Brain Buzz, a 9 volt battery and some wires...

Here in an engaging review by Douglas Fox, of efforts to enhance learning and intelligence by transcranial direct-current stimulation (tDCS), which is as simple as hooking up a 9 volt battery and an appropriate resistor (remember ohm's law? I= E/R) to deliver about a 2 milliamp current to the scalp. The US Defense Advanced Research Projects Agency has funded research showing that a video game designed to train US soldiers bound for Iraq is learned twice as quickly during the electrical stimulation. Fox discusses a number of other studies, as well as debate surrounding the technique.

Language evolution inferred from phonemic diversity

Atkinson has done an analysis that strongly points to a single African origin of modern human languages. The greatest diversity in phonemes (perceptually distinct units of sound that differentiate words) in languages spoken today is found in Africa. These include strange sounding (to westerners) clicks and staccato noises. His abstract, and a figure from the paper:

Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. Here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder–effect model of expansion from an inferred origin in Africa. This result, which is not explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.

Language locations and regional variation in phonemic diversity. (A) Map showing the location of the 504 sampled languages for which phoneme data was compiled from the WALS database. (B) Box plots of overall phonemic diversity by region reveal substantial regional variation, with the highest diversity in Africa and the lowest diversity in Oceania and South America. The same regional pattern also applies at the language family level.

Slow spring at Twin Valley

I returned to the 1860 stone schoolhouse that is my home in Middleton Wisconsin April 12,  having no idea that spring would be so chilly and slow here.  The picture shows the few blooms that have appeared.  The Magnolia bush behind the daffodils is usually in full bloom at this time. 

 

Monkey memory.

We now have the collapse of yet another supposed barrier between the minds of men and monkeys. It is known that monkeys can recognize pictures they have seen before (in experiments in which they are rewarded for doing so), but Basile and Hampton have devised a further behavioral protocol that let's them demonstrate recall, holding in mind an object without actually seeing it. Language is not necessary — either for having the ability to recall, or for proving it to an experimenter. Here is their abstract:

If you draw from memory a picture of the front of your childhood home, you will have demonstrated recall. You could also recognize this house upon seeing it. Unlike recognition, recall demonstrates memory for things that are not present. Recall is necessary for planning and imagining, and it can increase the flexibility of navigation, social behavior, and other cognitive skills. Without recall, memory is more limited to recognition of the immediate environment. Amnesic patients are impaired on recall tests, and recall performance often declines with aging. Despite its importance, we know relatively little about nonhuman animals' ability to recall information; we lack suitable recall tests for them and depend instead on recognition tests to measure nonhuman memory. Here we report that rhesus monkeys can recall simple shapes from memory and reproduce them on a touchscreen. As in humans , monkeys remembered less in recall than recognition tests, and their recall performance deteriorated more slowly. Transfer tests showed that monkeys used a flexible memory mechanism rather than memorizing specific actions for each shape. Observation of recall in Old World monkeys suggests that it has been adaptive for over 30 million years and does not depend on language.

Here is the basic protocol, as described by Nicholas Bakalar's NYTimes summary:

Researchers trained five rhesus monkeys. On a 5-by-5-inch grid on a computer screen, the monkeys were shown a shape consisting of three adjacent squares, one blue and two red in various patterns...After a moment, the red squares disappear, and the blue square moves to a different box on the grid. After another delay, the monkey has to restore the red squares to their original places in relation to the blue one by pressing on the correct boxes of the grid. When he does so successfully, he gets a food reward.

Increasing vanity in our culture.

John Tierney points to some fascinating work that looks at the lyrics of popular songs to assay our culture's increasing self absorption:

...after a computer analysis of three decades of hit songs, Dr. DeWall and other psychologists report finding what they were looking for: a statistically significant trend toward narcissism and hostility in popular music. As they hypothesized, the words “I” and “me” appear more frequently along with anger-related words, while there’s been a corresponding decline in “we” and “us” and the expression of positive emotions.

