Our pupil dilation reflects decision related choice.

Pupil size is known to be increased by effortful decisions. The current supposition is that decision-related pupil dilation tracks the activity of neuromodulatory systems of the brainstem—in particular, the noradrenergic locus coeruleus and, possibly the cholinergic basal forebrain systems. These neuromodulatory systems activate briefly during perceptual decisions such as visual target detection.

de Gee et al. now provide evidence that pupil dilation reflects not the termination of the decision process but rather events during the course of decision formation. The amplitude of pupil dilation is bigger during decision formation for yes than for no choices, and it is strongest in conservative subjects choosing yes against their bias. Imagine what advertisers or merchandizers training cameras on their customers might be able to do with this!

A number of studies have shown that pupil size increases transiently during effortful decisions. These decision-related changes in pupil size are mediated by central neuromodulatory systems, which also influence the internal state of brain regions engaged in decision making. It has been proposed that pupil-linked neuromodulatory systems are activated by the termination of decision processes, and, consequently, that these systems primarily affect the postdecisional brain state. Here, we present pupil results that run contrary to this proposal, suggesting an important intradecisional role. We measured pupil size while subjects formed protracted decisions about the presence or absence (“yes” vs. “no”) of a visual contrast signal embedded in dynamic noise. Linear systems analysis revealed that the pupil was significantly driven by a sustained input throughout the course of the decision formation. This sustained component was larger than the transient component during the final choice (indicated by button press). The overall amplitude of pupil dilation during decision formation was bigger before yes than no choices, irrespective of the physical presence of the target signal. Remarkably, the magnitude of this pupil choice effect (yes > no) reflected the individual criterion: it was strongest in conservative subjects choosing yes against their bias. We conclude that the central neuromodulatory systems controlling pupil size are continuously engaged during decision formation in a way that reveals how the upcoming choice relates to the decision maker’s attitude. Changes in brain state seem to interact with biased decision making in the face of uncertainty.

Reaction time and longevity.

Hagger-Johnson et al. note a correlation between reaction times (doing a button press as quickly as possible after a light flashes on a computer screen) and mortality in 5,145 adults ages 20 to 59 (measured in the late 1980s and early ’90s). The subjects were followed to see how many would be alive after 15 years. After controlling for smoking, drinking, and other factors, the authors found that those with slower reaction times (one standard deviation less than average) were 25 percent more likely to die of any cause, and 36 percent more likely to die of cardiovascular disease, than those with faster reactions. There was no correlation with cancer deaths. The reasons for the statistical correlation is not clear, but the obvious idea is that slower reaction times may reflect brain or nervous system problems that increase morbidity.

Genetic predisposition of our behavioral responses.

Gregory sets the context for a recent article by Skuze et al. on how genes for our oxytocin receptors can influence our social recognition skills:

...the notion that the evolution of our behavioral response is solely shaped by the events themselves is challenged by studies that highlight how interindividual differences in social perception and response to social cues may be determined by underlying genetic predisposition. These studies are establishing that our DNA contains heritable variants that contribute to subtle differences in social cognition. These sequence variants are contained within genes that not only play a role in the relationship that parents may have with their offspring but also how we recognize or react to one another. In PNAS, Skuse et al.investigate the signaling pathways of neuropeptides oxytocin (OT) and arginine-vasopressin (AVP) to identify DNA polymorphisms that might explain interindividual differences in response to social cues. The authors genotyped a series of SNPs from the OT and AVP receptor regions to identify SNPs that account for variation in response to tests of social cognition in autism spectrum disorder (ASD) families.

Here is the Skuze et al. abstract:

The neuropeptides oxytocin and vasopressin are evolutionarily conserved regulators of social perception and behavior. Evidence is building that they are critically involved in the development of social recognition skills within rodent species, primates, and humans. We investigated whether common polymorphisms in the genes encoding the oxytocin and vasopressin 1a receptors influence social memory for faces. Our sample comprised 198 families, from the United Kingdom and Finland, in whom a single child had been diagnosed with high-functioning autism. Previous research has shown that impaired social perception, characteristic of autism, extends to the first-degree relatives of autistic individuals, implying heritable risk. Assessments of face recognition memory, discrimination of facial emotions, and direction of gaze detection were standardized for age (7–60 y) and sex. A common SNP (single nucleotide polymorphism) in the oxytocin receptor (rs237887) was strongly associated with recognition memory in combined probands, parents, and siblings after correction for multiple comparisons. Homozygotes for the ancestral A allele had impairments in the range −0.6 to −1.15 SD scores, irrespective of their diagnostic status. Our findings imply that a critical role for the oxytocin system in social recognition has been conserved across perceptual boundaries through evolution, from olfaction in rodents to visual memory in humans.

