Friday, April 29, 2011

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.

Thursday, April 28, 2011

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.

Wednesday, April 27, 2011

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.")

Tuesday, April 26, 2011

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.

Monday, April 25, 2011

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.

Friday, April 22, 2011

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).

Thursday, April 21, 2011

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.

Wednesday, April 20, 2011

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.

Tuesday, April 19, 2011

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.

Monday, April 18, 2011

Dialing numbers on your cellphone can elicit concepts

Observations by Topolinski note an interesting consequence of our cell phone habits:

When people perform actions, effects associated with the actions are activated mentally, even if those effects are not apparent. This study tested whether sequences of simulations of virtual action effects can be integrated into a meaning of their own. Cell phones were used to test this hypothesis because pressing a key on a phone is habitually associated with both digits (dialing numbers) and letters (typing text messages).  In the first experiment, dialing digit sequences induced the meaning of words that share the same key sequence (e.g., 5683, LOVE). This occurred even though the letters were not labeled on the keypad, and participants were not aware of the digit-letter correspondences. In a second experiment, subjects preferred dialing numbers implying positive words (e.g., 37326, DREAM) over dialing numbers implying negative words (e.g., 75463, SLIME). Finally, subjects preferred companies with phone numbers implying a company-related word (e.g., LOVE for a dating agency, CORPSE for a mortician) compared with companies with phone numbers implying a company-unrelated word.

Friday, April 15, 2011

Outsourcing self regulation

It seems reasonable that thinking about supportive partners should be motivationally bolstering - leading us to work harder. Fitzsimonds and Finkel make observations that suggest just the opposite - that such thoughts are motivationally undermining, causing us to make less ambitious plans to pursue goals and to spend less time on the pursuit.
The their first experiment,

...participants who thought about how their partner helped them with health goals (as opposed to career goals) planned to spend less time and effort on health goals in the upcoming week. This pattern was stronger for depleted participants than for nondepleted participants.
In a second experiment,
...participants who thought about how their partner helped them with academic-achievement goals procrastinated more, leaving themselves less time for an academic task, than did participants in two control conditions. This pattern was stronger for participants who were told that procrastinating would drain their resources for the academic task than for participants who were told that procrastinating would not drain their resources for that task.
A final experiment
...found that participants who decreased their effort after thinking of an instrumental significant other reported higher relationship commitment to that individual than did participants who did not decrease their effort.
The authors suggest that:
...partners may develop shared self-regulatory systems, or “transactive self-control,” relying on each other for help with self-control. Individuals who rely on their romantic partner for help with self-control in one area may be able to conserve valuable resources for other goal pursuits. If so, such a shared self-regulatory system—although it could ironically undermine short-term outcomes, as in the case of the outsourcing phenomenon shown here—could ultimately benefit partners if it allowed them to best make use of their limited self-control resources over time.

Thursday, April 14, 2011

A long, diligent life...

Lagergren reviews Friedman and Martin's recent book on the 8-decade long longevity study started in 1921 at Stanford University by Lewis Terman, which has followed the histories of 1,500 gifted children from schools in the state and followed them from the age of 11 into adulthood, collecting a variety of data to see what might predict later success and accomplishment. The recent update collects information on those who have died.

Some results are as expected, such as that smoking is bad for longevity. Others turn conventional wisdom on its head...working hard for long hours in a demanding job to achieve high status is better for your health and life expectancy than taking it easy and lacking ambition. Marriage is a blessing for men more than women; and men suffer more adverse health effects from divorce, perhaps turning to drink or drugs. The authors emphasize the benefits of an active social network — more common for women — as a buffer against life's harmful events. And they are critical of simple health advice, such as to jog or eat less fat, arguing that it is the whole approach to life that is essential, not the details. To give a person a list of health recommendations does not work, they point out, if the person cannot or does not follow them.

