Wednesday, September 17, 2008

Stress during pregnancy hard on males

Mueller and Bale offer more information on what stress in female mice during pregnancy can do, particularly to male offspring:
Prenatal stress is associated with an increased vulnerability to neurodevelopmental disorders, including autism and schizophrenia. To determine the critical time window when fetal antecedents may induce a disease predisposition, we examined behavioral responses in offspring exposed to stress during early, mid, and late gestation. We found that male offspring exposed to stress early in gestation displayed maladaptive behavioral stress responsivity, anhedonia, and an increased sensitivity to selective serotonin reuptake inhibitor treatment. Long-term alterations in central corticotropin-releasing factor (CRF) and glucocorticoid receptor (GR) expression, as well as increased hypothalamic–pituitary–adrenal (HPA) axis responsivity, were present in these mice and likely contributed to an elevated stress sensitivity. Changes in CRF and GR gene methylation correlated with altered gene expression, providing important evidence of epigenetic programming during early prenatal stress. In addition, we found the core mechanism underlying male vulnerability may involve sex-specific placenta responsivity... in male placentas but not females. Examination of placental epigenetic machinery revealed basal sex differences, providing further evidence that sex-specific programming begins very early in pregnancy, and may contribute to the timing and vulnerability of the developing fetus to maternal perturbations. Overall, these results indicate that stress experience early in pregnancy may contribute to male neurodevelopmental disorders through impacts on placental function and fetal development.

Tuesday, September 16, 2008

More on digitial intimacy - MindBlog followers and demographics

No sooner have I done yesterday's posting on the 'ambient intimacy' generated by services like Facebook and Twitter than I find on logging in to my Blogger.com dashboard (menu) page a new icon indicating a feature I have been unaware of, 'followers' of the blog. I added the 'gadget' to the left column of this blog (I'll try anything once), and on reading a bit further discover that it appears to deal only with followers who have blogger accounts. They can choose to have the fact that they are following the blog be either private or have their name listed in the box.

I try not to pay attention to the myriad ways one can monitor a blog's traffic, but when the Scientific American people asked me to join their 'Partner's Network' (see the icon in the left column) they asked me to sign on to the quantcast.com analysis site. If you go to quantcast.com and simply enter mindblog.dericbownds.net in the box, you immediately get a detailed demongraphic analysis of this blog's readers: sex, age, income, and how many addicts, regulars, and passers-by there are.

Our aging brains - impaired suppression of distracting information

This work from Gazzaley et al. strikes WAY to close to home for me, as a description of my own aging (66 year old) brain, and why I get frustrated with the n-back memory exercise. Their abstract:
In this study, electroencephalography (EEG) was used to examine the relationship between two leading hypotheses of cognitive aging, the inhibitory deficit and the processing speed hypothesis. We show that older adults exhibit a selective deficit in suppressing task-irrelevant information during visual working memory encoding, but only in the early stages of visual processing. Thus, the employment of suppressive mechanisms are not abolished with aging but rather delayed in time, revealing a decline in processing speed that is selective for the inhibition of irrelevant information. EEG spectral analysis of signals from frontal regions suggests that this results from excessive attention to distracting information early in the time course of viewing irrelevant stimuli. Subdividing the older population based on working memory performance revealed that impaired suppression of distracting information early in the visual processing stream is associated with poorer memory of task-relevant information. Thus, these data reconcile two cognitive aging hypotheses by revealing that an interaction of deficits in inhibition and processing speed contributes to age-related cognitive impairment.

Monday, September 15, 2008

Digital Intimacy

Several years ago I set up a facebook account, looked up the pages of the students who were taking my seminar course, and at the end of the term told them about my experiment. They were mortified to find the professor had seen their self revelations about their sexual and boozing habits - as anyone on the web could have done. Now my daughter and her friends are broadcasting their latest moods and movements via the FaceBook feed, twitter, etc. This sort of freaks me out, the last thing I want is to surrender the last vestiges of my privacy to the greater web community. But, as Clive Thompson points out in his New York Times Magazine article, this new kind of ambient intimacy makes possible a kind of awareness of others not possible before .
Social scientists have a name for this sort of incessant online contact. They call it “ambient awareness.” It is, they say, very much like being physically near someone and picking up on his mood through the little things he does — body language, sighs, stray comments — out of the corner of your eye. Facebook is no longer alone in offering this sort of interaction online. In the last year, there has been a boom in tools for “microblogging”: posting frequent tiny updates on what you’re doing. ... One of the most popular new tools is Twitter, a Web site and messaging service that allows its two-million-plus users to broadcast to their friends haiku-length updates — limited to 140 characters, as brief as a mobile-phone text message — on what they’re doing. There are other services for reporting where you’re traveling (Dopplr) or for quickly tossing online a stream of the pictures, videos or Web sites you’re looking at (Tumblr). And there are even tools that give your location. When the new iPhone, with built-in tracking, was introduced in July, one million people began using Loopt, a piece of software that automatically tells all your friends exactly where you are.