Different cultures, different computation systems

Bender and Beller report that a mixed number system superimposing three binary steps onto a decimal structure was invented long before Leibniz’s description of binary numerals, for easier calculations to measure mixed quantities of yams and other garden products, on the Pacific island of Mangareva. It did not arise on other islands of the Pacific with similar ecologies.

...the mixed counting system in Mangarevan...is unique in that it had three binary steps superposed onto a decimal structure. In showing how these steps affect calculation, our analysis yields important insights for theorizing on numerical cognition: counting systems serve as complex cultural tools for numerical cognition, apparently unwieldy systems may in fact be cognitively advantageous, and such advantageous systems can be—and have been—developed by nonindustrialized societies and in the absence of notational systems. These insights also help to dismiss simple notions of cultural complexity as a homogenous state and emphasize that investigating cultural diversity is not merely an optional extra, but a must.

From their conclusions:

Summarizing our results, it seems clear that superposing a decimal system with binary steps is indeed advantageous, as described by Leibniz because it allows arduous calculations and retrieval of addition facts to be replaced by simple transformations in the binary range. Crucially, these advantages are not vitiated by the downside of longer number representations also anticipated by Leibniz. The decimal basis of the system guarantees that number representations remain relatively compact. The mixed system thus neutralizes the tradeoff associated with base size by combining the benefits of a small base (fewer or no addition facts) with the benefits of a larger base (compact representation). Actually, both of these implications adjust to the constraints on working memory and thereby benefit mental arithmetic: the more compact representation relieves cognitive load in retaining information, and the reduction in addition facts relieves cognitive load in processing. The main cost inflicted by this mixing is an increase in irregularity, which requires additional lexemes and rules and thus affects the ease with which a system is learned and mastered....Apparently, its users favored the benefits of the mixed system over the regularity of the general decimal system, as they developed the mixed system out of the purely decimal system in wide use across Polynesia.

Why electroconvulsive therapy works in mood disorders.

Dukart et al. make the interesting observation that the controversial procedure of electroconvulsive therapy causes changes in gray matter volume in the brain areas that are implicated as abnormal in refractory major depression and manic depression:

There remains much scientific, clinical, and ethical controversy concerning the use of electroconvulsive therapy (ECT) for psychiatric disorders stemming from a lack of information and knowledge about how such treatment might work, given its nonspecific and spatially unfocused nature. The mode of action of ECT has even been ascribed to a “barbaric” form of placebo effect. Here we show differential, highly specific, spatially distributed effects of ECT on regional brain structure in two populations: patients with unipolar or bipolar disorder. Unipolar and bipolar disorders respond differentially to ECT and the associated local brain-volume changes, which occur in areas previously associated with these diseases, correlate with symptom severity and the therapeutic effect. Our unique evidence shows that electrophysical therapeutic effects, although applied generally, take on regional significance through interactions with brain pathophysiology.

Constancy of our social signatures.

Robin Dunbar and collaborators have done an interesting examination of the persistence of how many close contacts we maintain (family and close friends) over time, even as the identities of those who are close to us changes. Dunbar is the guy who is well known for his early work showing a correlation between the brain size of social mammals and the size of their social groups. His line relating brain size to group size put the maximal or optimal size of human groups at about 150 individuals. (Enter 'Dunbar' in the search box to the left to see several MindBlog posts on his work.) Here are some clips from their article.

...It appears that having strong and supportive relationships, characterized by closeness and emotional intensity, is essential for health and well-being in both humans and other primates. At the same time, there is a higher cost to maintaining closer relationships, reflected in the amount of effort required to maintain a relation at the desired level of emotional closeness. Because of this, the number of emotionally intense relationships is typically small. Moreover, it has been suggested that ego networks, the sets of ties individuals (egos) have to their friends and family (alters), may be subject to more general constraints associated with limits on human abilities to interact with large numbers of alters. Although there are obvious constraints on the time available for interactions, additional constraints may also arise through limits on memory capacity or other cognitive abilities.

