Watching our auditory brain, like a radio, switch hearing frequency channels.

From Da Costa et al.:

Cocktail parties, busy streets, and other noisy environments pose a difficult challenge to the auditory system: how to focus attention on selected sounds while ignoring others? Neurons of primary auditory cortex, many of which are sharply tuned to sound frequency, could help solve this problem by filtering selected sound information based on frequency-content. To investigate whether this occurs, we used high-resolution fMRI at 7 tesla to map the fine-scale frequency-tuning (1.5 mm isotropic resolution) of primary auditory areas A1 and R in six human participants. Then, in a selective attention experiment, participants heard low (250 Hz)- and high (4000 Hz)-frequency streams of tones presented at the same time (dual-stream) and were instructed to focus attention onto one stream versus the other, switching back and forth every 30 s. Attention to low-frequency tones enhanced neural responses within low-frequency-tuned voxels relative to high, and when attention switched the pattern quickly reversed. Thus, like a radio, human primary auditory cortex is able to tune into attended frequency channels and can switch channels on demand.

Amygdala damage can make us more generous

From van Honk et al.:

Contemporary economic models hold that instrumental and impulsive behaviors underlie human social decision making. The amygdala is assumed to be involved in social-economic behavior, but its role in human behavior is poorly understood. Rodent research suggests that the basolateral amygdala (BLA) subserves instrumental behaviors and regulates the central-medial amygdala, which subserves impulsive behaviors. The human amygdala, however, typically is investigated as a single unit. If these rodent data could be translated to humans, selective dysfunction of the human BLA might constrain instrumental social-economic decisions and result in more impulsive social-economic choice behavior. Here we show that humans with selective BLA damage and a functional central-medial amygdala invest nearly 100% more money in unfamiliar others in a trust game than do healthy controls. We furthermore show that this generosity is not caused by risk-taking deviations in nonsocial contexts. Moreover, these BLA-damaged subjects do not expect higher returns or perceive people as more trustworthy, implying that their generous investments are not instrumental in nature. These findings suggest that the human BLA is essential for instrumental behaviors in social-economic interactions.

Here is the anatomical location of the human lesions:

MR images (coronal view) of the three subjects with Urbach–Wiethe disease (UWD), with their year of birth and red crosshairs indicating the calcified brain damage...the lesions of the three patients are located in the BLA...the functional method shows activation during emotion matching in the superficial amygdala (SFA) and CMA, but not in the BLA.

How our viscera influence our brain and behavior

I want to pass on this fascinating and useful open source review by Critchley and Harrison in the journal Neuron. Having just had the flu, I found their presentation of visceral regulation of sickness behaviors very relevant! The article is worthwhile especially for the summary figures showing functional and anatomical pathways. (I resist the urge to paste them into this post, you can look at them by clicking on the link above. Here is their abstract:

Mental processes and their neural substrates are intimately linked to the homeostatic control of internal bodily state. There are a set of distinct interoceptive pathways that directly and indirectly influence brain functions. The anatomical organization of these pathways and the psychological/behavioral expressions of their influence appear along discrete, evolutionarily conserved dimensions that are tractable to a mechanistic understanding. Here, we review the role of these pathways as sources of biases to perception, cognition, emotion, and behavior and arguably the dynamic basis to the concept of self.

And, two clips from the text:

The internal state of the body motivates our desire to walk in the shade on a warm summer’s day and inhibits the desire to eat or socialize when feeling off-color. Communication from the viscera to brain is continuous and pervasive, yet we rarely give it a second thought. Visceral fluctuations and reactions accessible to introspective appraisal represent only the visible tip of the iceberg.

A comprehensive understanding of the integration of internal bodily signals in health is ultimately required for effective management of physical and psychological symptoms in illness. Such a goal can only be achieved through coordinated experimental approaches and perhaps a move away from treating physiological changes as irrelevant confounds in neuropsychological experiments. Together, these observations make “us realize more deeply than ever how much of our mental life is knit up in our corporeal frame” (James, 1890).

How ambient light might influence our mood.

The visual pigment melanopsin in the intrinsically photosensitive retinal ganglion cells (ipRGCs) of our inner retinas (two cells layers away from our rods and cones) detect ambient light and send this information to brain areas that regulate circadian rhythms and mood. LaGates et al. have now found that inappropriately timed light exposure that does not alter normal sleep architecture and circadian rhythmicity of body temperature and general activity still can cause impaired learning and depression-like behaviors in mice. In mice genetically altered to remove ipRGC cells, the depressive-like behaviors and learning deficits are not observed. If similar mechanisms operate in us humans, this suggests a potential mechanism by which abnormal ambient light schedules — caused by shift work or simply switching on an artificial light — might influence mood and learning. Here is their abstract:

The daily solar cycle allows organisms to synchronize their circadian rhythms and sleep–wake cycles to the correct temporal niche. Changes in day-length, shift-work, and transmeridian travel lead to mood alterations and cognitive function deficits. Sleep deprivation and circadian disruption underlie mood and cognitive disorders associated with irregular light schedules. Whether irregular light schedules directly affect mood and cognitive functions in the context of normal sleep and circadian rhythms remains unclear. Here we show, using an aberrant light cycle that neither changes the amount and architecture of sleep nor causes changes in the circadian timing system, that light directly regulates mood-related behaviours and cognitive functions in mice. Animals exposed to the aberrant light cycle maintain daily corticosterone rhythms, but the overall levels of corticosterone are increased. Despite normal circadian and sleep structures, these animals show increased depression-like behaviours and impaired hippocampal long-term potentiation and learning. Administration of the antidepressant drugs fluoxetine or desipramine restores learning in mice exposed to the aberrant light cycle, suggesting that the mood deficit precedes the learning impairments. To determine the retinal circuits underlying this impairment of mood and learning, we examined the behavioural consequences of this light cycle in animals that lack intrinsically photosensitive retinal ganglion cells. In these animals, the aberrant light cycle does not impair mood and learning, despite the presence of the conventional retinal ganglion cells and the ability of these animals to detect light for image formation. These findings demonstrate the ability of light to influence cognitive and mood functions directly through intrinsically photosensitive retinal ganglion cells.

The lament of the historian…

My colleague William Cronon at the University of Wisconsin was President of the American Historical Association for 2012,  and I want to pass on a clip from the AHA Presidential Address he delivered in Jan. 2013.  Among his concerns about the future of historical studies as a discipline is the digital revolution and internet that are transforming literally everything about the way historians work and how people read:

One of my deepest fears about this brave new digital world has to do with reading itself...It seems to me that the book-length monograph on which our discipline has long relied is very much at risk as texts migrate from paper to screens. It is not just that libraries are reducing purchases, that university presses are facing cutbacks, or that declining print runs and rising per-unit costs are pricing many specialized monographs beyond the reach of ordinary buyers. My deeper fear comes from watching my own students, many of whom no longer read books for pleasure. If they have any prior experience doing research, almost all of it is online. If a piece of information cannot be Googled, it effectively does not exist for them. More than a few of my students have never actually been inside the stacks of a library. To the extent that good writing is predicated on frequent skilled reading, the ability of such students to recognize and construct grammatical sentences and paragraphs—let alone graceful or elegant ones—is plummeting.

In a manically multitasking world where even e-mail takes too long to read, where texts and tweets and Facebook postings have become dominant forms of communication, reading itself is more at risk than many of us realize. Or, to be more precise, long-form reading is at risk: the ability to concentrate and sustain one's attention on arguments and narratives for many hours and many thousands of words. I have come to think of this as the Anna Karenina problem: will students twenty years from now be able to read novels like Tolstoy's that are among the greatest works of world literature but that require dozens of hours to be meaningfully experienced? And if a novel as potent as Anna lies beyond reach, what does that imply for complex historical monographs that are in many ways even more challenging in the demands they make on readers?

What is the future of history?...there is one answer that is arguably the most basic of all, and that is, simply: storytelling. We need to remember the roots of our discipline and be sure to keep telling stories that matter as much to our students and to the public as they do to us. Although the shape and form of our stories will surely change to meet the expectations of this digital age, the human need for storytelling is not likely ever to go away. It is far too basic to the way people make sense of their lives—and among the most important stories they tell are those that seek to understand the past. Hang on to this truth, and there is no reason to fear that history will be any less important to the human future than it has been to the human past.

In an uncertain world, fairness finishes first.