The best predictor of a long and healthy life turned out to be conscientiousness — the extent to which a child was prudent, dependable and persistent in the accomplishment of his or her goals...You do not become conscientious overnight. It is the long-term, determined work of adopting and sticking to healthy habits and seeking good social environments and relationships that makes the difference. Later follow-up of Terman's subjects showed that conscientiousness in middle age and later counts almost as much as in childhood... Conscientious people do more to protect their health and are less likely to engage in risky activities such as smoking, drinking or drug-taking, the study found. They also find their way to happier marriages, better friendships and optimum work situations. As a result, they are less likely to die from all causes...

Being physically active as a child is also a predictor of longevity, but only if that activity is maintained into and beyond middle age. The life-years gained by jogging may amount to no more than the time you spend doing it, the authors note. So we needn't all aim to run marathons; rather, we should just maintain an activity that we enjoy.

Wednesday, April 13, 2011

Disorder promotes discrimination and stereotyping

Stapel and Lindenberg find that environmental signs of disorder, such as uncollected trash at a train station or cars parked askew on a sidewalk, are sufficient to induce bystanders to desire orderliness. The consequences are that these bystanders elect to sit further from minorities when asked to fill in a survey and donated less of their payments (for participating in the survey) to help immigrants and the homeless. The desire for order is fulfilled by an increased propensity toward classification, which includes stereotyping. [One field study used the Utrecht train hub in the middle of the Netherlands, where thousands of travelers pass through on a daily basis. During a cleaners’ strike, the train station quickly turned into a dirty and disordered environment. After the station had not been cleaned for a few days in a row, the authors asked 40 travelers who were waiting for their train to participate in their study in return for a candy bar or an apple. They were asked to judge the extent to which they thought certain traits applied to a particular group (in their case, Muslims, homosexuals, and the Dutch). The laboratory experiments, where behaviors after pictures of order versus disorder were used, employed 40-70 subjects.]. Here is their abstract:

Being the victim of discrimination can have serious negative health- and quality-of-life–related consequences. Yet, could being discriminated against depend on such seemingly trivial matters as garbage on the streets? In this study, we show, in two field experiments, that disordered contexts (such as litter or a broken-up sidewalk and an abandoned bicycle) indeed promote stereotyping and discrimination in real-world situations and, in three lab experiments, that it is a heightened need for structure that mediates these effects (number of subjects: between 40 and 70 per experiment). These findings considerably advance our knowledge of the impact of the physical environment on stereotyping and discrimination and have clear policy implications: Diagnose environmental disorder early and intervene immediately.

Tuesday, April 12, 2011

Hurt the flesh, cleanse the soul....

Here are some summary, slightly edited, clips from an interesting study by Bastian et al. (performed on the usual batch of college undergraduates, paid $10 for their participation in the study):

Pain purifies. History is replete with examples of ritualized or self-inflicted pain aimed at achieving purification...When reminded of an immoral deed, people are motivated to experience physical pain. Student participants in the study who wrote about an unethical behavior not only held their hands in ice water longer but also rated the experience as more painful than did participants who wrote about an everyday interaction. Critically, experiencing pain reduced people’s feelings of guilt, and the effect of the painful task on ratings of guilt was greater than the effect of a similar but nonpainful task.

Pain has traditionally been understood as purely physical in nature, but it is more accurate to describe it as the intersection of body, mind, and culture. People give meaning to pain, and we argue that people interpret pain within a judicial model of pain as punishment. Our results suggest that the experience of pain has psychological currency in rebalancing the scales of justice—an interpretation of pain that is analogous to notions of retributive justice. Interpreted in this way, pain has the capacity to resolve guilt.

People are socialized to understand pain within this judicial framework. Physical pain is employed as a penalty (e.g., spanking children for misbehavior), and unexplained pain is often understood as punishment from God. The judicial model is explicit in the Latin word for pain, poena, which means “to pay the penalty.” Understood this way, pain may be perceived as repayment for sin in three ways. First, pain is the embodiment of atonement. Just as physical cleansing washes away sin, physical pain is experienced as a penalty, and paying that penalty reestablishes moral purity. Second, subjecting oneself to pain communicates remorse to others (including God) and signals that one has paid for one’s sins, and this removes the threat of external punishment. Third, tolerating the punishment of pain is a test of one’s virtue, reaffirming one’s positive identity to oneself and others.