..it is reasonable to ask whether such mechanisms shape these networks in similar ways under different circumstances, giving rise to some characteristic features that persist over time despite network turnover...We combine detailed, autorecorded data from mobile phone call records with survey data. These were collected during a study that tracked changes in the ego networks of 24 students over 18 mo as they made the transition from school to university or work. These changes in personal circumstances result in a period of flux for the social relationships of the participants, with many alters both leaving and entering their networks. This provides a unique setting for studying network-level structure and its response to major changes in social circumstances.

Our results establish three unique findings: (i) There is a consistent, broad, and robust pattern in the way people allocate their communication across the members of their social network, with a small number of top-ranked, emotionally close alters receiving a disproportionately large fraction of calls; (ii) within this general pattern, there is clear individual-level variation so that each individual has a characteristic social signature depicting his or her particular way of communication allocation; and (iii) this individual social signature remains stable and retains its characteristic shape over time and is only weakly affected by network turnover. Thus, individuals appear to differ in how they allocate their available time to their alters, irrespective of who these alters are. Further, our subsidiary analyses (SI Text) suggest that this finding applies not just to call frequencies, because the frequency of calls to an alter correlates with emotional closeness and frequency of face-to-face interactions.

Here is their summary abstract:

We combine cell phone data with survey responses to show that a person’s social signature, as we call the pattern of their interactions with different friends and family members, is remarkably robust. People focus a high proportion of their communication efforts on a small number of individuals, and this behavior persists even when there are changes in the identity of the individuals involved. Although social signatures vary between individuals, a given individual appears to retain a specific social signature over time. Our results are likely to reflect limitations in the ability of humans to maintain many emotionally close relationships, both because of limited time and because the emotional “capital” that individuals can allocate between family members and friends is finite.

Does music make you smarter?

Since I have done a number of posts on long term changes in the brains of adults who have had extensive music training, I thought I should point at an article by Samuel Mehr in the NYTimes that is essentially relaying the results of a study he and his collaborators published in PLOS ONE. Wanting to evaluate reported associations between children's participation in music classes and better grades, higher SAT scores and elevated cognitive skills,they note that correlations are not causes, and do several short term studies on the cognitive effects of a brief series of music classes, compared to non-musical forms of arts instructions. The bottom line was that in two trials, with 29 and 45 preschoolers randomly assigned to music or visual arts classes, they found no evidence that parent-child music classes improved preschoolers' cognitive skills. These brief interventions, studying a limited number of subjects, would need to be repeated to be confirmed, and in any case cast no light on light whether more continuous and rigorous instruction in musical performance correlates with cognitive or brain anatomical changes. Here is their abstract:

Young children regularly engage in musical activities, but the effects of early music education on children's cognitive development are unknown. While some studies have found associations between musical training in childhood and later nonmusical cognitive outcomes, few randomized controlled trials (RCTs) have been employed to assess causal effects of music lessons on child cognition and no clear pattern of results has emerged. We conducted two RCTs with preschool children investigating the cognitive effects of a brief series of music classes, as compared to a similar but non-musical form of arts instruction (visual arts classes, Experiment 1) or to a no-treatment control (Experiment 2). Consistent with typical preschool arts enrichment programs, parents attended classes with their children, participating in a variety of developmentally appropriate arts activities. After six weeks of class, we assessed children's skills in four distinct cognitive areas in which older arts-trained students have been reported to excel: spatial-navigational reasoning, visual form analysis, numerical discrimination, and receptive vocabulary. We initially found that children from the music class showed greater spatial-navigational ability than did children from the visual arts class, while children from the visual arts class showed greater visual form analysis ability than children from the music class (Experiment 1). However, a partial replication attempt comparing music training to a no-treatment control failed to confirm these findings (Experiment 2), and the combined results of the two experiments were negative: overall, children provided with music classes performed no better than those with visual arts or no classes on any assessment. Our findings underscore the need for replication in RCTs, and suggest caution in interpreting the positive findings from past studies of cognitive effects of music instruction.

When psychotherapy works - what are the brain changes?

The journal Brain and Behavioral Science circulates forthcoming articles for peer commentary before their final publication in the journal. I thought I would pass on the abstract of such an article by Lane et al., who propose that the essential ingredients in therapeutic change include: 1) reactivating old memories; 2) engaging in new emotional experiences that are incorporated into these reactivated memories via the process of reconsolidation; and 3) reinforcing the integrative memory structure by practicing a new way of behaving and experiencing the world in a variety of contexts.