I usually get hopelessly lost in accounts of variations of the ultimatum game used to model human behavior and its evolutionary rationale or origins. This experiment by Rand et al. seems relatively clear and crisp:

Classical economic models assume that people are fully rational and selfish, while experiments often point to different conclusions. A canonical example is the Ultimatum Game: one player proposes a division of a sum of money between herself and a second player, who either accepts or rejects. Based on rational self-interest, responders should accept any nonzero offer and proposers should offer the smallest possible amount. Traditional, deterministic models of evolutionary game theory agree: in the one-shot anonymous Ultimatum Game, natural selection favors low offers and demands. Experiments instead show a preference for fairness: often responders reject low offers and proposers make higher offers than needed to avoid rejection. Here we show that using stochastic evolutionary game theory, where agents make mistakes when judging the payoffs and strategies of others, natural selection favors fairness. Across a range of parameters, the average strategy matches the observed behavior: proposers offer between 30% and 50%, and responders demand between 25% and 40%. Rejecting low offers increases relative payoff in pairwise competition between two strategies and is favored when selection is sufficiently weak. Offering more than you demand increases payoff when many strategies are present simultaneously and is favored when mutation is sufficiently high. We also perform a behavioral experiment and find empirical support for these theoretical findings: uncertainty about the success of others is associated with higher demands and offers; and inconsistency in the behavior of others is associated with higher offers but not predictive of demands. In an uncertain world, fairness finishes first.

Big brains decrease fertility.

More intelligent mammals, such as humans, whales, and dolphins, have decreased fertility. One ideas has been that the energetic cost of increased brain power has been meet by decreasing the size of the gut and decreasing reproductive function. Kotrschal et al. have tested this idea by selecting for brain size in guppies and obtaining populations of fish whose brains were larger or smaller than normal and differed from one another by about 10%. The cost of the increased brain power was a decrease in the size of the gut and a decrease in reproductive function. Here is their abstract:

The large variation in brain size that exists in the animal kingdom has been suggested to have evolved through the balance between selective advantages of greater cognitive ability and the prohibitively high energy demands of a larger brain (the “expensive-tissue hypothesis”). Despite over a century of research on the evolution of brain size, empirical support for the trade-off between cognitive ability and energetic costs is based exclusively on correlative evidence, and the theory remains controversial. Here we provide experimental evidence for costs and benefits of increased brain size. We used artificial selection for large and small brain size relative to body size in a live-bearing fish, the guppy (Poecilia reticulata), and found that relative brain size evolved rapidly in response to divergent selection in both sexes. Large-brained females outperformed small-brained females in a numerical learning assay designed to test cognitive ability. Moreover, large-brained lines, especially males, developed smaller guts, as predicted by the expensive-tissue hypothesis, and produced fewer offspring. We propose that the evolution of brain size is mediated by a functional trade-off between increased cognitive ability and reproductive performance and discuss the implications of these findings for vertebrate brain evolution.

How mindfulness meditation works in the brain - a model

Kerr et al make some interesting speculations. Their article contains some useful summary graphics.

Using a common set of mindfulness exercises, mindfulness based stress reduction (MBSR) and mindfulness based cognitive therapy (MBCT) have been shown to reduce distress in chronic pain and decrease risk of depression relapse. These standardized mindfulness (ST-Mindfulness) practices predominantly require attending to breath and body sensations. Here, we offer a novel view of ST-Mindfulness's somatic focus as a form of training for optimizing attentional modulation of 7–14 Hz alpha rhythms that play a key role in filtering inputs to primary sensory neocortex and organizing the flow of sensory information in the brain. In support of the framework, we describe our previous finding that ST-Mindfulness enhanced attentional regulation of alpha in primary somatosensory cortex (SI). The framework allows us to make several predictions. In chronic pain, we predict somatic attention in ST-Mindfulness “de-biases” alpha in SI, freeing up pain-focused attentional resources. In depression relapse, we predict ST-Mindfulness's somatic attention competes with internally focused rumination, as internally focused cognitive processes (including working memory) rely on alpha filtering of sensory input. Our computational model predicts ST-Mindfulness enhances top-down modulation of alpha by facilitating precise alterations in timing and efficacy of SI thalamocortical inputs. We conclude by considering how the framework aligns with Buddhist teachings that mindfulness starts with “mindfulness of the body.” Translating this theory into neurophysiology, we hypothesize that with its somatic focus, mindfulness' top-down alpha rhythm modulation in SI enhances gain control which, in turn, sensitizes practitioners to better detect and regulate when the mind wanders from its somatic focus. This enhanced regulation of somatic mind-wandering may be an important early stage of mindfulness training that leads to enhanced cognitive regulation and metacognition.

Interdependent behavior facilitated by independent behavior?

Hamedani et al. , who end up suggesting that it may be necessary to invoke independent behaviors in order to successfully motivate interdependence, start their article with a Quote:

"Each time I look at that flag, I’m reminded that our destiny is stitched together like those 50 stars and those 13 stripes . . . And if we hold fast to that truth, in this moment of trial, there is no challenge too great." "—U.S. president Barack Obama, State of the Union address, January 24, 2012 "

They then outline the context for their study on factors that influence the kinds of interdependent behavior needed to face problems common to all people, such as the environmental crisis. They:

...compared European Americans, who have been exposed primarily to mainstream cultural contexts that promote and value independence, with East Asian Americans, who have been exposed both to these contexts and also to cultural contexts that promote and value interdependence. Asian Americans are considered bicultural because they are exposed not only to mainstream American contexts that foster independent behavior (e.g., in schools and workplaces), but also to East Asian contexts that foster interdependent behavior (e.g., in families and communities)...This European American/Asian American cultural contrast allowed us to examine whether independence necessarily functions as a barrier to interdependent awareness and action. Comparing two American groups who are similar in their exposure to independence but different in their exposure to interdependence enabled us to test the theory that interdependence may undermine motivation because of a lack of exposure to cultural contexts that promote and value it as a normatively “good” style of behavior.1 Specifically, we tested the hypothesis that invoking interdependent behavior, compared with invoking independent behavior, would undermine motivation for European Americans but not for bicultural Asian Americans.

Here is their abstract:

Today’s most pressing social challenges require people to recognize their shared fate and work together—to think and act interdependently. In the three studies reported here, we found that appeals for increased interdependence may undermine the very motivation they seek to inspire. We examined the hypothesis that invoking interdependent action undermines motivation for chronically independent European Americans but not for bicultural Asian Americans who are both chronically independent and chronically interdependent. Two studies demonstrated that priming interdependent rather than independent action undermined European Americans’ motivation to perform challenging mental and physical tasks. A third study showed that framing an appeal for environmental sustainability in terms of interdependent rather than independent action led to decreased motivation and resource allocation among European Americans. Motivation was not undermined for Asian Americans, which reveals how behavior is divergently shaped, in the land of the free, by foundational sociocultural schemas of independence and interdependence. This research has the novel implication that it may be necessary to invoke independent behaviors in order to successfully motivate interdependence.

Red Brain, Blue Brain

Darren Schreiber and collaborators add yet another article to what is a growing literature on the differing sensitivities to threat of liberals and conservatives. Their open access article shows brain imaging and behavioral correlates. It seems likely not only that having a particular brain would influence our political views, but also that having a particular political view would influence and change our brains. The causal arrow seems likely to run in both directions—which would make sense in light of what we know about the plasticity of the brain.

Liberals and conservatives exhibit different cognitive styles and converging lines of evidence suggest that biology influences differences in their political attitudes and beliefs. In particular, a recent study of young adults suggests that liberals and conservatives have significantly different brain structure, with liberals showing increased gray matter volume in the anterior cingulate cortex, and conservatives showing increased gray matter volume in the in the amygdala. Here, we explore differences in brain function in liberals and conservatives by matching publicly-available voter records to 82 subjects who performed a risk-taking task during functional imaging. Although the risk-taking behavior of Democrats (liberals) and Republicans (conservatives) did not differ, their brain activity did. Democrats showed significantly greater activity in the left insula, while Republicans showed significantly greater activity in the right amygdala. In fact, a two parameter model of partisanship based on amygdala and insula activations yields a better fitting model of partisanship than a well-established model based on parental socialization of party identification long thought to be one of the core findings of political science. These results suggest that liberals and conservatives engage different cognitive processes when they think about risk, and they support recent evidence that conservatives show greater sensitivity to threatening stimuli.

Chimps play fair in the ultimatum game.

These interesting observations by Proctor, de Waal et al. using a new experimental design that resolves conflicting data in studies by other authors suggest that our human sense of fairness has an early origin in primate behavior.

Is the sense of fairness uniquely human? Human reactions to reward division are often studied by means of the ultimatum game, in which both partners need to agree on a distribution for both to receive rewards. Humans typically offer generous portions of the reward to their partner, a tendency our close primate relatives have thus far failed to show in experiments. Here we tested chimpanzees (Pan troglodytes) and human children on a modified ultimatum game. One individual chose between two tokens that, with their partner’s cooperation, could be exchanged for rewards. One token offered equal rewards to both players, whereas the other token favored the chooser. Both apes and children responded like humans typically do. If their partner’s cooperation was required, they split the rewards equally. However, with passive partners—a situation akin to the so-called dictator game—they preferred the selfish option. Thus, humans and chimpanzees show similar preferences regarding reward division, suggesting a long evolutionary history to the human sense of fairness.

