gallese, V., and Rizzolatti, G. (1992). Understanding motor events: a neurophysiological study. Exp. Brain Res. 91, 176–180.
5 Hauser, M., and Wood, J. (2010). Evolving the capacity to understand actions, intentions, and goals. Annu. Rev. Psychol 61, 303–324, C301.
6 Paukner, A., and Anderson, J.R. (2006). Video-induced yawning in stumptail macaques (Macaca arctoides). Biol. Lett. 2, 36–38.
7 Wood, J.N., Glynn, D.D., Phillips, B.C., and Hauser, M.D. (2007). The perception of rational, goal-directed action in nonhuman primates. Science 317, 1402–1405.
8 Range, F., Viranyi, Z., and Huber, L. (2007). Selective imitation in domestic dogs. Curr. Biol. 17, 868–872.
9 Heyes, C. (2010). Where do mirror neurons come from?. Neurosci. Biobehav. Rev. 34, 575–583.
10 Hickok, G. (2009). Eight problems for the mirror neuron theory of action understanding in monkeys and humans. J. Cogn. Neurosci. 21, 1229–1243.

Resilience in the face of adversity - brain correlates

Interesting work from Dolan's group on how we modulate expected aversive outcomes:

The value assigned to aversive events is susceptible to contextual influences. Here, we asked whether a change in the valuation of negative events is reflected in an altered neuronal representation of their expected aversive outcome. We show that experiencing an aversive event in the past, and choosing to experience it in the future, reduces its aversive value. This psychological change is mirrored in an altered neural representation of aversive value in the caudate nucleus and anterior cingulate cortex. Our findings indicate that subcortical regions known to track expected value such as the caudate nucleus, together with anterior cingulate cortical regions implicated in emotional modulation, mediate a revaluation in expectancies of aversive states. The results provide a striking example of a contextual sensitivity in how the brain ascribes value to events, in a manner that may foster resilience in the face of adversity.

Reciprocity engages our brain's reward system.

Interesting stuff from Phan et al:

Brain reward circuitry, including ventral striatum and orbitofrontal cortex, has been independently implicated in preferences for fair and cooperative outcomes as well as learning of reputations. Using functional MRI (fMRI) and a “trust game” task involving iterative exchanges with fictive partners who acquire different reputations for reciprocity, we measured brain responses in 36 healthy adults when positive actions (entrust investment to partners) yield positive returns (reciprocity) and how these brain responses are modulated by partner reputation for repayment. Here we show that positive reciprocity robustly engages the ventral striatum and orbitofrontal cortex. Moreover, this signal of reciprocity in the ventral striatum appears selectively in response to partners who have consistently returned the investment (e.g., a reputation for reciprocity) and is absent for partners who lack a reputation for reciprocity. These findings elucidate a fundamental brain mechanism, via reward-related neural substrates, by which human cooperative relationships are initiated and sustained.

Twitter-mood

Here is a cute study that attempts to gauge  our mood (more accurately, the 7% of American who use Twitter) throughout the day.  Play through the video that shows regional and time of day differences.  From the quickie NYTimes mention of the work: "you’re probably happiest in the morning and least satisfied about noon. Analyzing words in those posts, researchers found that Thursday is the saddest day; Sunday, the happiest. People on the West Coast who post are happier than their counterparts on the East Coast. The moods were mapped, showing happy times (greener areas) and unhappy (red areas)."

Altruism as good business - shoppers who care

Gneezy et al. add an interesting twist to studies of how we buy things. Companies loose money in attempts to enhance sales with pay-what-you-want pricing, and adding a charitable contribution to standard pricing has little effect. However, in a variation of pay-what-you-want with half going to charity, a more reasonable profit was returned. (It is not clear whether the charitable giving by the company generated additional generosity by the consumer or created additional social pressure.)

A field experiment (N = 113,047 participants) manipulated two factors in the sale of souvenir photos. First, some customers saw a traditional fixed price, whereas others could pay what they wanted (including $0). Second, approximately half of the customers saw a variation in which half of the revenue went to charity. At a standard fixed price, the charitable component only slightly increased demand, as similar studies have also found. However, when participants could pay what they wanted, the same charitable component created a treatment that was substantially more profitable. Switching from corporate social responsibility to what we term shared social responsibility works in part because customized contributions allow customers to directly express social welfare concerns through the purchasing of material goods.