Memory Reconsolidation, Emotional Arousal and the Process of Change in Psychotherapy: New Insights from Brain Science

Richard D. Lane, Lee Ryan, Lynn Nadel, and Leslie Greenberg

Abstract: Since Freud clinicians have understood that disturbing memories contribute to psychopathology and that new emotional experiences contribute to therapeutic change. Yet, controversy remains about what is truly essential to bring about psychotherapeutic change. Mounting evidence from empirical studies suggests that emotional arousal is a key ingredient in therapeutic change in many modalities. In addition, memory seems to play an important role but there is a lack of consensus on the role of understanding what happened in the past in bringing about therapeutic change.

The core idea of this paper is that therapeutic change in a variety of modalities, including behavioral therapy, cognitive-behavioral therapy, emotion-focused and psychodynamic psychotherapy, results from the updating of prior emotional memories through a process of reconsolidation that incorporates new emotional experiences. The authors present an integrative memory model with three interactive components - autobiographical (event) memories, semantic structures, and emotional responses - supported by emerging evidence from cognitive neuroscience on implicit and explicit emotion, implicit and explicit memory, emotion-memory interactions, memory reconsolidation, and the relationship between autobiographical and semantic memory. We propose that the essential ingredients of therapeutic change include: 1) reactivating old memories; 2) engaging in new emotional experiences that are incorporated into these reactivated memories via the process of reconsolidation; and 3) reinforcing the integrative memory structure by practicing a new way of behaving and experiencing the world in a variety of contexts. The implications of this new neurobiologically-grounded synthesis for research, clinical practice and teaching are discussed.

Making Our Brains Younger

I thought I would pass on this link to a brief (15 min) talk I gave to the Feb. 2, 2014, meeting of the Fort Lauderdale Prime Timers group. It discusses brain changes on aging and ways to reverse them. (I also have put a link to the talk in MindBlog's left column, and a photo taken by Kaz Takahashi at one of the few times I was smiling during the presentation.)

MindBlog's most read posts.

I'm doing a review of older MindBlog posts to see what categories collect themselves as potential talks or web-lectures of the sort you see in the left column.  I checked the statistics on what the most read posts have been since MindBlog started up in February of 2006, and thought I would pass that on to readers (click on the graphic to enlarge it). If you want to check out one of the posts, simply type a few words of the title into the search box to your left, and it will be retrieved.

The myth of cognitive decline with aging? Yes and No....

Offering something of an antidote to the drumbeat of articles measuring cognitive declines on again, Ramscar et al. (open source) suggest that changing performance patterns that are typically taken as evidence for (and measures of) cognitive decline arise out of basic principles of learning and emerge naturally in learning models as they acquire more knowledge, with patterns of performance reflect the information-processing costs that must inevitably be incurred as knowledge is acquired. Their arguments seem relevant to lexical tasks such as recalling words, but are not germane to declines in visual or auditory attention and processing speed (usually described as 'cognitive' declines) for which underlying brain structural and functional correlates have been observed. They also do not address the issue of noise, or competition from competing memories, as influencing lexical retrieval tasks. The second abstract below, work of Healey et al., notes this possibility. So, first the Ramscar et al. abstract:

As adults age, their performance on many psychometric tests changes systematically, a finding that is widely taken to reveal that cognitive information-processing capacities decline across adulthood. Contrary to this, we suggest that older adults'; changing performance reflects memory search demands, which escalate as experience grows. A series of simulations show how the performance patterns observed across adulthood emerge naturally in learning models as they acquire knowledge. The simulations correctly identify greater variation in the cognitive performance of older adults, and successfully predict that older adults will show greater sensitivity to fine-grained differences in the properties of test stimuli than younger adults. Our results indicate that older adults'; performance on cognitive tests reflects the predictable consequences of learning on information-processing, and not cognitive decline. We consider the implications of this for our scientific and cultural understanding of aging.

And now the Healey et al. abstract on noise or interference resolution by younger but not older adults:

Resolving interference from competing memories is a critical factor in efficient memory retrieval, and several accounts of cognitive aging suggest that difficulty resolving interference may underlie memory deficits such as those seen in the elderly. Although many researchers have suggested that the ability to suppress competitors is a key factor in resolving interference, the evidence supporting this claim has been the subject of debate. Here, we present a new paradigm and results demonstrating that for younger adults, a single retrieval attempt is sufficient to suppress competitors to below-baseline levels of accessibility even though the competitors are never explicitly presented. The extent to which individual younger adults suppressed competitors predicted their performance on a memory span task. In a second experiment, older adults showed no evidence of suppression, which supports the theory that older adults’ memory deficits are related to impaired suppression.