How we listen to music...

Adam Gopnik has a very nice essay in The New Yorker on the mysteries of sound and the quest for 3-D recording. I was struck by his description of how the way we listen to music has changed. (I sometimes think with nostalgia about growing up in a 1950's household where "Hi Fidelity" was taken very seriously, trying as closely as possible to re-create the experience in the concert hall. Good old analog vinyl records played on mechanically sophisticated turntables with fancy diamond needles tracking the grooves, state of the art amplifiers, and speakers.... And now I have the best quality wireless speaker one can get, but it still must depend entirely on the compressed audio computer file formats such as .mp3 or.aiff, that throw away the richness I used to know.) His comments on how the music listening of his teen-age kids has changed, they:

...have an entirely different way of listening. They ignore the glowing-tube amp and classy articulate speakers in our living room; they bounce instead to tinny earbuds, and often spend hours listening to Taylor Swift or Radiohead on the still more tinny speakers of their computers. Sound quality seems secondary to some other thing they take from music...they have a more limited conception of larger forms, of the... of the symphony's three or four parts, of the swell and structure of a cantata. It isn't a question of classical tastes against pop; it's a question of small forms heard in motion against large form heard with solemn intent. "Sgt. Pepper: baffles them as much as Beethoven's Ninth. They snatch at music as we snatched at movies, filling our heads with plural images.

Gopnik's article presents fascinating interviews with current music researchers, from engineers like Edgar Choueiri to brain scientists such as Zatorre and Levitin at McGill University in Montreal. (MindBlog has several posts on their work.)

Internal threats to our bodies trigger different fear system from external threats.

A large volume of work has documented the amygdala's role in fear, and now Feinstein et al. present a surprising finding that carbon dioxide inhalation evokes fear and panic in three patients with bilateral amygdala damage (who feel no fear from external threats). These results indicate that the amygdala is not required for fear triggered internally rather than by external threats.  Here is the abstract:

Decades of research have highlighted the amygdala's influential role in fear. We found that inhalation of 35% CO₂ evoked not only fear, but also panic attacks, in three rare patients with bilateral amygdala damage. These results indicate that the amygdala is not required for fear and panic, and make an important distinction between fear triggered by external threats from the environment versus fear triggered internally by CO₂.

Why do these 'fearless' patients feel fear when CO₂ levels in their blood are increased? The authors suggest:

...that all of these other stimuli were exteroceptive in nature, mainly processed through visual and auditory pathways that project to the amygdala. In contrast, CO₂ acts internally at acid-activated chemoreceptors and causes an array of physiological changes. Thus, CO₂ might engage interoceptive afferent sensory pathways that project to the brainstem, diencephalon and insular cortex. In addition, many brain areas outside the amygdala possess CO2 and pH-sensitive chemoreceptors, including acid-sensing ion channels. Thus, CO₂ may directly activate extra-amygdalar brain structures that underlie fear and panic, which may help to explain the apparent discrepancy between these findings and previous work in mice. In either case, our results indicate that, in humans, the internal threat signaled by CO₂ is detected and interpreted as fear and panic despite the absence of an intact amygdala.

Wisconsin Public Radio series on consciousness

I've been wanting to point to an engaging series of interviews on consciousness presented by Wisconsin Public Radio either for listening, or in transcript form.  A wide range of philosophers, scientists, and new age gurus are engaged, including Marvin Minsky, Roger Penrose, Daniel Dennett, Alva Noe, Susan Blackmore, David Chalmers, Christof Koch, Guilio Tononi,  Stanislav Grof, Michael Gazzaniga, Depak Chopra, V.S. Ramachandran, Oliver Sacks, and many others.  It's quite an amazing and extensive list.   

We can retroactively edit our conscious experience.

Have you ever had the experience of tuning out someone who was droning on in a conversation or lecture that was boring you, then when suddenly being challenged by "Are you listening, what did I just say?," being surprised that you could summon up some recall of what they said, even though you had been completely ignoring it? This would be an example of how our perceptions and our consciousness can be two different things. We experience time very differently from what it really is, subjective and objective time are not the same. Our consciousness is more than just a movie that's playing in your head that you see once the processing is done. For example, recent work from Sergent and collaborators suggests that we can go back in time for at least a half a second and reintegrate something into our experience that we had previously ignored. From a review by Tia Ghose:

Study participants were shown groups of lines appearing in a circle on either the right or the left side of the screen before they disappeared. Sometimes the lines were too faint to consciously notice, while other times they were very obvious. In some of the trials where the lines were very faint, the researchers drew participants' attention to the spot where the lines had been by briefly dimming the circle — creating more contrast between the circle and the background. That "cueing of attention" happened up to a half-second after the lines disappeared. Afterward, the team asked the students what they saw. When the team had drawn attention to the spot where the lines had been, people were more likely to report having seen them "quite well." In essence, the participants had experienced retro-perception, the bizarre experience in which their brains added the lines to their conscious memory after the lines had disappeared.

Here is the Sergent et al. abstract:

Is our perceptual experience of a stimulus entirely determined during the early buildup of the sensory representation, within 100 to 150 ms following stimulation? Or can later influences, such as sensory reactivation, still determine whether we become conscious of a stimulus? Late visual reactivation can be experimentally induced by postcueing attention after visual stimulus offset [5]. In a contrary approach from previous work on postcued attention and visual short-term memory, which used multiple item displays [6 and 7], we tested the influence of postcued attention on perception, using a single visual stimulus (Gabor patch) at threshold contrast. We showed that attracting attention to the stimulus location 100 to 400 ms after presentation still drastically improved the viewers’ objective capacity to detect its presence and to discriminate its orientation, along with drastic increase in subjective visibility. This retroperception effect demonstrates that postcued attention can retrospectively trigger the conscious perception of a stimulus that would otherwise have escaped consciousness. It was known that poststimulus events could either suppress consciousness, as in masking, or alter conscious content, as in the flash-lag illusion. Our results show that conscious perception can also be triggered by an external event several hundred ms after stimulus offset, underlining unsuspected temporal flexibility in conscious perception.

Deric Bownds' MindBlog - 7th Anniversary

I just realized that today, 7 years ago on Feb. 8, 2006, was my first posting on this blog, which I started after reading a New York Times article on the emerging blogging craze. Now, 3,024 posts later, I'm sort of incredulous that it has stayed around so long. It appears, from Feedburner monitoring that has been going on since June of 2006, that there are now about 2,500 subscribers to MindBlog's feed, there are an average of ~380 significant engagements of readers with the blog every day, and there have been a total of about 1.5 million views. The paste in below shows postings that have received with most views. Just keeping up with MindBlog maintenance is a bit of effort. Every week 3-4 emails come in requesting quest postings or cross links, or offering revenue opportunities. My cut and paste boilerplate response: "I find that I'm receiving a large number of similar requests,  and have a policy of entering on my site only content that I initiate.   I have no commercial links on the site and am uninterested in revenue." 

I must apologize if your comments do not appear immediately, but I've been forced to start reviewing them again to weed out those that are are platitudes with links to commercial sites - they  now outnumber legitimate comments. 

About this time every year I have an identity crisis over whether I should continue the blog and/or develop a next lecture/essay topic, and/or write a book, spend more time with my piano...or just lie in the sun a bit more...  I usually just keep plugging along doing what I have been doing... Soon to be 71 years old, I find the motivation to change my habits declining.  And,  I am gratified by the occasional "thank you for the blog"  email that I get. 

The cocktail party effect is enhanced by vision.

Golumbic et al. show that watching someone we are trying to hear and understand in a crowded noisy setting sharpens up the auditory processing in our brains that suppresses unwanted sounds from our surround:

Our ability to selectively attend to one auditory signal amid competing input streams, epitomized by the “Cocktail Party” problem, continues to stimulate research from various approaches. How this demanding perceptual feat is achieved from a neural systems perspective remains unclear and controversial. It is well established that neural responses to attended stimuli are enhanced compared with responses to ignored ones, but responses to ignored stimuli are nonetheless highly significant, leading to interference in performance. We investigated whether congruent visual input of an attended speaker enhances cortical selectivity in auditory cortex, leading to diminished representation of ignored stimuli. We recorded magnetoencephalographic signals from human participants as they attended to segments of natural continuous speech. Using two complementary methods of quantifying the neural response to speech, we found that viewing a speaker's face enhances the capacity of auditory cortex to track the temporal speech envelope of that speaker. This mechanism was most effective in a Cocktail Party setting, promoting preferential tracking of the attended speaker, whereas without visual input no significant attentional modulation was observed.