Last year, data from studies on nearly 50,000 students was subjected to a meta-analysis published in Social Psychological and Personality Science, that confirmed that narcissism has increased significantly in the past three decades. During this period, there have also been reports of higher levels of loneliness and depression

Healing anxiety disorders with cortisol

Around 6% of the adult population experiences some degree of acrophobia, strong anxiety and dizziness on exposure to, or anticipation of, a range of height-related situations. In some, but not all, people this condition can be ameliorated by behavioral therapy aimed at achieving habituation and eventual extinction of the phobic reaction by presenting them with the real or imagined phobic situation in a graduated way. de Quervain et al. show this therapy can be enhanced if a cortisol pill is taken one hour before a therapy session:

Behavioral exposure therapy of anxiety disorders is believed to rely on fear extinction. Because preclinical studies have shown that glucocorticoids can promote extinction processes, we aimed at investigating whether the administration of these hormones might be useful in enhancing exposure therapy. In a randomized, double-blind, placebo-controlled study, 40 patients with specific phobia for heights were treated with three sessions of exposure therapy using virtual reality exposure to heights. Cortisol (20 mg) or placebo was administered orally 1 h before each of the treatment sessions. Subjects returned for a posttreatment assessment 3–5 d after the last treatment session and for a follow-up assessment after 1 mo. Adding cortisol to exposure therapy resulted in a significantly greater reduction in fear of heights as measured with the acrophobia questionnaire (AQ) both at posttreatment and at follow-up, compared with placebo. Furthermore, subjects receiving cortisol showed a significantly greater reduction in acute anxiety during virtual exposure to a phobic situation at posttreatment and a significantly smaller exposure-induced increase in skin conductance level at follow-up. The present findings indicate that the administration of cortisol can enhance extinction-based psychotherapy.

Heartbeat synchrony between performer and crowd - emotional resonance

Amazing observations on the annual fire walking ritual in the Spanish village of San Pedro Manrique. Researchers were stymied in their efforts to measure physiological parameters such as blood pressure, cortisol levels, or pain tolerance in individuals as they were walking across a bed of hot coals, but were able to put heart rate monitors on both fire-walkers and spectators. It was a small study, monitoring heart rates of 12 fire-walkers, 9 spectators related to fire-walkers, and 17 unrelated spectators who were just visiting.

The heart rates of relatives and friends of the fire-walkers followed an almost identical pattern to the fire-walkers’ rates, spiking and dropping almost in synchrony. The heart rates of visiting spectators did not. The relatives’ rates synchronized throughout the event, which lasted 30 minutes, with 28 fire-walkers each making five-second walks. So relatives or friends’ heart rates matched a fire-walker’s rate before, during and after his walk. Even people related to other fire-walkers showed similar patterns.

This cohesion and solidarity happened in spectators who were simply watching, not sharing with performers the movements, vocalizations, or rhythms usually presumed to accompany social bonding through emotional resonance.  (added later...here is the PNAS article on this.)

Have your legal hearing just after the judge’s lunch break.

Fascinating observations by Danziger et al.:

Are judicial rulings based solely on laws and facts? Legal formalism holds that judges apply legal reasons to the facts of a case in a rational, mechanical, and deliberative manner. In contrast, legal realists argue that the rational application of legal reasons does not sufficiently explain the decisions of judges and that psychological, political, and social factors influence judicial rulings. We test the common caricature of realism that justice is “what the judge ate for breakfast” in sequential parole decisions made by experienced judges. We record the judges’ two daily food breaks, which result in segmenting the deliberations of the day into three distinct “decision sessions.” We find that the percentage of favorable rulings drops gradually from ≈65% to nearly zero within each decision session and returns abruptly to ≈65% after a break. Our findings suggest that judicial rulings can be swayed by extraneous variables that should have no bearing on legal decisions.

Physical pain and social rejection: same brain areas

This open access article by Kross et al. is well worth a look. It is a beautiful example of piggybacking a newer kind of human social emotion on top of brain area that originally evolved to deal with physical insults:

How similar are the experiences of social rejection and physical pain? Extant research suggests that a network of brain regions that support the affective but not the sensory components of physical pain underlie both experiences. Here we demonstrate that when rejection is powerfully elicited—by having people who recently experienced an unwanted break-up view a photograph of their ex-partner as they think about being rejected—areas that support the sensory components of physical pain (secondary somatosensory cortex; dorsal posterior insula) become active. We demonstrate the overlap between social rejection and physical pain in these areas by comparing both conditions in the same individuals using functional MRI. We further demonstrate the specificity of the secondary somatosensory cortex and dorsal posterior insula activity to physical pain by comparing activated locations in our study with a database of over 500 published studies. Activation in these regions was highly diagnostic of physical pain, with positive predictive values up to 88%. These results give new meaning to the idea that rejection “hurts.” They demonstrate that rejection and physical pain are similar not only in that they are both distressing—they share a common somatosensory representation as well.