Previous work has demonstrated that giving meaning to pain affects people’s management of that pain. By introducing the judicial model of pain, we emphasize that giving meaning to pain can also affect other psychological processes. Although additional research is needed, our findings demonstrate that experiencing pain as a penalty can cause people to feel that their guilt is resolved and their soul cleansed.

Monday, April 11, 2011

Improving your cognitive toolkit - VII

Continuation of my sampling of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":
Alun Anderson - Homo Dilatus

Our species might well be renamed Homo Dilatus, the procrastinating ape. Somewhere in our evolution we acquired the brain circuitry to deal with sudden crises and respond with urgent action. Steady declines and slowly developing threats are quite different. "Why act now when the future is far off," is the maxim for a species designed to deal with near-term problems and not long term uncertainties. It's a handy view of humankind which everyone who uses science to change policy should keep in their mental took kit, and one that that is greatly reinforced by the endless procrastination in tacking climate change. Cancun follows Copenhagen follows Kyoto but the more we dither and no extraordinary disaster follows, the more dithering seems just fine.

Such behaviour is not unique to climate change. It took the sinking of the Titanic to put sufficient life boats on passenger ships, the huge spill from the Amoco Cadiz to set international marine pollution rules and the Exxon Valdez disaster to drive the switch to double-hulled tankers. The same pattern is seen in the oil industry, with the Gulf spill the latest chapter in the disaster first-regulations later mindset of Homo dilatus.
Geoffrey Miller - Personality traits are continuous with mental illnesses
Our instinctive way of thinking about insanity — our intuitive psychiatry — is dead wrong... There's a scientific consensus that personality traits can be well-described by five main dimensions of variation. These "Big Five" personality traits are called openness, conscientiousness, extraversion, agreeableness, and emotional stability. The Big Five are all normally distributed in a bell curve, statistically independent of each other, genetically heritable, stable across the life-course, unconsciously judged when choosing mates or friends, and found in other species such as chimpanzees. They predict a wide range of behavior in school, work, marriage, parenting, crime, economics, and politics.

Mental disorders are often associated with maladaptive extremes of the Big Five traits. Over-conscientiousness predicts obsessive-compulsive disorder, whereas low conscientiousness predicts drug addiction and other "impulse control disorders". Low emotional stability predicts depression, anxiety, bipolar, borderline, and histrionic disorders. Low extraversion predicts avoidant and schizoid personality disorders. Low agreeableness predicts psychopathy and paranoid personality disorder. High openness is on a continuum with schizotypy and schizophrenia. Twin studies show that these links between personality traits and mental illnesses exist not just at the behavioral level, but at the genetic level. And parents who are somewhat extreme on a personality trait are much more likely to have a child with the associated mental illness.

Friday, April 08, 2011

Music and language - differing brain activations

Rogalsky et al. obtain data that fills out in much more detail a description of which brain activations overlap and which differ during the processing of speech versus music. Here is their abstract, following by a figure from the paper:

Language and music exhibit similar acoustic and structural properties, and both appear to be uniquely human. Several recent studies suggest that speech and music perception recruit shared computational systems, and a common substrate in Broca's area for hierarchical processing has recently been proposed. However, this claim has not been tested by directly comparing the spatial distribution of activations to speech and music processing within subjects. In the present study, participants listened to sentences, scrambled sentences, and novel melodies. As expected, large swaths of activation for both sentences and melodies were found bilaterally in the superior temporal lobe, overlapping in portions of auditory cortex. However, substantial nonoverlap was also found: sentences elicited more ventrolateral activation, whereas the melodies elicited a more dorsomedial pattern, extending into the parietal lobe. Multivariate pattern classification analyses indicate that even within the regions of blood oxygenation level-dependent response overlap, speech and music elicit distinguishable patterns of activation. Regions involved in processing hierarchical aspects of sentence perception were identified by contrasting sentences with scrambled sentences, revealing a bilateral temporal lobe network. Music perception showed no overlap whatsoever with this network. Broca's area was not robustly activated by any stimulus type. Overall, these findings suggest that basic hierarchical processing for music and speech recruits distinct cortical networks, neither of which involves Broca's area. We suggest that previous claims are based on data from tasks that tap higher-order cognitive processes, such as working memory and/or cognitive control, which can operate in both speech and music domains.

Figure - regions selective for speech versus music. Speech stimuli selectively activates more lateral regions in the superior temporal lobe bilaterally, while music stimuli selectively activate more medial anterior regions on the supratemporal plane and extending into the insula, primarily in the right hemisphere. (This apparently lateralized pattern for music does not mean that the right hemisphere preferentially processes music stimuli as is often assumed. An analysis in the paper also shows that music activates both hemispheres rather symmetrically; the lateralization effect is in the relative activation patterns to music versus speech.)

Thursday, April 07, 2011

Elephants know when they need a helping trunk.

From de Waal and collaborators, evidence for convergent evolution of cooperation:

Elephants are widely assumed to be among the most cognitively advanced animals, even though systematic evidence is lacking. This void in knowledge is mainly due to the danger and difficulty of submitting the largest land animal to behavioral experiments. In an attempt to change this situation, a classical 1930s cooperation paradigm commonly tested on monkeys and apes was modified by using a procedure originally designed for chimpanzees (Pan troglodytes) to measure the reactions of Asian elephants (Elephas maximus). This paradigm explores the cognition underlying coordination toward a shared goal. What do animals know or learn about the benefits of cooperation? Can they learn critical elements of a partner's role in cooperation? Whereas observations in nature suggest such understanding in nonhuman primates, experimental results have been mixed, and little evidence exists with regards to nonprimates. Here, we show that elephants can learn to coordinate with a partner in a task requiring two individuals to simultaneously pull two ends of the same rope to obtain a reward. Not only did the elephants act together, they inhibited the pulling response for up to 45 s if the arrival of a partner was delayed. They also grasped that there was no point to pulling if the partner lacked access to the rope. Such results have been interpreted as demonstrating an understanding of cooperation. Through convergent evolution, elephants may have reached a cooperative skill level on a par with that of chimpanzees.

Wednesday, April 06, 2011

The brains of experts - due to predispositions and/or training?

Here is how Golestant et al. frame their interesting study on the brains of expert Phoneticians - who typically spend one to four years of formal training learning to identify speech sounds and to transcribe them into an international phonetic alphabet. (Remember, you can view any of the brain structures they mention by simply entering their name in Google Image Search.) The work suggests that morphological brain differences at birth might well influence career choices. We tend to enjoy and get reinforcement for doing things we are good at. (I've always wondered about a brain correlate for my ability, from a young age, to sight read any piece of sheet music put in front of me.)

Expertise has been shown to have both functional and structural correlates in the human brain. For example, expert golfers show a different pattern of neural activity than novice golfers when planning shots, and London taxi drivers have a larger posterior hippocampal volume than matched controls. It can be difficult to establish, however, the extent to which these effects relate to preexisting differences between the novice and expert groups, or whether these effects mainly arise from training-induced plasticity. Here we investigate brain anatomy in expert phoneticians...to distinguish experience-dependent plasticity from brain structural features that existed before the onset of expertise training.
From their abstract:
...We found a positive correlation between the size of left pars opercularis and years of phonetic transcription training experience, illustrating how learning may affect brain structure. Phoneticians were also more likely to have multiple or split left transverse gyri in the auditory cortex than nonexpert controls, and the amount of phonetic transcription training did not predict auditory cortex morphology. The transverse gyri are thought to be established in utero; our results thus suggest that this gross morphological difference may have existed before the onset of phonetic training, and that its presence confers an advantage of sufficient magnitude to affect career choices. These results suggest complementary influences of domain-specific predispositions and experience-dependent brain malleability, influences that likely interact in determining not only how experience shapes the human brain but also why some individuals become engaged by certain fields of expertise.