These neurophysiological results underscore the importance of visual input in resolving perceptual ambiguity in a noisy environment. Since visual cues in speech precede the associated auditory signals, they likely serve a predictive role in facilitating auditory processing of speech, perhaps by directing attentional resources to appropriate points in time when to-be-attended acoustic input is expected to arrive.

Aging, sleep, and memory.

Events during a day that we think important to remember are held in short term memory storage by an active hippocampus. Then, during deep, non-REM, slow brain wave sleep, enhanced connectivity between the hippocampus and frontal cortex cortex allow transfer of the information to long term storage in frontal and temporal lobes. It is also know that the duration of this deep sleep diminishes as our frontal lobes diminish in size (atrophy) with aging. Mandor et al., in worked pointed to in an article by Benedict Carey, have done an interesting study suggesting that the interaction of these factors represents a neuropatholgical pathway associated with cognitive decline in later life. Here is their abstract:

Aging has independently been associated with regional brain atrophy, reduced slow wave activity (SWA) during non–rapid eye movement (NREM) sleep and impaired long-term retention of episodic memories. However, whether the interaction of these factors represents a neuropatholgical pathway associated with cognitive decline in later life remains unknown. We found that age-related medial prefrontal cortex (mPFC) gray-matter atrophy was associated with reduced NREM SWA in older adults, the extent to which statistically mediated the impairment of overnight sleep–dependent memory retention. Moreover, this memory impairment was further associated with persistent hippocampal activation and reduced task-related hippocampal-prefrontal cortex functional connectivity, potentially representing impoverished hippocampal-neocortical memory transformation. Together, these data support a model in which age-related mPFC atrophy diminishes SWA, the functional consequence of which is impaired long-term memory. Such findings suggest that sleep disruption in the elderly, mediated by structural brain changes, represents a contributing factor to age-related cognitive decline in later life.

Racial essentialism correlates with less domain-general creativity.

Interesting observations from a group at Tel Aviv University:

Individuals who believe that racial groups have fixed underlying essences use stereotypes more than do individuals who believe that racial categories are arbitrary and malleable social-political constructions. Would this essentialist mind-set also lead to less creativity? We suggest that the functional utility derived from essentialism induces a habitual closed-mindedness that transcends the social domain and hampers creativity. Across studies, using both individual difference measures (in a pilot test) and experimental manipulations, we found that an essentialist mind-set is indeed hazardous for creativity, with the relationship mediated by motivated closed-mindedness. These results held across samples of majority cultural-group members (Caucasian Americans, Israelis) and minority-group members (Asian Americans), as well as across different measures of creativity (flexibility, association, insight). Our findings have important implications for understanding the connection between racial intolerance and creativity.

Some details: Participants in the study were primed by reading an article that vividly described fictitious scientific research supporting either racial essentialist or nonessentialist beliefs, respectively. (Work by others had established the effectiveness of these articles in activating racial essentialism or nonessentialism mind-sets). A control group read neither article. Then, in an ostensibly unrelated research project, they measured creativity in the three conditions using the Remote Associates Test (RAT). This task, which assesses participants’ ability to form a new combination that links mentally distant associative elements, requires identifying a single target word that is strongly associated with three distinct stimulus words (e.g., given the words “manners,” “round,” and “tennis,” the correct answer would be “table”). Their experiment suggesting closed-mindedness as the mediator of the essentialism-creativity link used the same priming procedure and assayed insight creativity using the Duncker candle problem, in which participants have to figure out how — using only a candle, a pack of matches, and a box containing tacks — they can attach the candle to a wall so that the candle burns properly without dripping wax on the table or floor. (The correct solution requires the ability to relax preexisting assumptions about functions of the items and use the box of tacks as a candleholder.)

"Chasing Ice" - watching a glacier calving

 I have to pass on this amazing video shared by Wisconsin colleague John Young, showing one of the breakdowns of a glacier that has retreated as much in the past 10 years as in the previous 100 years:

Early musical training - sensitive period in brain white matter plasticity

MindBlog has noted a number of studies that document beneficial effects of early music training on adult brain function. Now Steele and collaborators make observations that may partially explain why musicians such as Yo-Yo Ma, Oscar Peterson, and Pablo Casals, who all began training in early childhood before the age of 7 years, are so highly skilled. The authors examine the bundle of nerve fibers, the corpus callosum, that links our two cerebral hemispheres. Playing a musical instrument requires the coordinated action of the two hands and interhemispheric interactions mediated by the corpus callosum have been shown to play a prominent role in bimanual coordination. They measure the connectivity of this nerve fiber bundle using MRI. Edited from their introduction:

...there may be a sensitive period when early musical training has greater effects on the brain and behavior than training later in life...A sensitive period is defined as a developmental window where experience has long-lasting effects on the brain and behavior ...studies in animals show that exposure or training during specific periods in development can produce enhanced structural and functional plasticity in visual, auditory, and somatosensory regions of the brain...Evidence for sensitive periods in humans comes from studies of second language learning showing that early exposure results in greater proficiency, studies of deaf children showing that receiving cochlear implants earlier results in better language development, and studies of blind persons showing greater neuronal reorganization following early blindness.

Musicians are an excellent model for investigating possible sensitive period effects on brain and behavior, as training often begins early and is quantifiable...Evidence for a possible sensitive period for musical training came from a study showing that the anterior corpus callosum (CC) was larger in musicians than non-musicians, and that the difference was greater for those who began training before the age of 7 years...However, none of these studies controlled for the fact that musicians who begin earlier typically have more training than those who begin later.

Here is their abstract:

Training during a sensitive period in development may have greater effects on brain structure and behavior than training later in life. Musicians are an excellent model for investigating sensitive periods because training starts early and can be quantified. Previous studies suggested that early training might be related to greater amounts of white matter in the corpus callosum, but did not control for length of training or identify behavioral correlates of structural change. The current study compared white-matter organization using diffusion tensor imaging in early- and late-trained musicians matched for years of training and experience. We found that early-trained musicians had greater connectivity in the posterior midbody/isthmus of the corpus callosum and that fractional anisotropy in this region was related to age of onset of training and sensorimotor synchronization performance. We propose that training before the age of 7 years results in changes in white-matter connectivity that may serve as a scaffold upon which ongoing experience can build.

The promise and perils of oxytocin.

Greg Miller summarizes some consequences of recent work showing that oxytocin promotes trust and cooperation, and makes people more attuned to social cues.  It has some not so sweet aspects also.  He mentions a number of the studies I've cited in previous mindblog posts (just enter oxytocin in the search box in the left column to display them):

Now psychiatrists have caught oxytocin fever...Many psychiatric conditions have social symptoms, such as the characteristic lack of empathy in autism, the attachment anxiety of borderline personality disorder, and the paranoia of schizophrenia. Yet no drugs currently approved for psychiatric use directly target social behavior...But as researchers have continued to explore the hormone's effect on human behavior, a darker side has emerged. Oxytocin seems to promote aggression or other antisocial behavior in some circumstances. Its effects also appear to vary depending on a person's genetic makeup and psychological status. And no one knows what long-term oxytocin treatment does to the developing human brain. Disconcertingly, one recent study found that male voles treated for several weeks with oxytocin nasal spray around the time of adolescence later exhibited impaired social bonding with females... thus, there is concern about giving oxytocin to children before more is known about the hormone's developmental effects.

...the more recent oxytocin research in humans has frequently found its way into tabloids. In one of the first eye-catching studies in 2005 students who got oxytocin were more trusting...A torrent of studies followed, suggesting that oxytocin not only increases trust and cooperation, but also boosts social perceptiveness, such as face recognition and the ability to read what's on someone's mind from the look in their eyes.

A number of clinical trials suggest oxytocin causes a modest improvement in children and adults with autism, also in social behavior of psychotic patients, but reservations are raised by the vole studies showing early administration of oxytocin disturbs adult bonding and reproductive behavior, and by human studies showing that while it increases altruistic behavior towards in-group individuals, it increases aggression towards out group people.

How our brains judge risk and effort.

Burke et al. do a nice piece of work showing that the risk of an option for action is encoded by the anterior insula and the effort required for that action is coded in mid-cingulate and supplementary motor area. If there is a need to do so, the frontal pole integrates effort and risk costs through functional coupling with the SMA and insula.

Rewards in real life are rarely received without incurring costs and successful reward harvesting often involves weighing and minimizing different types of costs. In the natural environment, such costs often include the physical effort required to obtain rewards and potential risks attached to them. Costs may also include potential risks. In this study, we applied fMRI to explore the neural coding of physical effort costs as opposed to costs associated with risky rewards. Using an incentive-compatible valuation mechanism, we separately measured the subjective costs associated with effortful and risky options. As expected, subjective costs of options increased with both increasing effort and increasing risk. Despite the similar nature of behavioral discounting of effort and risk, distinct regions of the brain coded these two cost types separately, with anterior insula primarily processing risk costs and midcingulate and supplementary motor area (SMA) processing effort costs. To investigate integration of the two cost types, we also presented participants with options that combined effortful and risky elements. We found that the frontal pole integrates effort and risk costs through functional coupling with the SMA and insula. The degree to which the latter two regions influenced frontal pole activity correlated with participant-specific behavioral sensitivity to effort and risk costs. These data support the notion that, although physical effort costs may appear to be behaviorally similar to other types of costs, such as risk, they are treated separately at the neural level and are integrated only if there is a need to do so.