Monetary favors bias judgement in unrelated domains

Work from Read Montague's group at Baylor College of Medicine in Houston, Texas, that explains how corporate sponsorship (of athletic or artistic events) can bias our judgements in a very general way:

Favors from a sender to a receiver are known to bias decisions made by the recipient, especially when the decision relates to the sender, a feature of social exchange known as reciprocity. Using an art-viewing paradigm possessing no objectively correct answer for preferring one piece of art over another, we show that sponsorship of the experiment by a company endows the logo of the company with the capacity to bias revealed preference for art displayed next to the logo. Merely offering to sponsor the experiment similarly endowed the gesturing logo of the company with the capacity to bias revealed preferences. These effects do not depend upon the size of the displayed art or the proximity of the sponsoring logo to the piece of art. We used functional magnetic resonance imaging to show that such monetary favors do not modulate a special collection of brain responses but instead modulate responses in neural networks normally activated by a wide range of preference judgments. The results raise the important possibility that monetary favors bias judgments in domains seemingly unrelated to the favor but nevertheless act in an implicit way through neural networks that underlie normal, ongoing preference judgments.

Our bias towards negative interpretation of ambiguous faces

Neta and Whalen make some interesting observations (on the usual cadre of undergraduate psychology students usually involved in such studies), showing that we have a 'better be safe than sorry' strategy in responding to ambiguous expressions of surprise that could signal either a negative or positive situation.  We pick the negative interpretation, and our background bias towards being positive or negative biases this effect.:

Low-spatial-frequency (LSF) visual information is processed in an elemental fashion before a finer analysis of high-spatial-frequency information. Further, the amygdala is particularly responsive to LSF information contained within negative (e.g., fearful) facial expressions. In a separate line of research, it has been shown that surprised facial expressions are ambiguous in that they can be interpreted as either negatively or positively valenced. More negative interpretations of surprise are associated with increased ventral amygdala activity. In this report, we show that LSF presentations of surprised expressions bias the interpretation of surprised expressions in a negative direction, a finding suggesting that negative interpretations are first and fast during the resolution of ambiguous valence.

Nuturing robots

A recent article by Benedict Carey suggests we may be heading towards a future in which instructional and emotional needs of those not able to obtain appropriate human contact are met through presentation of changing robotic emotional expressions that activate the same brain areas as normal human gestures. A report by Chaminade et al., however, on a multi-national collaboration involving the humanoid robot WE4-RII - which expresses emotions by using facial expressions and the movement of the upper-half of the body including neck, shoulders, trunk, waist, as well as arms and hands - suggests that we have some way to go:

...activity in cortical areas endowed with mirror properties, like left Broca's area for the perception of speech, and in the processing of emotions like the left anterior insula for the perception of disgust and the orbitofrontal cortex for the perception of anger, is reduced for robot stimuli, suggesting lesser resonance with the mechanical agent. Finally, instructions to explicitly attend to the emotion significantly increased response to robot, but not human facial expressions in the anterior part of the left inferior frontal gyrus, a neural marker of motor resonance.

The Carey article reviews a number of different robotic instructional studies that show, in spite of the attenuated effectiveness of robotic versus human emotions, that robots can engage people and teach them simple skills, including household tasks, vocabulary or, in the case of autistic children, playing, elementary imitation and taking turns.

Perceptual training enhances working memory in older adults.

Berry et al. demonstrate that training the visual discrimination of older adults enhances working memory, a cross-domain brain enhancement. (The visual discrimination task involved detecting whether a sine pattern grating was expanding or contracting. Training was adaptive such that the speed of expansion/contraction and the duration of the inter-stimulus interval scaled with improvements in response accuracy, so as to continuously challenge the trainees. The working memory test used a delayed recognition paradigm.):

Normal aging is associated with a degradation of perceptual abilities and a decline in higher-level cognitive functions, notably working memory. To remediate age-related deficits, cognitive training programs are increasingly being developed. However, it is not yet definitively established if, and by what mechanisms, training ameliorates effects of cognitive aging. Furthermore, a major factor impeding the success of training programs is a frequent failure of training to transfer benefits to untrained abilities. Here, we offer the first evidence of direct transfer-of-benefits from perceptual discrimination training to working memory performance in older adults. Moreover, using electroencephalography to evaluate participants before and after training, we reveal neural evidence of functional plasticity in older adult brains, such that training-induced modifications in early visual processing during stimulus encoding predict working memory accuracy improvements. These findings demonstrate the strength of the perceptual discrimination training approach by offering clear psychophysical evidence of transfer-of-benefit and a neural mechanism underlying cognitive improvement.

Sex promotes generation of new brain cells.