Tuesday, April 05, 2011

Competitions for memory, it's stabilization, and a memory enhancer

Kuhl et al. find that the competition in the brain between old memories and new ones that are associated with the same thing (for example, an old versus a new password, or yesterday's versus today's space in the parking lot) can be observed in fMRI. They found competition between visual memories was captured in the relative degree to which target vs. competing memories were reactivated within the ventral occipitotemporal cortex. When lowered VOTC reactivation indicated that conflict between target and competing memories was high, frontoparietal mechanisms were markedly engaged, revealing specific neural mechanisms that tracked competing mnemonic evidence.

In another study on memory Diekelmann et al. show that memory reactivation has opposing effects on memory stability during wakefulness and sleep. Reactivation during slow-wave sleep following learning can stabilize memories. Reactivation during wakefulness has the opposite effect, rendering memories labile and susceptible to modest modification.

Finally Benedict Carey points to a study by Shema et al. showing that increasing levels of a brain enzyme (a protein kinase C isoform) involved in memory formation enhances long term memory. Also, Chen et al. show that injections of a different protein, a growth factor involved in memory formation (insulin-like growth factor II) can have the same effect.

Monday, April 04, 2011

Increasing the viewed size of a painful body part reduces the pain

Here's an interesting and useful bit from Mancini et al.:

Pain is a complex subjective experience that is shaped by numerous contextual factors. For example, simply viewing the body reduces the reported intensity of acute physical pain. In this study, we investigated whether this visually induced analgesia is modulated by the visual size of the stimulated body part. We measured contact heat-pain thresholds while participants viewed either their own hand or a neutral object in three size conditions: reduced, actual size, or enlarged. Vision of the body was analgesic, increasing heat-pain thresholds by an average of 3.2 °C. We further found that visual enlargement of the viewed hand enhanced analgesia, whereas visual reduction of the hand decreased analgesia. These results demonstrate that pain perception depends on multisensory representations of the body and that visual distortions of body size modulate sensory components of pain.

Saturday, April 02, 2011

Dynamic Views of Mindblog

I just pulled up the Blogger edit postings page for this blog and up pops a message "Did you know that...."

Turns out they have now added "Dynamic Views" - different ways of viewing a blog (flipcard, mosaic, sidebar, and timeslide...snapshot does not work for MindBlog) Click on the Dynamic Views of MindBlog link at the upper right to view several different viewing options.

Friday, April 01, 2011

A bad taste in the mouth - more on embodied cognition and emotion

Eskine et al. provide yet another example of how emotion induced by a physical stimulus can influence a moral stance. (Previous mindblog postings have noted this effect for hard/soft or rough/smooth surfaces, hot/cold temperature stimuli, clean/dirty smells or visual images, etc.) The experimental subjects were the usual captive college psychology course undergraduates (54 of them in this case):

Can sweet-tasting substances trigger kind, favorable judgments about other people? What about substances that are disgusting and bitter? Various studies have linked physical disgust to moral disgust, but despite the rich and sometimes striking findings these studies have yielded, no research has explored morality in conjunction with taste, which can vary greatly and may differentially affect cognition. The research reported here tested the effects of taste perception on moral judgments. After consuming a sweet beverage, a bitter beverage, or water, participants rated a variety of moral transgressions. Results showed that taste perception significantly affected moral judgments, such that physical disgust (induced via a bitter taste) elicited feelings of moral disgust. Further, this effect was more pronounced in participants with politically conservative views than in participants with politically liberal views. Taken together, these differential findings suggest that embodied gustatory experiences may affect moral processing more than previously thought.