Moral roots of environmental attitudes.

From Feinberg and Willer:

Americans’ attitudes about the environment are highly polarized, but it is unclear why this is the case. We conducted five studies to examine this issue. The first two studies demonstrated that liberals, but not conservatives, view the environment in moral terms and that this tendency partially explains the relation between political ideology and environmental attitudes. The second two studies did content analyses of newspaper op-eds and public-service announcements and found that contemporary environmental discourse is based largely on moral concerns related to harm and care, which are more deeply held by liberals than by conservatives. However, in a final study we found that reframing proenvironmental rhetoric in terms of purity, a moral value resonating primarily among conservatives eliminated the difference between liberals’ and conservatives’ environmental attitudes. These results establish the importance of moralization as a cause of polarization on environmental attitudes and suggest that reframing environmental discourse in different moral terms can reduce the gap between liberals and conservatives in environmental concern.

The Biology of Fear

I want to point to a good open source review article in Current Biology on the brain correlates of fear, by Ralph Adolphs. You might find the summary graphics useful. The summary:

Each of us has felt afraid, and we can all recognize fear in many animal species. Yet there is no consensus in the scientific study of fear. Some argue that ‘fear’ is a psychological construct rather than something discoverable through scientific investigation. Others argue that the term ‘fear’ cannot properly be applied to animals because we cannot know whether they feel afraid. Studies in rodents show that there are highly specific brain circuits for fear, whereas findings from human neuroimaging seem to make the opposite claim. Here, I review the field and urge three approaches that could reconcile the debates. For one, we need a broadly comparative approach that would identify core components of fear conserved across phylogeny. This also pushes us towards the second point of emphasis: an ecological theory of fear that is essentially functional. Finally, we should aim even to incorporate the conscious experience of being afraid, reinvigorating the study of feelings across species.

You are going to die...

The "Opinionator" online commentary feature of the New York Times has another engaging contribution in its "Anxiety" series, from Tim Kreider, author of collections of essays and cartoons. He starts with a visit to a posh retirement community his mother has decided to enter, which she describes as "like a college dorm, except the boys aren't as good-looking." In spite of her enthusiasm, he feels sadness, which he then realizes is mainly selfish, because the family home he grew up in is being sold, the familiar phone number lost. Some clips of sections that struck me:

Plenty of people before me have lamented the way that we in industrialized countries regard our elderly as unproductive workers or obsolete products, and lock them away in institutions instead of taking them into our own homes out of devotion and duty...what I wonder about is what it's doing to the rest of us...I think we also segregate the elderly from the rest of society because we're afraid of them, as if age might be contagious. Which, it turns out, it is.

Segregating the old and the sick enables a fantasy, as baseless as the fantasy of capitalism's endless expansion, of youth and health as eternal, in which old age can seem to be an inexplicably bad lifestyle choice...So that when through absolutely no fault of your own your eyesight begins to blur and you can no longer eat whatever you want without consequence and the hangovers start lasting for days, you feel somehow ripped off, lied to. Aging feels grotesquely unfair. As if there ought to be someone to sue.

Because of all the stories we've absorbed, we vaguely imagine that our lives will take the shape of a narrative - the classic Aristotelian ramp diagram of gradual rising action (struggle and setbacks), climax (happy marriage, professional success), and a brief, cozy denoument (kicking back with family and friends, remembering the good times on a porch someplace pretty). But life is not shaped like a story; it's an elongate and flattened bell curve, with an attenuated, anticlimactic decline as long as its beginning. Friends have described seeing their parents lose their faculties one by one, in more or less the reverse order that their young children are acquiring them.

On the desire for life extension therapies:

I am all for raging against the dying of the light, and if they ever develop DNA rejuvenation or some other longevity technique I will personally claw, throttle and gouge my way through Warren Buffett, Rupert Murdoch and any number of other decrepit billionaires in order to be first in line.

But we don't have a choice. You are older at this moment than you've ever been before, and it's the youngest you're ever going to get. The mortality rate is holding at a scandalous 100 percent. Pretending death can be indefinitely evaded with hot yoga or a gluten-free diet or antioxidants or just by refusing to look is craven denial.

Thoughts as material objects - impact on evaluations

It's hard to get rid of unwanted thoughts. What about just throwing them in the garbage like unwanted objects? In some conditions might we discard our thoughts as easily as we dispose of objects? If Mr. Descartes was right (straw man, I know), a thought cannot literally be thrown into the garbage, because it does not have a material or physical nature. If a component of our cognition is taken to be a physical object, we should be able to discard it. Briñol et al. make some observations relevant to these points. Their experiments involved subjects writing down positive and negative thoughts about their bodies. First, their abstract:

In Western dualistic culture, it is assumed that thoughts cannot be treated as material objects; however, language is replete with metaphorical analogies suggesting otherwise. In the research reported here, we examined whether objectifying thoughts can influence whether the thoughts are used in subsequent evaluations. In a firstexperiment participants wrote about what they either liked or disliked about their bodies. Then, the paper on which they wrote their thoughts was either ripped up and tossed in the trash or kept and checked for errors. When participants physically discarded a representation of their thoughts, they mentally discarded them as well, using them less in forming judgments than did participants who retained a representation of their thoughts. A second experiment replicated this finding and also showed that people relied on their thoughts more when they physically kept them in a safe place—putting their thoughts in their pockets—than when they discarded them. A final study revealed that these effects were stronger when the action was performed physically rather than merely imagined.

Now, a bit more detail on the first experiment:

The experiment was presented as a study on body image. All participants received written instructions asking them to complete several tasks. As part of the first task, each participant was randomly assigned to generate and write down either positive or negative thoughts about his or her own body during a 3-min period. In the positive-thoughts condition, participants were told to list as many positive thoughts about their bodies as they could; in the negative-thoughts condition, participants were told to list as many negative thoughts about their bodies as they could (e.g., Killeya & Johnson, 1998). Examination of the thoughts listed indicated that all participants followed the instructions.

After listing his or her thoughts, each participant was randomly assigned to either the thought-disposal or the control condition. All participants were asked to look back at the thoughts they wrote. In the thought-disposal condition, participants were asked to contemplate their thoughts and then throw them into the trash can located in the room, because their thoughts did not have to remain with them. In the control condition, participants were asked to contemplate their thoughts and to check for any grammar or spelling errors they could find.

The dependent variable in our analysis was participants’ attitudes toward their bodies. Participants were told that they should record these attitudes because their self-image might have influenced their previous responses. Attitudes were assessed using three 9-point semantic-differential scales (e.g., bad-good, unattractive-attractive, like-dislike). Ratings were highly intercorrelated (α = .88), so we averaged them (after reverse scoring as appropriate) to create a composite attitude index. Higher values on this index indicated more favorable attitudes.

From their discussion:

Consistent with our hypothesis that a thought-disposal treatment can influence judgments by invalidating people’s thoughts, results showed that the attitudes of participants who physically threw their thoughts away showed less impact of the thought-direction induction than did the attitudes of participants who physically retained their thoughts....It is important to note that because the treatment was induced after thoughts were already generated, it could not affect the valence or the number of participants’ thoughts. Rather, the treatment decreased the strength of the influence that participants’ thoughts had on their attitudes.

What we should fear...

Gary Marcus does a review of some answers to the annual question of John Brockman's edge.org, "What *should* we be worried about?" On the question of whether we are psychologically and politically constituted to worry about what we most need to worry about, Marcus suggests:

that there is good reason to think that we are not inclined that way, both because of an inherent cognitive bias that makes us focus on immediate concerns (like getting our dishwasher fixed) to the diminishment of our attention to long-term issues (like getting enough exercise to maintain our cardiovascular fitness) and because of a chronic bias toward optimism known as a “just-world fallacy” (the comforting but unrealistic idea that moral actions will invariably lead to just rewards).

A theme throughout the collection is what Stanford psychologist Brian Knutson calls “metaworry”. His metaworry is that:

...actual threats [to our species] are changing much more rapidly than they have in the ancestral past. Humans have created much of this environment with our mechanisms, computers, and algorithms that induce rapid, “disruptive,” and even global change. Both financial and environmental examples easily spring to mind.… Our worry engines [may] not retune their direction to focus on these rapidly changing threats fast enough to take preventative action.

Brain correlates of developing intuition.