Stress usually adversely affects hippocampal structure and function in adult rats, inhibits cell division, and produces anxiety-like behavior. Leuner et al. show, however, that the stress associated with repeated (chronic) copulation has the opposite effect. The generation of new cells by cell division is stimulated and anxiety-like behaviors diminish. (Is this why I feel so mellow after...?) Here is the abstract:

Aversive stressful experiences are typically associated with increased anxiety and a predisposition to develop mood disorders. Negative stress also suppresses adult neurogenesis and restricts dendritic architecture in the hippocampus, a brain region associated with anxiety regulation. The effects of aversive stress on hippocampal structure and function have been linked to stress-induced elevations in glucocorticoids. Normalizing corticosterone levels prevents some of the deleterious consequences of stress, including increased anxiety and suppressed structural plasticity in the hippocampus. Here we examined whether a rewarding stressor, namely sexual experience, also adversely affects hippocampal structure and function in adult rats. Adult male rats were exposed to a sexually-receptive female once (acute) or once daily for 14 consecutive days (chronic) and levels of circulating glucocorticoids were measured. Separate cohorts of sexually experienced rats were injected with the thymidine analog bromodeoxyuridine in order to measure cell proliferation and neurogenesis in the hippocampus. In addition, brains were processed using Golgi impregnation to assess the effects of sexual experience on dendritic spines and dendritic complexity in the hippocampus. Finally, to evaluate whether sexual experience alters hippocampal function, rats were tested on two tests of anxiety-like behavior: novelty suppressed feeding and the elevated plus maze. We found that acute sexual experience increased circulating corticosterone levels and the number of new neurons in the hippocampus. Chronic sexual experience no longer produced an increase in corticosterone levels but continued to promote adult neurogenesis and stimulate the growth of dendritic spines and dendritic architecture. Chronic sexual experience also reduced anxiety-like behavior. These findings suggest that a rewarding experience not only buffers against the deleterious actions of early elevated glucocorticoids but actually promotes neuronal growth and reduces anxiety.

MRI evidence on how hypnosis works.

I just came across a paper by Cojan et al. on brain activity under hypnosis. While undergoing functional MRI, participants were instructed to prepare to move their hand. After a few seconds they were told whether or not to actually perform the movement. Some of the time, they were hypnotized and believed that their hand was paralyzed. Interestingly, when the volunteers were under hypnosis, the preparatory activity in motor cortex was normal; but there was increased activity in other regions related to attention, mental imagery and self-awareness. Moreover, the connectivity between these regions and motor cortex was enhanced, indicating that hypnosis doesn’t work by directly controlling motor activity, but rather through the effects of internal representations and self-monitoring processes on such activity. Here is the authors' summary of the work:

Brain mechanisms of hypnosis are poorly known. Cognitive accounts proposed that executive attentional systems may cause selective inhibition or disconnection of some mental operations. To assess motor and inhibitory brain circuits during hypnotic paralysis, we designed a go-nogo task while volunteers underwent functional magnetic resonance imaging (fMRI) in three conditions: normal state, hypnotic left-hand paralysis, and feigned paralysis. Preparatory activation arose in right motor cortex despite left hypnotic paralysis, indicating preserved motor intentions, but with concomitant increases in precuneus regions that normally mediate imagery and self-awareness. Precuneus also showed enhanced functional connectivity with right motor cortex. Right frontal areas subserving inhibition were activated by nogo trials in normal state and by feigned paralysis, but irrespective of motor blockade or execution during hypnosis. These results suggest that hypnosis may enhance self-monitoring processes to allow internal representations generated by the suggestion to guide behavior but does not act through direct motor inhibition.

Directly controlling 'fear' cells in the brain.

LeDoux and collaborators have done the clever experiment (in rats) of introducing an optically activated molecular label into cells in the amygdala thought to be causal in fear conditioning. Activation of these cells by light just after presentation of a auditory sensory cue (but with no aversive stimulus) caused the rats to exhibit behavioral fear responses when the cue was subsequently presented.

Humans and animals can learn that specific sensory cues in the environment predict aversive events through a form of associative learning termed fear conditioning. This learning occurs when the sensory cues are paired with an aversive event occuring in close temporal proximity. Activation of lateral amygdala (LA) pyramidal neurons by aversive stimuli is thought to drive the formation of these associative fear memories; yet, there have been no direct tests of this hypothesis. Here we demonstrate that viral-targeted, tissue-specific expression of the light-activated channelrhodopsin (ChR2) in LA pyramidal cells permitted optical control of LA neuronal activity. Using this approach we then paired an auditory sensory cue with optical stimulation of LA pyramidal neurons instead of an aversive stimulus. Subsequently presentation of the tone alone produced behavioral fear responses. These results demonstrate in vivo optogenetic control of LA neurons and provide compelling support for the idea that fear learning is instructed by aversive stimulus-induced activation of LA pyramidal cells.

Fool the brain to enhance performance with a carbohydrate rinse

Kolata reports on exercise physiologists stumbling on an unexpected feature: simply rinsing the mouth with a carbohydrate solution stimulates receptors that report to the brain, causing it to instruct increased intensity and duration of effort in anticipation of an imminent food reward.