"Evolving the I" a MindBlog lecture at the Univ. of Wisconsin

I thought I would pass on to MindBlog readers a a web version of the lecture I gave last Thursday to the Evolution Seminar Series at the Univ. of Wisconsin Madison where I am an Emeritus Professor. The title and topics:

Making Minds - Evolving and Constructing the “I”

I. Evolving brains.
The Beast Within
Mirroring
Varieties of “I”

II. Developing brains
Physical environment
Social environment

III. Modeling the subjective self:
The illusion of agency
The virtual machine and virtual organs
Emotions as evolved organs of consciousness

IV. Embodied cognition
Social emotions
Metaphor
Art and Music

V. Summary - the Self Illusion

Why old folks don’t sleep as well.

Older people have an earlier phase of everyday activity compared with the young. Not only is the consolidation of sleep and wake dramatically reduced, but overall circadian amplitude of hormones and body temperature are lower. Now Pagani et al. find that the biological clocks in cells taken from young and old people have the same periods, but they can be shortened by a heat labile factor in blood serum from older people. Identification of this factor might lead to development of drugs that block its action.:

Human aging is accompanied by dramatic changes in daily sleep–wake behavior: Activity shifts to an earlier phase, and the consolidation of sleep and wake is disturbed. Although this daily circadian rhythm is brain-controlled, its mechanism is encoded by cell-autonomous circadian clocks functioning in nearly every cell of the body. In fact, human clock properties measured in peripheral cells such as fibroblasts closely mimic those measured physiologically and behaviorally in the same subjects. To understand better the molecular mechanisms by which human aging affects circadian clocks, we characterized the clock properties of fibroblasts cultivated from dermal biopsies of young and older subjects. Fibroblast period length, amplitude, and phase were identical in the two groups even though behavior was not, thereby suggesting that basic clock properties of peripheral cells do not change during aging. Interestingly, measurement of the same cells in the presence of human serum from older donors shortened period length and advanced the phase of cellular circadian rhythms compared with treatment with serum from young subjects, indicating that a circulating factor might alter human chronotype. Further experiments demonstrated that this effect is caused by a thermolabile factor present in serum of older individuals. Thus, even though the molecular machinery of peripheral circadian clocks does not change with age, some age-related circadian dysfunction observed in vivo might be of hormonal origin and therefore might be pharmacologically remediable.

Yet another distortion of democracy.

An interesting study from Davis et al., on the effects of instantaneous polling while an election debate is proceeding:

A recent innovation in televised election debates is a continuous response measure (commonly referred to as the “worm”) that allows viewers to track the response of a sample of undecided voters in real-time. A potential danger of presenting such data is that it may prevent people from making independent evaluations. We report an experiment with 150 participants in which we manipulated the worm and superimposed it on a live broadcast of a UK election debate. The majority of viewers were unaware that the worm had been manipulated, and yet we were able to influence their perception of who won the debate, their choice of preferred prime minister, and their voting intentions. We argue that there is an urgent need to reconsider the simultaneous broadcast of average response data with televised election debates.

Religion and brain atrophy...

I guess I might as well continue the religion theme of yesterday's post with this piece from Owen et al., on religious factors and hippocampal atrophy in later life:

Despite a growing interest in the ways spiritual beliefs and practices are reflected in brain activity, there have been relatively few studies using neuroimaging data to assess potential relationships between religious factors and structural neuroanatomy. This study examined prospective relationships between religious factors and hippocampal volume change using high-resolution MRI data of a sample of 268 older adults. Religious factors assessed included life-changing religious experiences, spiritual practices, and religious group membership. Hippocampal volumes were analyzed using the GRID program, which is based on a manual point-counting method and allows for semi-automated determination of region of interest volumes. Significantly greater hippocampal atrophy was observed for participants reporting a life-changing religious experience. Significantly greater hippocampal atrophy was also observed from baseline to final assessment among born-again Protestants, Catholics, and those with no religious affiliation, compared with Protestants not identifying as born-again. These associations were not explained by psychosocial or demographic factors, or baseline cerebral volume. Hippocampal volume has been linked to clinical outcomes, such as depression, dementia, and Alzheimer's Disease. The findings of this study indicate that hippocampal atrophy in late life may be uniquely influenced by certain types of religious factors.