An interesting open access study from Wan et al.:

The superior capability of cognitive experts largely depends on automatic, quick information processing, which is often referred to as intuition. Intuition develops following extensive long-term training. There are many cognitive models on intuition development, but its neural basis is not known. Here we trained novices for 15 weeks to learn a simple board game and measured their brain activities in early and end phases of the training while they quickly generated the best next-move to a given board pattern. We found that the activation in the head of caudate nucleus developed over the course of training, in parallel to the development of the capability to quickly generate the best next-move, and the magnitude of the caudate activity was correlated with the subject's performance. In contrast, cortical activations, which already appeared in the early phase of training, did not further change. Thus, neural activation in the caudate head, but not those in cortical areas, tracked the development of capability to quickly generate the best next-move, indicating that circuitries including the caudate head may automate cognitive computations.

A few pictures showing location of the caudate head (pointed to by to line in right figure):

How procrastination gets things done...

John Tierney writes a delightful piece on not getting some things done. He notes several authors' comments on procrastination:

The key to productivity, John Perry argues in “The Art of Procrastination,” is to make more commitments — but to be methodical about it...At the top of your to-do list, put a couple of daunting, if not impossible, tasks that are vaguely important-sounding (but really aren’t) and seem to have deadlines (but really don’t). Then, farther down the list, include some doable tasks that really matter.,,“Doing these tasks becomes a way of not doing the things higher up on the list,” Dr. Perry writes. “With this sort of appropriate task structure, the procrastinator becomes a useful citizen. Indeed, the procrastinator can even acquire, as I have, a reputation for getting a lot done.”

Robert Benchley:

“The secret of my incredible energy and efficiency in getting work done is a simple one,” he wrote. “The psychological principle is this: anyone can do any amount of work, provided it isn’t the work he is supposed to be doing at that moment.”

Piers Steel ("The Procrastination Equation", 2011):

For most of us, procrastination can be beaten down, but not entirely beaten…My best trick is to play my projects off against each other, procrastinating on one by working on another….We are willing to pursue any vile task as long as it allows us to avoid something worse.

Procrastinators rarely sit around absolutely idle. The author Raymond Chandler forced himself to write detective stories by setting aside 4 hours each day with two rules:

a) You don’t have to write.

b) You can’t do anything else.

Another rule from Perry:

Never do today any task that may disappear by tomorrow.

Hedonic adaptation - where did the warm glow go?

Obtaining something we want follows a very stereotyped course, as noted in Oscar Wilde's famous aphorism: "There are only two tragedies in life: one is not getting what one wants, and the other is getting it." Or, consider the scene from the musical "Stop the World, I want to get off." in which the character at the climax of a song are entwined in a happy summation...the music stops...the characters keep holding their position, and keep holding....and keep holding...begin to wobble just a bit...wobble a bit more...and finally fall apart.

Why is the warm glow on attaining some we desire sustained? Why is happily-ever-after so rare? The issue, in terms of relationships, is addressed in Jane Brody recent review of writing and studies on keeping love alive in relationships. The happiness boost that occurs with marriage lasts only about two years, after which people revert to their former levels of happiness - or unhappiness, and infatuation and passion have even shorter life spans. The phenomenon is dubbed "hedonic adaptation" by psychologists - things that thrill us tend to be short-lived. (The reaction of many brain circuits to repeated stimulation is to decrease their reactivity or output, an example being the mesolimbic dopamine system, whose role in the brain reward system is controversial.)

 Lyubomirsky's new book "The Myth of Happiness" deals with this situation and notes techniques, backed by recent research, that help relationships evolve into companionate love, composed more of deep affection, connection and liking (I just downloaded a test sample from Amazon to my iPad to check it out). Barbara L. Fredrickson, author of the forthcoming "Love 2.0" specifies that a flourishing relationship needs three times as many positive emotions as negative ones.

The advice on relationships all seems to boil down to "practice a bit more kindness and gratitude".   I have to say, that when I've been able to budge my curmudgeonly nature enough to actually do this for brief periods of time, it has worked wonders!

How environments talk to genes.

The January issue of Nature Neuroscience has some fascinating articles on gene-environment interactions. Vassoler et al. report that in rats paternal cocaine use causes a heritable increase in cortical brain-derived neurotrophic factor (Bdnf) gene expression, which then confers a cocaine-resistant phenotype in male, but not female, progeny (The sins of the father are forgiven!):

We delineated a heritable phenotype resulting from the self-administration of cocaine in rats. We observed delayed acquisition and reduced maintenance of cocaine self-administration in male, but not female, offspring of sires that self-administered cocaine. Brain-derived neurotrophic factor (Bdnf) mRNA and BDNF protein were increased in the medial prefrontal cortex (mPFC), and there was an increased association of acetylated histone H3 with Bdnf promoters in only the male offspring of cocaine-experienced sires. Administration of a BDNF receptor antagonist (the TrkB receptor antagonist ANA-12) reversed the diminished cocaine self-administration in male cocaine-sired rats. In addition, the association of acetylated histone H3 with Bdnf promoters was increased in the sperm of sires that self-administered cocaine. Collectively, these findings indicate that voluntary paternal ingestion of cocaine results in epigenetic reprogramming of the germline, having profound effects on mPFC gene expression and resistance to cocaine reinforcement in male offspring.

And, Klengel et al. find a molecular mechanism in the case of post-traumatic stress disorder: demethylation of a glucocorticoid response element in the stress response regulator FKBP5 that depends on both the risk allele and childhood trauma. Here is the jargon:

Although the fact that genetic predisposition and environmental exposures interact to shape development and function of the human brain and, ultimately, the risk of psychiatric disorders has drawn wide interest, the corresponding molecular mechanisms have not yet been elucidated. We found that a functional polymorphism altering chromatin interaction between the transcription start site and long-range enhancers in the FK506 binding protein 5 (FKBP5) gene, an important regulator of the stress hormone system, increased the risk of developing stress-related psychiatric disorders in adulthood by allele-specific, childhood trauma–dependent DNA demethylation in functional glucocorticoid response elements of FKBP5. This demethylation was linked to increased stress-dependent gene transcription followed by a long-term dysregulation of the stress hormone system and a global effect on the function of immune cells and brain areas associated with stress regulation. This identification of molecular mechanisms of genotype-directed long-term environmental reactivity will be useful for designing more effective treatment strategies for stress-related disorders.

Our brains change operating modes during an eyeblink.

Nakano et al. suggest that an eye blink briefly gives our attentional network a rest, as activity shifts to the default network:

It remains unknown why we generate spontaneous eyeblinks every few seconds, more often than necessary for ocular lubrication. Because eyeblinks tend to occur at implicit breakpoints while viewing videos, we hypothesized that eyeblinks are actively involved in the release of attention. We show that while viewing videos, cortical activity momentarily decreases in the dorsal attention network after blink onset but increases in the default-mode network implicated in internal processing. In contrast, physical blackouts of the video do not elicit such reciprocal changes in brain networks. The results suggest that eyeblinks are actively involved in the process of attentional disengagement during a cognitive behavior by momentarily activating the default-mode network while deactivating the dorsal attention network.

Why mental arithmetic counts.

Price et al. show that brain activation during single digit arithmetic predicts high school math scores:

Do individual differences in the brain mechanisms for arithmetic underlie variability in high school mathematical competence? Using functional magnetic resonance imaging, we correlated brain responses to single digit calculation with standard scores on the Preliminary Scholastic Aptitude Test (PSAT) math subtest in high school seniors. PSAT math scores, while controlling for PSAT Critical Reading scores, correlated positively with calculation activation in the left supramarginal gyrus and bilateral anterior cingulate cortex, brain regions known to be engaged during arithmetic fact retrieval. At the same time, greater activation in the right intraparietal sulcus during calculation, a region established to be involved in numerical quantity processing, was related to lower PSAT math scores. These data reveal that the relative engagement of brain mechanisms associated with procedural versus memory-based calculation of single-digit arithmetic problems is related to high school level mathematical competence, highlighting the fundamental role that mental arithmetic fluency plays in the acquisition of higher-level mathematical competence.

Lifelong bilingualism enhances cognitive control in aging.

This work by Gold et al. makes me wish I had maintained the proficiency in German that I had in my college years:

Recent behavioral data have shown that lifelong bilingualism can maintain youthful cognitive control abilities in aging. Here, we provide the first direct evidence of a neural basis for the bilingual cognitive control boost in aging. Two experiments were conducted, using a perceptual task-switching paradigm, including a total of 110 participants. In Experiment 1, older adult bilinguals showed better perceptual switching performance than their monolingual peers. In Experiment 2, younger and older adult monolinguals and bilinguals completed the same perceptual task-switching experiment while functional magnetic resonance imaging (fMRI) was performed. Typical age-related performance reductions and fMRI activation increases were observed. However, like younger adults, bilingual older adults outperformed their monolingual peers while displaying decreased activation in left lateral frontal cortex and cingulate cortex. Critically, this attenuation of age-related over-recruitment associated with bilingualism was directly correlated with better task-switching performance. In addition, the lower blood oxygenation level-dependent response in frontal regions accounted for 82% of the variance in the bilingual task-switching reaction time advantage. These results suggest that lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes.