This is the paradox of ambient awareness. Each little update — each individual bit of social information — is insignificant on its own, even supremely mundane. But taken together, over time, the little snippets coalesce into a surprisingly sophisticated portrait of your friends’ and family members’ lives, like thousands of dots making a pointillist painting. This was never before possible, because in the real world, no friend would bother to call you up and detail the sandwiches she was eating. The ambient information becomes like “a type of E.S.P.,” as Haley described it to me, an invisible dimension floating over everyday life.

You could also regard the growing popularity of online awareness as a reaction to social isolation, the modern American disconnectedness that Robert Putnam explored in his book “Bowling Alone.” The mobile workforce requires people to travel more frequently for work, leaving friends and family behind, and members of the growing army of the self-employed often spend their days in solitude. Ambient intimacy becomes a way to “feel less alone,” as more than one Facebook and Twitter user told me.

What will happen in the next ten years?

Nature magazine asked this question of ten prominent researchers and business people. A common theme emerges: the integration of the worlds of matter and information, whether it be by the blurring of boundaries between online and real environments, touchy-feely feedback from a phone or chromosomes tucked away on databases.

Friday, September 12, 2008

Brooks on how the Republicans just don't get it....

I thought I would pass on this link to David Brook's op-ed piece in today's New York Times, on how Republican party dogma is completely clueless on basic facts about our social brains that have been clearly proven by psychologists, social scientists, cognitive neuroscientists, etc.

Watching practice change the brain cortex.

Our brain cortex is changed by different kinds of learning. These include factual knowledge that is recalled by a purposeful effort and requires the involvement of the explicit memory system (This system is involved in tasks such as spatial navigation and intensive studying). Changes also result from training implicit memory, which refers to intrinsic knowledge about how to perform an action and includes language learning, juggling, mirror reading, and musical training. Duerden and Laverdure-Dupont do a meta-analysis of six morphometric studies that have demonstrated both short- and long-term use-dependent changes caused by these different types of learning. Although structural changes are commonly found in brain regions known to be functionally involved in the particular skill under study, a meta-analytic review of these studies revealed that additional changes often occurred in associative regions including parietal and temporal cortices. studies examining explicit learning showed an overlap of increased gray matter density in the hippocampal gyrus.


Figure - Meta-analysis of voxel-based morphometric studies reporting increased gray matter density after learning in the cortex and cerebellum.

Inducing persistent false beliefs is easy.

Just look at the political scene... But, seriously, the work in question is this interest tidbit from Geraerts et al in Psychological Sciences (the latest issue of this journal is a gold mine of interesting articles. I am porting a few of those abstract to this blog...)
False beliefs and memories can affect people's attitudes, at least in the short term. But can they produce real changes in behavior? This study explored whether falsely suggesting to subjects that they had experienced a food-related event in their childhood would lead to a change in their behavior shortly after the suggestion and up to 4 months later. We falsely suggested to 180 subjects that, as children, they had gotten ill after eating egg salad. Results showed that, after this manipulation, a significant minority of subjects came to believe they had experienced this childhood event even though they had initially denied having experienced it. This newfound autobiographical belief was accompanied by the intent to avoid egg salad, and also by significantly reduced consumption of egg-salad sandwiches, both immediately and 4 months after the false suggestion. The false suggestion of a childhood event can lead to persistent false beliefs that have lasting behavioral consequences.

Thursday, September 11, 2008

Listening to Resveratrol

David Kent writes a well balanced article in American Scientist on issues of human longevity. A graphic and some text on the consequences of lifespan-prolonging therapies on population growth and demographic structure:
In the past century, disease-specific medicine reduced mortality at all ages, including the economically productive years between one's 20s and 60s. Historical trends show an increasing "rectangularization" of mortality rates over the past century, meaning that most people survive to an advanced age, at which point there is a precipitous increase in the number of deaths (green curves). Such data have led some researchers to theorize that the human lifespan is reaching an "ideal" length, beyond which substantial extension is not possible. However, discoveries about the basic mechanisms of aging may permit life expectancy to extend beyond this theoretical limit (red curves).


The rectangularization of the mortality curve implies that life-prolonging therapies will add years only at the end of life. Unless there is a shift in the retirement age, 21st-century medical innovation will have an even more dramatic effect on the dependency ratio (a measure of the portion of a population composed of those either too old or too young to work). Maintaining retirement as a widespread option at around 65, already an economic stretch, undoubtedly will become untenable. The price of longer life will almost certainly be a longer work life.