ADDED NOTE:

After I composed the above post Benedict Carey's mention of the Ramscar et al. article appeared in the NYTimes and became a 'most emailed article' for several days. He makes the same points that I do as a counter to over-interpreting Ramscar et al.'s data.

Most published scientific results are false.

I would highly recommend reading this article by George Johnson, which points in particular to the work of John P. A. Ioannidis, a kind of meta-scientist who researches research, who wrote a 2005 paper pointedly titled “Why Most Published Research Findings Are False.” Here is one clip from the Johnson article:

If one of five competing labs is alone in finding an effect, that result is the one likely to be published. But there is a four in five chance that it is wrong. Papers reporting negative conclusions are more easily ignored...Putting all of this together, Dr. Ioannidis devised a mathematical model supporting the conclusion that most published findings are probably incorrect....the same year he published another blockbuster, examining more than a decade’s worth of highly regarded papers — the effect of a daily aspirin on cardiac disease, for example, or the risks of hormone replacement therapy for older women. He found that a large proportion of the conclusions were undermined or contradicted by later studies.

His work was just the beginning. Concern about the problem has reached the point that the journal Nature has assembled an archive, filled with reports and analyses, called Challenges in Irreproducible Research.. Among them is a paper in which C. Glenn Begley, who is chief scientific officer at TetraLogic Pharmaceuticals, described an experience he had while at Amgen, another drug company. He and his colleagues could not replicate 47 of 53 landmark papers about cancer. Some of the results could not be reproduced even with the help of the original scientists working in their own labs....Given what is at stake, it seems like a moral failing that the titles of the papers were not revealed. That was forbidden, we’re told, by confidentiality agreements imposed by the labs.

Mindfulness has so totally gone mainstream…..

Mindfulness at Davos

Mindfulness - the Time Magazine cover story

Enriched environments enhance adult brain plasticity.

I learned much of my neuroscience at tea time in Hubel and Wiesel's laboratory at Harvard Medical School during my post-doc days in the 1960's, as we discussed their discovery of critical periods during the development of ocular dominance columns in the visual cortex, and the apparent immutability of the adult pathways, once formed. Everything now has changed. We know our brains maintain their ability to make new nerve cells and connections throughout life. Greifzu et. al. add a new chapter to the plasticity story in their recent work showing how important enriched environments are in maintaining a younger brain that has not been locked into place by the increased inhibitory interactions characteristic of adult brains. Specifically, they show that ocular dominance columns can remain plastic in adult mice in enriched, but not ordinary cage, environments, and recover from stroke-induced damage or monocular deprivation.

Experimental animals are usually raised in small, so-called standard cages, depriving them of numerous natural stimuli. We show that raising mice in an enriched environment, allowing enhanced physical, social, and cognitive stimulation, preserved a juvenile brain into adulthood. Enrichment also rejuvenated the visual cortex after extended periods of standard cage rearing and protected adult mice from stroke-induced impairments of cortical plasticity. Because the local inhibitory tone in the visual cortex of adult enriched mice was not only significantly reduced compared with nonenriched animals but at juvenile levels, the plasticity-promoting effect of enrichment is most likely mediated by preserving low juvenile levels of inhibition into adulthood and thereby, extending sensitive phases of enhanced neuronal plasticity into an older age.

How inactivity changes the brain

Here is yet another sobering note for couch potatoes. Lack of exercise (in rats) causes undesirable remodeling of the brain. Gretchen Reynolds points to work by Mischel et al. (open source) showing that inactive versus active rats show changes in the region of the rostral ventrolateral medulla that regulates the sympathetic nervous system, increasing connectivity and reactivity, potentially overstimulating the sympathetic nervous system to constrict blood vessels, increase blood pressure, and thus enhance the possibility of cardiovascular disease. Here is the Mischel et al. abstract and a summary figure:

Increased activity of the sympathetic nervous system is thought to play a role in the development and progression of cardiovascular disease. Recent work has shown that physical inactivity versus activity alters neuronal structure in brain regions associated with cardiovascular regulation. Our physiological studies suggest that neurons in the rostral ventrolateral medulla (RVLM) are more responsive to excitation in sedentary versus physically active animals. We hypothesized that enhanced functional responses in the RVLM may be due, in part, to changes in the structure of RVLM neurons that control sympathetic activity. We used retrograde tracing and immunohistochemistry for tyrosine hydroxylase (TH) to identify bulbospinal catecholaminergic (C1) neurons in sedentary and active rats after chronic voluntary wheel-running exercise. We then digitally reconstructed their cell bodies and dendrites at different rostrocaudal levels. The dendritic arbors of spinally projecting TH neurons from sedentary rats were more branched than those of physically active rats (P < 0.05). In sedentary rats, dendritic branching was greater in more rostral versus more caudal bulbospinal C1 neurons, whereas, in physically active rats, dendritic branching was consistent throughout the RVLM. In contrast, cell body size and the number of primary dendrites did not differ between active and inactive animals. We suggest that these structural changes provide an anatomical underpinning for the functional differences observed in our in vivo studies. These inactivity-related structural and functional changes may enhance the overall sensitivity of RVLM neurons to excitatory stimuli and contribute to an increased risk of cardiovascular disease in sedentary individuals.

Physical inactivity versus activity is associated with functional changes in control of blood pressure by neurons in the rostral ventrolateral medulla (RVLM). The present study shows that putative cardiovascular RVLM neurons have more complex dendrites in inactive versus active rats. This anatomical difference may underpin the functional differences previously reported.

The liberal illusion of uniqueness

Bill Clinton is reported to have complained that getting Democrats to agree on a course of action was like herding cats, while the Republicans didn’t seem to have this problem. Stern et al. do a fascinating nugget of work that shows that conservatives and moderates overestimate the degree to which others conservative and moderates are like them, while those on the left end of the spectrum assume they are more unique among party peers than they actually are. (Recall the inability of the Occupy Wall Street movement in 2011 to achieve consensus on vital issues.) The authors used well-validated methodology for examining truly false consensus and truly false uniqueness effects by developing a procedure in which participants were asked to indicate their beliefs and their preferences for a series of items and then estimate the beliefs and preferences of political in-group members. To test for truly false uniqueness and truly false consensus effects, They compared the extent to which participants perceived that political in-group members shared their beliefs and preferences with the extent to which political in-group members actually shared participants’ beliefs and preferences. From their methods section:

We conducted two studies in which participants reported their beliefs and preferences and estimated the beliefs and preferences of political in-group members who were either fellow participants in the study (Study 1) or members of the general American population (Study 2). This procedure allowed us to examine whether similar patterns of effects would emerge even when participants thought about political in-group members in different contexts. In Study 2, we replicated and extended Study 1 by examining whether the desire to feel unique explains in part ideological differences in estimating similarity to political in-group members. Finally, previous research has shown that individuals perceive more similarity between their own beliefs and those of other individuals (i.e., perceive greater consensus) when the beliefs are socially desirable or personally important. To rule out the possibility that these factors explain ideological differences in perceiving similarity to political in-group members, we measured the perceived social desirability of the items to which participants responded in both studies. In addition, in Study 2, we measured the personal importance of the items to rule out the possibility that this factor would explain ideological differences in perceiving similarity.

Here is their brief abstract.

In two studies, we demonstrated that liberals underestimate their similarity to other liberals (i.e., display truly false uniqueness), whereas moderates and conservatives overestimate their similarity to other moderates and conservatives (i.e., display truly false consensus; Studies 1 and 2). We further demonstrated that a fundamental difference between liberals and conservatives in the motivation to feel unique explains this ideological distinction in the accuracy of estimating similarity (Study 2). Implications of the accuracy of consensus estimates for mobilizing liberal and conservative political movements are discussed.

The Kerfuffle over whether men and women's brains are different.

Nothing kicks up a firestorm in the Neuroscience blogosphere like talk of sex differences in brain architecture. Within days of PNAS's early December 2013 publication of what may be a landmark paper on the differing 'connectomes' (nerve fiber tracts connecting different brain areas) of 428 male and 521 female 8-22 year old humans, a storm of criticism of the work was bouncing around the internet, along with accusations of 'neurosexism'. (see, for example, here, here, here, and here.)