A great New Yorker Cover

I can't resist passing on the cover of the most recent issue of The New Yorker:

Mindfulness neuroscience

The journal Social Cognitive and Affective Neuroscience has released an issue devoted to studies of brain correlates of different kinds of meditation. One article, on compassion or loving-kindness meditation, is open access. For me, the crucial article is the last one, written by a senior guru of the brain imaging field, Michael Posner, and his colleague Yi-Yuan Tang, outlining theoretical and methodological issues in the field. They note that reviews of the field have:

..summarized four components of how mindfulness meditation may work: (i) attention regulation, (ii) body awareness, (iii) emotion regulation (including reappraisal, exposure, extinction and reconsolidation) and (iv) change in perspective on the self. The authors indicate that mindfulness practice comprises a process of enhanced self-regulation that can be differentiated into distinct but interrelated components. While these components are a start, future empirical work should identify additional components of mindfulness and establish to what extent the components involve distinct mechanisms.

Many studies have difficulties with appropriate control and comparison subjects:

Different control and comparison groups have been used in mindfulness research, such as waiting lists, active control groups and interventions designed to match the non-specific effects of mindfulness practices, such as trainer’s confidence, expectancy effects and group support... Ideally, participants would be randomly assigned to condition, and the conditions would be matched with the many non-specific factors that have been found to produce beneficial change... Random assignment allows the changes observed in mindfulness research to be reasonably attributed to the active ingredient of mindfulness practice per se rather than to pre-existing differences in the experimental and control groups. Therefore, moving the field will require the use of rigorous comparison conditions to which participants are randomly assigned.

In long-term studies, an active control is not possible. In studies of long-term practitioners such as monks with many thousands of hours of practice, it is challenging to find even a matched control group. We don’t know how the monks differed before meditation practice and other factors including the environment and low stress, which differ from any ‘matched’ control group.

Other issues are that the various studies employ different mindfulness techniques, stages of practice, or duration of training. (Motivated readers can request a copy of his article from me.)

The power of concentration

I've been meaning to pass on this review by Konnikova on the salutary effects of mindfulness and concentration. It pulls together a number of observations that I have noted in previous MindBlog posts. Here are a few clips:

...mindfulness is less about spirituality and more about concentration: the ability to quiet your mind, focus your attention on the present, and dismiss any distractions that come your way...In 2011, researchers from the University of Wisconsin demonstrated that daily meditation-like thought could shift frontal brain activity toward a pattern that is associated with what cognitive scientists call positive, approach-oriented emotional states — states that make us more likely to engage the world rather than to withdraw from it...

An exercise in mindfulness can also help with that plague of modern existence: multitasking...researchers led by a team from the University of Washington examined the effects of meditation training on multitasking in a real-world setting. They asked a group of human resources professionals to engage in the type of simultaneous planning they did habitually... After the multitasking free-for-all, participants were divided into three groups: one was assigned to an eight-week meditation course (two hours of instruction, weekly); another group didn’t take the course at first, but took it later; and the last group took an eight-week course in body relaxation. Everyone was put through a second round of frenzy...The only participants to show improvement were those who had received the mindfulness training.Not only did they report fewer negative emotions at the end of the assignment, but their ability to concentrate improved significantly. They could stay on task longer and they switched between tasks less frequently.

In recent years, mindfulness has been shown to improve connectivity inside our brain’s attentional networks, as well as between attentional and medial frontal regions — changes that save us from distraction. Mindfulness, in other words, helps our attention networks communicate better and with fewer interruptions than they otherwise would...In 2006, a team of psychologists demonstrated that the neural activation patterns of older adults (specifically, activation in the prefrontal cortex), began to resemble those of much younger subjects after just five one-hour training sessions on a task of attentional control. Their brains became more efficient at coordinating multiple tasks — and the benefit transferred to untrained activities, suggesting that it was symptomatic of general improvement.

Similar changes have been observed in the default network (the brain’s resting-state activity). In 2012, researchers from Ohio State University demonstrated that older adults who scored higher on mindfulness scales had increased connectivity in their default networks, specifically in two of the brain’s major information processing hubs. And while we already know that this kind of increased connectivity is a very good thing, there’s more to these particular results. The precise areas that show increased connectivity with mindfulness are also known to be pathophysiological sites of Alzheimer’s disease.

Self affirmation enhances responsiveness to errors.

Legault et al. note brain responses that correlate with augmented attention and emotional receptivity to performance errors caused by enhanced self affirmation. The experiments used the usual group of undergraduate psychology students, who were split into two groups given writing exercises designed to either enhance or undermine self-affirmation. Both groups then performed a simple go, no-go exercise, with errors getting negative feedback. EEG recordings were made during this exercise. Here is their summary extract:

Self-affirmation produces large effects: Even a simple reminder of one’s core values reduces defensiveness against threatening information. But how, exactly, does self-affirmation work? We explored this question by examining the impact of self-affirmation on neurophysiological responses to threatening events. We hypothesized that because self-affirmation increases openness to threat and enhances approachability of unfavorable feedback, it should augment attention and emotional receptivity to performance errors. We further hypothesized that this augmentation could be assessed directly, at the level of the brain. We measured self-affirmed and nonaffirmed participants’ electrophysiological responses to making errors on a task. As we anticipated, self-affirmation elicited greater error responsiveness than did nonaffirmation, as indexed by the error-related negativity, a neural signal of error monitoring. Self-affirmed participants also performed better on the task than did nonaffirmed participants. We offer novel brain evidence that self-affirmation increases openness to threat and discuss the role of error detection in the link between self-affirmation and performance.

Music and movement: shared dynamic structure in universal expressions of emotion

Sievers et al. do a fascinating analysis. They designed an ingenious computer program that used slider bars to adjust a music player or a bouncing ball with varying rate, jitter (regularity of rate), direction, step size, and dissonance/visual spikiness. Participants were instructed to take as much time as needed to set the sliders in the program to express five emotions: “angry,” “happy,” “peaceful,” “sad,” and “scared.” One set of participants was instructed to move sliders to express the emotion with the moving ball, then other set told to move the sliders to use music to express the emotion. U.S. college students were one experimental group, the other was a culturally isolated Kreug ethnic minority in northern Cambodia with music formally dissimilar to Western music: no system of vertical pitch relations equivalent to Western tonal harmony, constructed using different scales and tunings, and performed on morphologically dissimilar instruments. Here is the authors' summary abstract:

Music moves us. Its kinetic power is the foundation of human behaviors as diverse as dance, romance, lullabies, and the military march. Despite its significance, the music-movement relationship is poorly understood. We present an empirical method for testing whether music and movement share a common structure that affords equivalent and universal emotional expressions. Our method uses a computer program that can generate matching examples of music and movement from a single set of features: rate, jitter (regularity of rate), direction, step size, and dissonance/visual spikiness. We applied our method in two experiments, one in the United States and another in an isolated tribal village in Cambodia. These experiments revealed three things: (i) each emotion was represented by a unique combination of features, (ii) each combination expressed the same emotion in both music and movement, and (iii) this common structure between music and movement was evident within and across cultures.

The End of History Illusion.

The Jan 4 issue of Science has an interested article by Quoidbach et al. on our perception of how much we changed in the past decade and how much we expect to change in the next. Here is some context from their introduction:

At every stage of life, people make decisions that profoundly influence the lives of the people they will become—and when they finally become those people, they aren’t always thrilled about it. Young adults pay to remove the tattoos that teenagers paid to get, middle-aged adults rush to divorce the people whom young adults rushed to marry, and older adults visit health spas to lose what middle-aged adults visited restaurants to gain. Why do people so often make decisions that their future selves regret? One possibility is that people have a fundamental misconception about their future selves. Time is a powerful force that transforms people’s preferences, reshapes their values, and alters their personalities, and we suspect that people generally underestimate the magnitude of those changes. In other words, people may believe that who they are today is pretty much who they will be tomorrow, despite the fact that it isn’t who they were yesterday. In the studies we describe here, we showed that people expect to change little in the future, despite knowing that they have changed a lot in the past, and that this tendency bedevils their decision-making. We call this tendency to underestimate the magnitude of future change the “end of history illusion.”

And here is their summary and discussion:

Across six studies of more than 19,000 participants, we found consistent evidence to indicate that people underestimate how much they will change in the future, and that doing so can lead to suboptimal decisions. Although these data cannot tell us what causes the end of history illusion, two possibilities seem likely. First, most people believe that their personalities are attractive, their values admirable, and their preferences wise (10); and having reached that exalted state, they may be reluctant to entertain the possibility of change. People also like to believe that they know themselves well (11), and the possibility of future change may threaten that belief. In short, people are motivated to think well of themselves and to feel secure in that understanding, and the end of history illusion may help them accomplish these goals.