Chinese kids are ahead even before elementary school...

More sobering data from Siegler and Mu on occidental versus oriental child development. The superior mathematical knowledge of East Asian preschoolers is not limited to skills that are taught directly by parents or in school but is more general.
Kindergartners in China showed greater numerical knowledge than their age peers in the United States, not only when tested with arithmetic problems, which Chinese parents present to their children more often than U.S. parents do, but also when tested with number-line estimation problems, which were novel to the children in both countries. The Chinese kindergartners' number-line estimates were comparable to those of U.S. children 1 to 2 years more advanced in school. Individual differences in arithmetic and number-line-estimation performance were positively correlated within each country. These results indicate that performance differences between Chinese and U.S. children on both practiced and unpracticed mathematical tasks are substantial even before the children begin elementary school.

Wednesday, September 10, 2008

Watching the testosterone crash in anxious men who lose a contest.

This work from Maner et al. makes a rather blunt point:
Although theory suggests a link between social anxiety and social dominance, direct empirical evidence for this link is limited. The present experiment tested the hypothesis that socially anxious individuals, particularly men, would respond to a social-dominance threat by exhibiting decrements in their testosterone levels, an endocrinological change that typically reflects pronounced social submission in humans and other animals. Participants were randomly assigned to either win or lose a rigged face-to-face competition with a confederate. Although no zero-order relationship between social anxiety and level of testosterone was observed, testosterone levels showed a pronounced drop among socially anxious men who lost the competition. No significant changes were observed in nonanxious men or in women. This research provides novel insight into the nature and consequences of social anxiety, and also illustrates the utility of integrating social psychological theory with endocrinological approaches to psychological science.


Figure: Change in testosterone level as a function of experimental condition (losers vs. winners) and social anxiety (1 SD above the mean vs. 1 SD below the mean). Results are presented separately for men and women. Change scores were standardized within each gender.

La gazza ladra passes the mirror test - a crow with a self!

The Eurasian magpie belongs to the same bird family that includes the crows, ravens, and jays. de Waal writes a fascinating review of recent work by Prior et al. that demonstrates that magpies recognize themselves in a mirror - a test that persists as the gold standard of self-identity or 'personhood.' The experiments actually had better controls than many of those done with apes and human children...
...which generally fail to include “sham” marks. A sham mark is applied in the same way as a visible mark, and supposed to feel and smell the same, but cannot be visibly detected. In the magpie study, this was done by placing a black mark onto the magpies' black throat feathers.

Placed on the same black throat feathers, the visible mark—a tiny colored sticker—stood out, but only in a mirror. Put in front of a mirror, the magpies kept scratching with their foot until the mark was gone, whereas they left the sham mark alone. They also didn't do the same amount of frantic scratching if there was no mirror to see themselves in. Evidently, their self-preening was guided by visual feedback from the mirror.

de Waal also discusses work with other species and the “co-emergence hypothesis,” according to which the capacities for mirror self recognition and perspective-taking appear in tandem during both evolution and development.

Speaking of crows, Nijhuis writes a brief piece on work showing that crows recognize individual human faces.

Tuesday, September 09, 2008

Neural correlates of consciousness

I just came across this succinct and informative site in Scholarpedia curated by Christof Koch and Florian Mormann at Cal. Tech. It has some useful instructional graphics.


Midline structures in the brainstem and thalamus necessary to regulate the level of brain arousal. Small, bilateral lesions in many of these nuclei cause a global loss of consciousness. (From Koch, 2004, The Quest for Consciousness: A Neurobiological Approach. Roberts, Denver, CO.)

When a referee sees red...

It has been shown that wearing red sports attire has a positive impact on one's outcome in combat sports such as tae kwon do or wrestling. One speculation has been that this is due to an evolutionary or cultural association of the color red with dominance and aggression, with this association triggering a psychological effects (dominance/submission) in the competitors. Hagemann et al. offer evidence that perceptual bias in the referee is the more likely explanation, by showing that when tae kwon do referees watch videos of matches in which the competitors wear either read or blue protective gear:
The competitor wearing red protective gear was awarded an average of 13% (0.94 points) more points than the competitor wearing blue protective gear. The number of points awarded increased for a blue competitor who was digitally transformed into a red competitor, and decreased for a red competitor who was digitally transformed into a blue competitor.

Monday, September 08, 2008

Culture shapes how we look at faces.