The critics make many points - 1. Men have bigger brains on average than women, possibly conflating results; 2. Maybe men and women move their heads differently while in the MRI machine; 3. The structural differences don't necessarily correlate with behavioral differences, and there are varying results on whether the structural results correlate with cognitive function tests. It is unfortunate that the authors of the study were spouting gender stereotypes...but...it seems to me that the objections are mainly nit-picking, the data are rather compelling on fundamental differences in sexual connectivity that arise from genetic/environmental/cultural factors during brain development. (There is no such thing as 'hard wiring'.):

The results establish that male brains are optimized for intrahemispheric and female brains for interhemispheric communication. The developmental trajectories of males and females separate at a young age, demonstrating wide differences during adolescence and adulthood...The brains of men exhibit a far smaller degree of interconnectedness, both within and across the hemispheres, than do those of women.

I decided to wait for the dust to settle a bit, and let the final publication appear, and sure enough in the same issue there is an essay commentary by Larry Cahill that argues essentially that the politically correct view in brain research has been to assume no significant difference between male and female brain, and to assume results obtained (mainly for male brains) apply also to female brains.  Mouse studies in particular have shown that this is not the case.

...we now know that sex influences—small to medium to large—are extremely widespread on brain function. The validity of the assumption that the sex of subjects cannot powerfully alter, negate, and even reverse findings (hence, conclusions) has been crushed under the weight of evidence proving that it can and regularly does and at every level of investigation down to genes, single neurons, and even ion channels...For neuroscientists cognizant of this striking development, the main challenge now is to better understand the dizzying plethora of sex influences being uncovered. Males and females appear to be two complex mosaics, similar in some respects, mildly to highly different in others

Here is Cahill's summary comment:

A comedian discussing men and women once described the male brain as a bunch of boxes that don’t touch one another and the female brain as a complex ball of interconnected wires. Amusing as the bit was, the analogies may be more apt than he could have known. The findings of Ingahalikar et al. do indeed point to a greater degree of modular function in the physical architecture of the male brain and of interconnectedness in physical architecture of the female brain. Given the size of the study, the consistency of the conclusions across various analytic approaches, and the seeming concordance of key findings with well-established literature addressing brain function, one cannot fairly accuse Ingalhalikar et al. of hyperbole when they claim that their findings “reveal fundamental sex differences in the architecture of the human brain.” Theirs is a landmark paper that should accelerate acceptance of the notion that, for those who want to understand how brains function, sex matters.

And here, finally, is the Ingalhalikar et al. abstract:

Sex differences in human behavior show adaptive complementarity: Males have better motor and spatial abilities, whereas females have superior memory and social cognition skills. Studies also show sex differences in human brains but do not explain this complementarity. In this work, we modeled the structural connectome using diffusion tensor imaging in a sample of 949 youths (aged 8–22 y, 428 males and 521 females) and discovered unique sex differences in brain connectivity during the course of development. Connection-wise statistical analysis, as well as analysis of regional and global network measures, presented a comprehensive description of network characteristics. In all supratentorial regions, males had greater within-hemispheric connectivity, as well as enhanced modularity and transitivity, whereas between-hemispheric connectivity and cross-module participation predominated in females. However, this effect was reversed in the cerebellar connections. Analysis of these changes developmentally demonstrated differences in trajectory between males and females mainly in adolescence and in adulthood. Overall, the results suggest that male brains are structured to facilitate connectivity between perception and coordinated action, whereas female brains are designed to facilitate communication between analytical and intuitive processing modes.

Bodily maps of emotions.

Nummenmaa and collaborators, from several universities in Finland, propose that our emotions are represented in our somatosensory system as culturally universal categorical somatotopic maps.

Emotions are often felt in the body, and somatosensory feedback has been proposed to trigger conscious emotional experiences. Here we reveal maps of bodily sensations associated with different emotions using a unique topographical self-report method. In five experiments, participants (n = 701) were shown two silhouettes of bodies alongside emotional words, stories, movies, or facial expressions. They were asked to color the bodily regions whose activity they felt increasing or decreasing while viewing each stimulus. Different emotions were consistently associated with statistically separable bodily sensation maps across experiments. These maps were concordant across West European and East Asian samples. Statistical classifiers distinguished emotion-specific activation maps accurately, confirming independence of topographies across emotions. We propose that emotions are represented in the somatosensory system as culturally universal categorical somatotopic maps. Perception of these emotion-triggered bodily changes may play a key role in generating consciously felt emotions.

Figure - Bodily topography of basic (Upper) and nonbasic (Lower) emotions associated with words. The body maps show regions whose activation increased (warm colors) or decreased (cool colors) when feeling each emotion.