Second, there is at least one important difference between the cognitive processes that allow people to look forward and backward in time (12). Prospection is a constructive process, retrospection is a reconstructive process, and constructing new things is typically more difficult than reconstructing old ones (13, 14). The reason this matters is that people often draw inferences from the ease with which they can remember or imagine (15, 16). If people find it difficult to imagine the ways in which their traits, values, or preferences will change in the future, they may assume that such changes are unlikely. In short, people may confuse the difficulty of imagining personal change with the unlikelihood of change itself.

Although the magnitude of this end of history illusion in some of our studies was greater for younger people than for older people, it was nonetheless evident at every stage of adult life that we could analyze. Both teenagers and grandparents seem to believe that the pace of personal change has slowed to a crawl and that they have recently become the people they will remain. History, it seems, is always ending today.

Surprise! Satisfied old folks live longer.

Contra a popular assumption that feisty, grumpy old farts are likely to live longer than sweet docile passive ones, Judith Graham reviews recent work by Becca Levy, an associate professor of epidemiology and psychology at Yale University that suggests the opposite - basically that older people become what they think, what their age stereotypes are. Some edited clips:

She looked at a a database of 660 adults age 50 and older in Oxford, Ohio, who were followed for a period of 23 years, from 1975 to 1998, and reported in The Journal of Personal and Social Psychology in 2002 that those with positive age stereotypes lived 7.5 years longer than those with negative stereotypes. She also did a series of laboratory experiments with older people, exposing them subliminally to negative or positive stereotypes by flashing words associated with aging on a computer screen too fast for them to process consciously. Then these seniors were asked to perform a task. Those exposed to negative words such as "decrepit" had poorer handwriting, slower walking speeds, higher levels of cardiovascular stress and a greater willingness to reject hypothetical medical interventions that could prolong their lives. Those primed with positive words such as "wisdom" did much better.

Levy established that people with positive age stereotypes were more likely to eat a balanced diet, exercise, limit their alcohol consumption, stop smoking and get regular physical exams, and that they had a higher level of physical functioning over time. Results were controlled for other factors like illness, gender, race and socioeconomic status…In these papers, Dr. Levy hypothesized that positive age stereotypes are associated with a greater sense of control and that this enhanced seniors' sense of self efficacy -- their ability to remain captains of their own ship, as it were.

Human evolution: endurance running made our brains larger and smarter.

Gretchen Reynolds reviews work suggesting that our advanced cleverness and big brains may have come not from the need to think but becoming endurance athletes, able to bring down swifter prey through sheer doggedness, jogging and plodding along behind them until the animals dropped. It turns out our larger brain size with respect to body size is also shown to some extent by species like dogs and rats that have a high innate endurance capacity, presumably evolved over millennia. it is also seen in mice and rats systematically bred to be marathon runners. After multiple generations, these animals begin to develop innately higher levels of tissue growth and health promoters, including the protein brain-derived neurotrophic factor, or BDNF. These substances are important for endurance performance. They also are known to drive brain growth. Such observations have led Raichlen and Polk to suggest that physical activity may have helped to make early humans smarter:

The hunting and gathering lifestyle adopted by human ancestors around 2 Ma required a large increase in aerobic activity. High levels of physical activity altered the shape of the human body, enabling access to new food resources (e.g. animal protein) in a changing environment. Recent experimental work provides strong evidence that both acute bouts of exercise and long-term exercise training increase the size of brain components and improve cognitive performance in humans and other taxa. However, to date, researchers have not explored the possibility that the increases in aerobic capacity and physical activity that occurred during human evolution directly influenced the human brain. Here, we hypothesize that proximate mechanisms linking physical activity and neurobiology in living species may help to explain changes in brain size and cognitive function during human evolution. We review evidence that selection acting on endurance increased baseline neurotrophin and growth factor signalling (compounds responsible for both brain growth and for metabolic regulation during exercise) in some mammals, which in turn led to increased overall brain growth and development. This hypothesis suggests that a significant portion of human neurobiology evolved due to selection acting on features unrelated to cognitive performance.

Why are older people more susceptible to fraud?

From Castle et al: a succinct set of observations. Their data is quite compelling.

Older adults are disproportionately vulnerable to fraud, and federal agencies have speculated that excessive trust explains their greater vulnerability. Two studies, one behavioral and one using neuroimaging methodology, identified age differences in trust and their neural underpinnings. Older and younger adults rated faces high in trust cues similarly, but older adults perceived faces with cues to untrustworthiness to be significantly more trustworthy and approachable than younger adults. This age-related pattern was mirrored in neural activation to cues of trustworthiness. Whereas younger adults showed greater anterior insula activation to untrustworthy versus trustworthy faces, older adults showed muted activation of the anterior insula to untrustworthy faces. The insula has been shown to support interoceptive awareness that forms the basis of “gut feelings,” which represent expected risk and predict risk-avoidant behavior. Thus, a diminished “gut” response to cues of untrustworthiness may partially underlie older adults’ vulnerability to fraud.

Body resonance and art appreciation.

Leder et al. have asked how hand movements reflected two styles of painting having similar content and historic period might interact with muscle movements in the viewer to influence their appreciation of the painting. Their introduction gives a bit of context for the work:

The question of how art creates aesthetic pleasure has puzzled researchers since the early days of psychology... In the visual arts, the common belief is that perceptual features, such as contrast or color, determine aesthetic pleasure; one mechanism underlying this perceptual path has been identified as processing efficiency... By contrast, since the late 19th century, the Empathists’ movement has claimed that a substantial source of aesthetic pleasure is empathy with the artwork... More precisely, Lee..argued that such empathy may result from episodes of sympathetic resonance of the perceiver’s own body with the artwork he or she is viewing. Currie...distinguished different kinds of resonance occurring through structures specifically responsible for motor processing, emotional responses, and even metaphorical word-action relations. Regarding motor simulations, Freedberg and Gallese..speculated that viewing artwork may activate neural movement programs associated with the way the artwork was produced ... Thus, one source of aesthetic empathy and thus aesthetic pleasure may stem from body resonances (of the perceiver’s body) with the movements that the artist made when producing the work.

They started with the view that perceiving a painting style elicits covert simulations of concordant hand movements in the viewer and that these stimulus-triggered simulations might be enhanced or interfered with by simultaneously performing hand movements that either resemble or do not resemble, respectively, the movements the artist made while creating the paintings... Making such movements might increase or decrease aesthetic appreciation, respectively, in the viewer...

Indeed, they found that when subjects were instructed to tap an eraser tip out of their view on the table top at their own pace (the motion used the stippling of pointillism), on viewing a series of pictures they preferred pointillist painting over stroke-style paintings. Instruction to move a pen out of view in strokes of about 20 cm from left to right on the table’s surface produced a preference for stroke-style paintings.

They showed that the movements were essential to the aesthetic episode of perceiving and evaluating the artwork by doing the control of have subjects perform matching or mismatching hand movements before viewing the artwork. This did not influence their art appreciation.

Lévi-Strauss - "shattered hologram" of aging.

I've been having a go at Jim Holt's popular book  "Why does the world exist? An existential detective story."  After three chapters of fascinating quotes from famous ancient and modern philosophers and scientists I skipped to the epilogue, and found a striking account given by the author of attending a small party at the Collège de France in celebration of the ninetieth birthday of Claude Lévi-Strauss. Lévi-Strauss was asked to give a little speech to the group, and begins with:

"Montaigne said that aging diminishes us each day in a way that, when death finally arrives, it takes away only a quarter or half the man. But Montaigne only lived to be fifty-nine, so he could have no idea of the extreme old age I find myself in today" - which, he adds, was one of the "most curious surprises of my existence."  He says he feels like a "shattered hologram" that has lost its unity but that still retains an image of the whole self. 

Lévi-Strauss goes on to talk about the "dialogue"  between the eroded self he has become - le moi réel - and the ideal self that coexists with it - le moi métronymique.  The latter, planning ambitious new intellectual projects, says to the former,  "You must continue."  But the former replies, "That's your business - only you can see things whole."  Levi-Strauss then thanks those of us assembled for helping him silence this futile dialogue and allowing his two selves of "coincide" again for a moment - "although," he adds,  "I am well aware that le moi réel will continue to sink toward its ultimate dissolution."

What an incredible description of what we experience as we continually loose our brain cells during aging: a receding shadow of the richness of the world once integrated by their antecedent and larger ensemble.

The final lines of Holt's epilogue, and the book:

Philosophy, n. A route of many roads leading from nowhere to nothing.

-AMBROSE BIERCE, The Devil's Dictionary