How to decrease belief in intelligent design

Tracy et al. make the encouraging observation that teaching existential meaning in naturalism can decrease belief in intelligent design. Their research:

...examined the psychological motives underlying widespread support for intelligent design theory (IDT), a purportedly scientific theory that lacks any scientific evidence; and antagonism toward evolutionary theory (ET), a theory supported by a large body of scientific evidence. We tested whether these attitudes are influenced by IDT's provision of an explanation of life's origins that better addresses existential concerns than ET. In four studies, existential threat (induced via reminders of participants' own mortality) increased acceptance of IDT and/or rejection of ET, regardless of participants' religion, religiosity, educational background, or preexisting attitude toward evolution. Effects were reversed by teaching participants that naturalism can be a source of existential meaning (see text clip of Dawkins' writing just below), and among natural-science students for whom ET may already provide existential meaning. These reversals suggest that the effect of heightened mortality awareness on attitudes toward ET and IDT is due to a desire to find greater meaning and purpose in science when existential threats are activated.

(sample clip from Dawkins: "It is very reasonable for humans to want to understand something of our context in a broader universe, awesome and vast. It is also reasonable for us to want to understand something about ourselves. And understanding the nature of the world and the nature of ourselves is, to a very major degree, I believe, what the human enterprise is about. Truth should be pursued, and science helps us pursue it; science gives us meaning.")

Liberal and Conservative brains

Greg Miller does a commentary on Kanai et al.'s study of correlations between political orientation and brain structure. The Kanai et al. abstract:

Highlights:

-Political liberalism and conservatism were correlated with brain structure
-Liberalism was associated with the gray matter volume of anterior cingulate cortex
-Conservatism was associated with increased right amygdala size
-Results offer possible accounts for cognitive styles of liberals and conservatives

Summary:

Substantial differences exist in the cognitive styles of liberals and conservatives on psychological measures [1]. Variability in political attitudes reflects genetic influences and their interaction with environmental factors [2,3]. Recent work has shown a correlation between liberalism and conflict-related activity measured by event-related potentials originating in the anterior cingulate cortex [4]. Here we show that this functional correlate of political attitudes has a counterpart in brain structure. In a large sample of young adults, we related self-reported political attitudes to gray matter volume using structural MRI. We found that greater liberalism was associated with increased gray matter volume in the anterior cingulate cortex, whereas greater conservatism was associated with increased volume of the right amygdala. These results were replicated in an independent sample of additional participants. Our findings extend previous observations that political attitudes reflect differences in self-regulatory conflict monitoring [4] and recognition of emotional faces [5] by showing that such attitudes are reflected in human brain structure. Although our data do not determine whether these regions play a causal role in the formation of political attitudes, they converge with previous work [4,6] to suggest a possible link between brain structure and psychological mechanisms that mediate political attitudes.

Multitasking compromises short term memory in seniors.

Sigh... A careful noting "by Clapp et al. of the "deficient ability to dynamically switch between functional brain networks" that I so clearly note in my 69 year old brain as I sit here in front of my new toy, an Apple 27" cinema display monitor I'm using to do four simultaneous tasks (and can't remember activities a few steps back when I switch to a different window) ..... Their basic observation is that people between the ages of 60 and 80 have significantly more trouble remembering tasks after experiencing a brief interruption than do people in their 20s and 30s.

Multitasking negatively influences the retention of information over brief periods of time. This impact of interference on working memory is exacerbated with normal aging. We used functional MRI to investigate the neural basis by which an interruption is more disruptive to working memory performance in older individuals. Younger and older adults engaged in delayed recognition tasks both with and without interruption by a secondary task. Behavioral analysis revealed that working memory performance was more impaired by interruptions in older compared with younger adults. Functional connectivity analyses showed that when interrupted, older adults disengaged from a memory maintenance network and reallocated attentional resources toward the interrupting stimulus in a manner consistent with younger adults. However, unlike younger individuals, older adults failed to both disengage from the interruption and reestablish functional connections associated with the disrupted memory network. These results suggest that multitasking leads to more significant working memory disruption in older adults because of an interruption recovery failure, manifest as a deficient ability to dynamically switch between functional brain networks.

Neuromarketing - not ready for prime time...

I don't usually react to emails suggesting that mindblog consider mentioning what turn out to be commercial sites, but I thought the points raised by Dan Hill in this article (PDF) were quite interesting, apart from the fact this his company, Sensory Logic, would like to sell your business their services on facial analysis of emotional reactions to stimuli or services. His contention is that facial coding, which follows the response of 43 facial muscles that signal emotion, is superior to other emotional monitors such as EMG (bio feedback), EEG (electrical activity on or just below the scalp), or fMRI (brain scans).

Juvenile training improves adult skills - at a cost.