The morning morality effect.

Here is an interesting tidbit from Kouchaki1 and Smith:

Are people more moral in the morning than in the afternoon? We propose that the normal, unremarkable experiences associated with everyday living can deplete one’s capacity to resist moral temptations. In a series of four experiments, both undergraduate students and a sample of U.S. adults engaged in less unethical behavior (e.g., less lying and cheating) on tasks performed in the morning than on the same tasks performed in the afternoon. This morning morality effect was mediated by decreases in moral awareness and self-control in the afternoon. Furthermore, the effect of time of day on unethical behavior was found to be stronger for people with a lower propensity to morally disengage. These findings highlight a simple yet pervasive factor (i.e., the time of day) that has important implications for moral behavior.

The milliseconds of a choice - Watching your mind when it matters.

This is actually a post about mindfulness, in reaction to Dan Hurley's article describing how contemporary applications of the ancient tradition of mindfulness meditation are being engaged in many more contexts than the initial emphasis on chilling out in the 1970s, and being employed for very practical purses such as mental resilience in a war zone. It seems like to me that we are approaching a well defined technology of brain control whose brain basis is understood in some detail. I've done numerous posts on behavioral and brain correlates of mindfulness meditation (enter 'meditation' or 'mindfulness' in MindBlog's search box in the left column). For example, only four weeks of a mindfulness meditation regime emphasizing relaxation of different body parts correlates with increases in white matter (nerve tract) efficiency. Improvements in cognitive performance, working memory, etc. have been claimed. A special issue of The journal Social Cognitive and Affective Neuroscience discusses issue in the research.

Full time mindfulness might be a bad idea, suppressing the mind wandering that facilitates bursts of creative insight. (During my vision research career, my most original ideas popped up when I was spacing out, once when I was riding a bike along a lakeshore path.) Many physicists and writers reports their best ideas happen when they are disengaged. It also appears that mindfulness may inhibit implicit learning in which habits and skill are acquired without conscious awareness.

Obviously knowing whether we are in an attentional or mind wandering (default, narrative) modes is useful (see here, and here), and this is where the title of this posts comes in. To note and distinguish our mind state is most effectively accomplished with a particular style of alertness or awareness that is functioning very soon (less than 200 milliseconds) after a new thought or sensory perception appears to us. This is a moment of fragility that offers a narrow time window of choice over whether our new brain activity will be either enhanced or diminished in favor of a more desired activity. This is precisely what is happening in mindfulness meditation that instructs a central focus of some sort (breathing, body relaxation, or whatever) to which one returns as soon as one notes that any other thoughts or distractions have popped into awareness. The ability to rapidly notice and attend to thoughts and emotions of these short time scales is enhanced by brain training regimes of the sort offered by BrainHq of positscience.com and others. I have found the exercises on this site, originated by Michael Merznich, to be the most useful.  It offers summaries of changes in brain speed, attention, memory, intelligence, navigation, etc. that result from performing the exercises - changes that can persist for years.

A book title that has been popping into my head for at least the last 15 years is "The 200 Millisecond Manager." (a riff on the title the popular book of the early 1980's by Blanchard and Johnson, "The One Minute Manager.") The gist of the argument would be that given in the "Guide" section of some 2005 writing, and actually in Chapter 12 of my book, Figure 12-7.

It might make the strident assertion that the most important thing that matters in regulating our thoughts, feelings, and actions is their first 100-200 msec in the brain, which is when the levers and pulleys are actually doing their thing. It would be a nuts and bolts approach to altering - or at least inhibiting - self limiting behaviors. It would suggest that a central trick is to avoid taking on on the ‘enormity of it all,’ and instead use a variety of techniques to get our awareness down to the normally invisible 100-200 msec time interval in which our actions are being programmed. Here we are talking mechanics during the time period is when all the limbic and other routines that result from life script, self image, temperament, etc., actually can start-up. The suggestion is that you can short circuit some of this process if you bring awareness to the level of observing the moments during which a reaction or behavior is becoming resident, and can sometimes say “I don’t think so, I think I'll do something else instead.”

"The 200 msec Manager" has gone through the ‘this could be a book’ cycle several times, the actual execution  bogging down as I actually got into description of the underlying science and techniques for expanding awareness. Also, I note the enormous number of books out there on meditation, relaxation, etc. that are all really addressing the same core processes in different ways.