Studies of eye movements have persistently revealed a systematic triangular sequence of fixations over the eye and the mouth, with dominance to the eyes, suggesting that the presence of a face triggers a universal, biologically-determined information extraction pattern. However, the literature is based on observations with adults from Western cultures only. Blais et al. have monitored the eye movements of Western Caucasian and East Asian observers while they learned, recognized, and categorized by race Western Caucasian and East Asian faces. Western Caucasian observers reproduced a scattered triangular pattern of fixations for faces of both races and across tasks. Contrary to intuition, East Asian observers focused more on the central region of the face. The work suggests that face processing does not rise from a universal sequence of perceptual events, but rather that the strategy employed to extract visual information from faces differs across cultures.

Sleep preferentially enhances our emotional memories

Interesting observations from Payne et al. Sleep can preserve our memory of negative objects seen and then forgotten during the day, but not the background in which they originally appeared :
Central aspects of emotional experiences are often well remembered at the expense of background details. Previous studies of such memory trade-offs have focused on memory after brief delays, but little is known about how these components of emotional memories change over time. We investigated the evolution of memory for negative scenes across 30 min, 12 daytime hours spent awake, and 12 nighttime hours including sleep. After 30 min, negative objects were well remembered at the expense of information about their backgrounds. Time spent awake led to forgetting of the entire negative scene, with memories of objects and their backgrounds decaying at similar rates. Sleep, in contrast, led to a preservation of memories of negative objects, but not their backgrounds, a result suggesting that the two components undergo differential processing during sleep. Memory for a negative scene develops differentially across time delays containing sleep and wake, with sleep selectively consolidating those aspects of memory that are of greatest value to the organism.

Friday, September 05, 2008

Our body language of pride and shame is innate

Tracy and Matsumoto have performed an interesting cross cultural study of nonverbal displays of pride and shame in sighted, blind, and congenitally blind individuals:
The research examined whether the recognizable nonverbal expressions associated with pride and shame may be biologically innate behavioral responses to success and failure. Specifically, we tested whether sighted, blind, and congenitally blind individuals across cultures spontaneously display pride and shame behaviors in response to the same success and failure situations—victory and defeat at the Olympic or Paralympic Games. Results showed that sighted, blind, and congenitally blind individuals from >30 nations displayed the behaviors associated with the prototypical pride expression in response to success. Sighted, blind, and congenitally blind individuals from most cultures also displayed behaviors associated with shame in response to failure. However, culture moderated the shame response among sighted athletes: it was less pronounced among individuals from highly individualistic, self-expression-valuing cultures, primarily in North America and West Eurasia. Given that congenitally blind individuals across cultures showed the shame response to failure, findings overall are consistent with the suggestion that the behavioral expressions associated with both shame and pride are likely to be innate, but the shame display may be intentionally inhibited by some sighted individuals in accordance with cultural norms.


Mean levels of pride and shame nonverbal behaviors spontaneously displayed in response to match wins and losses by congenitally blind athletes.

MindBlog strikes it rich...

Here is the result of the little box of Google adds that I let run in the left column of this blog starting a little over a year ago. They send you a check after your cut of the revenue from clicks on the advertisements reaches $100. I guess I had better not quit my day job (being a retired professor).

Thursday, September 04, 2008

Subjective/Objective - applying real-time fMRI

R. Christopher deCharms offers an interesting review article on exploring the mind-body interface with neuroimaging. Here is the abstract, followed by one figure. The PDF is here.
For centuries people have aspired to understand and control the functions of the mind and brain. It has now become possible to image the functioning of the human brain in real time using functional MRI (fMRI), and thereby to access both sides of the mind–brain interface — subjective experience (that is, one's mind) and objective observations (that is, external, quantitative measurements of one's brain activity) — simultaneously. Developments in neuroimaging are now being translated into many new potential practical applications, including the reading of brain states, brain–computer interfaces, communicating with locked-in patients, lie detection, and learning control over brain activation to modulate cognition or even treat disease.


a) Descartes used introspection as a way to perceive the mechanisms of the mind. This approach to observing the mind–brain interface is what people were limited to in the absence of technology. b) Today, using real-time functional MRI, it is possible to measure the level of activation from approx216 brain locations per second. Here, measured activation levels are represented as colours that have been overlaid onto a three-dimensional rendered set of anatomical brain images. c) Information from individual spatial points can be segregated into multiple anatomically defined three-dimensional regions of interest. Here the activation levels (represented as colours) of three brain regions are rendered on a translucent 'glass brain' view. d) Activation in these regions can either be plotted second-by-second in real time or can be presented to subjects in more abstract forms, such as this virtual-reality video display of a beach bonfire, in which each of the three elements of the flickering fire corresponds to activation in a particular brain region. Brain activation can control arbitrarily complex elements of computer-generated scenarios.