Sarro and Sanes ask whether there are long-term effects of early sensory training that can only be assessed after maturation. The experiments examine auditory processing in gerbils and find that early training in detecting amplitude modulation yield adults with abilities superior to other animals trained as adults. This would probably hold for us humans, but you don't do conditioned avoidance experiments on human infants...

Sensory experience during development can modify the CNS and alter adult perceptual skills. While this principle draws support from deprivation or chronic stimulus exposure studies, the effect of training is addressed only in adults. Here, we asked whether a brief period of training during development can exert a unique impact on adult perceptual skills. Juvenile gerbils were trained to detect amplitude modulation (AM), a stimulus feature elemental to animal communication sounds. When the performance of these juvenile-trained animals was subsequently assessed in adulthood, it was superior to a control group that received an identical regimen of training as adults. The juvenile-trained animals displayed significantly better AM detection thresholds. This was not observed in an adult group that received only exposure to AM stimuli as juveniles. To determine whether enhanced adult performance was due solely to learning the conditioned avoidance procedure, juveniles were trained on frequency modulation (FM) detection, and subsequently assessed on AM detection as adults. These animals displayed significantly poorer AM detection thresholds than all other groups. Thus, training on a specific auditory task (AM detection) during development provided a benefit to performance on that task in adulthood, whereas an identical training regimen in adulthood did not bring about this enhancement. In contrast, there was a cost, in adulthood, following developmental training on a different task (FM detection). Together, the results demonstrate a period of heightened sensitivity in the developing CNS such that behavioral training in juveniles has a unique impact on adult behavioral capabilities.

Pain reduction by mindfulness meditation - brain correlates

Zeidan et al. offer these interesting results on possible consequences of a form of mindfulness meditation called Shamatha, or focused attention, which is a cognitive practice of sustaining attention on the changing sensations of the breath, monitoring discursive events as they arise, disengaging from those events without affective reaction, and redirecting attention back to the breath. Slightly edited clips from the abstract:

The subjective experience of one's environment is constructed by interactions among sensory, cognitive, and affective processes. For centuries, meditation has been thought to influence such processes by enabling a nonevaluative representation of sensory events. To better understand how meditation influences the sensory experience, we used arterial spin labeling functional magnetic resonance imaging to assess the neural mechanisms by which mindfulness meditation influences pain in healthy human participants. After 4 d of mindfulness meditation training, meditating in the presence of noxious stimulation significantly reduced pain unpleasantness by 57% and pain intensity ratings by 40% when compared to rest... Meditation reduced pain-related activation of the contralateral primary somatosensory cortex [note: the noxious stimulus was a thermal stimulator placed on the rear right calf, and thus would be reported to the left (contralateral) somatosensory cortex]...Meditation-induced reductions in pain intensity ratings were associated with increased activity in the anterior cingulate cortex and anterior insula, areas involved in the cognitive regulation of nociceptive (pain) processing. Reductions in pain unpleasantness ratings were associated with orbitofrontal cortex activation, an area implicated in reframing the contextual evaluation of sensory events. Moreover, reductions in pain unpleasantness also were associated with thalamic deactivation, which may reflect a limbic gating mechanism involved in modifying interactions between afferent input and executive-order brain areas. Together, these data indicate that meditation engages multiple brain mechanisms that alter the construction of the subjectively available pain experience from afferent (incoming) information.

Self control makes us angry

In several different places I have come across this interesting article by Gal and Liu. Exerting self control is usually assoicated with positive emotions and wellbeing, but some research has also shown that exerting self control can lead to increased aggression. The authors:

...find that exerting self control is associated with angry behavior more broadly. In particular, using a “matched-choice paradigm,” we find that after exerting self control people exhibit increased preference for anger-themed content, greater interest in faces exhibiting anger, greater endorsement of anger-framed appeals, and greater irritation to others‟ attempts to control one‟s behavior.

The authors note that because the anger-related behaviors examined in their experiments are not inappropriate, they are unlikely to reflect diminished capacities of self-regulation. Three of the several possible reasons why exerting self-control might elicit (implicit) anger they list are:

Goal Frustration - primitive and evolutionary roots drive angry facial expressions and the autonomic response of facial flushing in a newborn baby when a sucking treat is removed.

Diminished sense of Autonomy - anger from the sense that one‟s sense of freedom is restricted and that one is "forced" to choose the virtuous path rather than indulgence.

Ego depletion - the state of being depleted (not having the short term goal deferred for the long term goal) makes people angry.