Monday, December 31, 2012

A usefull trick: Shifting attention to reduce emotional reactivity.

Thiruchselvam et al. do a simple demonstration of how our introspective attention can regulate our emotions after an unpleasant for fearful stimulus. Shifting the focus of that subsequent attention away from the challenging part of the image lessens emotional reactivity.  Here is their abstract, following by the basic experimental protocol:

Selective attention plays a fundamental role in emotion regulation. To date, research has examined individuals’ use of selective attention to regulate emotional responses during stimulus presentation. In the present study, we examined whether selective attention can be used to regulate emotional responses during a poststimulus period when representations are active within working memory (WM). On each trial, participants viewed either a negative or a neutral image. After the offset of the image, they maintained a representation of it in WM and were cued to focus their attention on either neutral or arousing aspects of that representation. Results showed that, relative to focusing on an arousing portion of a negative-image representation within WM, focusing on a neutral portion of the representation reduced both self-reported negative emotion and the late positive potential, a robust neural measure of emotional reactivity. These data suggest that selective attention can alter emotional responses arising from affective representations active within WM.


Figure (click to enlarge): Illustration of the trial structure. After an initial fixation period, an image (either negative or neutral) appeared on-screen for 1,500 ms. Then, two circles were overlaid on the image for 1,500 ms. For negative images (as shown here), one circle highlighted a neutral portion, whereas the other circle highlighted an arousing portion. For neutral images, both circles highlighted neutral portions. The image then disappeared, leaving a black screen for 750 ms, during which participants held the full image in working memory. Then, one of the circles was presented briefly for 250 ms. In the subsequent 3,000-ms interval, participants had to focus their attention on the portion of the image that had previously been contained within the target circle. Participants then rated how pleasant or unpleasant they felt.

Monday, December 24, 2012

Happy Holidays - a personal note - and MindBlog taking a break

My partner Len and I have traveled from our Fort Lauderdale snowbird retreat to Austin Texas to join  my ex-wife Marilyn Young, son Jonathan Bownds, daughter-in-law Shana Merlin, and my first grandchild, their new 9 month old grandson Sebastian.   They are now living in the Bownds family home that now has sheltered four generations of the Bownds family.  Daughter Sarah Bownds from Madison is also here.

Training parts of your brain for perceptual enhancement.

Geraint Rees and collaborators have done some fascinating work showing that training the spontaneous activity of just a part of our visual brain, corresponding to just a part of our visual field, can enhance the visual performance of that part of our vision:

Perception depends on the interplay of ongoing spontaneous activity and stimulus-evoked activity in sensory cortices. This raises the possibility that training ongoing spontaneous activity alone might be sufficient for enhancing perceptual sensitivity. To test this, we trained human participants to control ongoing spontaneous activity in circumscribed regions of retinotopic visual cortex using real-time functional MRI-based neurofeedback. After training, we tested participants using a new and previously untrained visual detection task that was presented at the visual field location corresponding to the trained region of visual cortex. Perceptual sensitivity was significantly enhanced only when participants who had previously learned control over ongoing activity were now exercising control and only for that region of visual cortex. Our new approach allows us to non-invasively and non-pharmacologically manipulate regionally specific brain activity and thus provide “brain training” to deliver particular perceptual enhancements.

Friday, December 21, 2012

For guys who want to attract women?

Perhaps there is a human equivalent of the non-volatile protein pheromone darcin, that Roberts et al. show to stimulate spatial preference and learning in mice. Female mice preferred locations where male urine (or synthesized darcin) had been found, and remembered these spatial locations for 2 weeks post-exposure. (Scent marking is an essential component of communication for most mammals. Individuals remember the location of scent marks and regularly revisit marked sites, presumably to assess the condition and status of the animal doing the marking. It is known that individuals can follow odor or pheromone gradients to locate another individual, but relocating scent marks is a much more difficult task given the small amount of volatile compounds deposited, and their static nature.) Here is the abstract:

Many mammals use scent marking for sexual and competitive advertisement, but little is known about the mechanism by which scents are used to locate mates and competitors. We show that darcin, an involatile protein sex pheromone in male mouse urine, can rapidly condition preference for its remembered location among females and competitor males so that animals prefer to spend time in the site even when scent is absent. Learned spatial preference is conditioned through contact with darcin in a single trial and remembered for approximately 14 days. This pheromone-induced learning allows animals to relocate sites of particular social relevance and provides proof that pheromones such as darcin can be highly potent stimuli for social learning.

Thursday, December 20, 2012

Unconscious reading and arithmetic.

Here is a fascinating bit from Sklar et al.:

The modal view in the cognitive and neural sciences holds that consciousness is necessary for abstract, symbolic, and rule-following computations. Hence, semantic processing of multiple-word expressions, and performing of abstract mathematical computations, are widely believed to require consciousness. We report a series of experiments in which we show that multiple-word verbal expressions can be processed outside conscious awareness and that multistep, effortful arithmetic equations can be solved unconsciously. All experiments used Continuous Flash Suppression to render stimuli invisible for relatively long durations (up to 2,000 ms). Where appropriate, unawareness was verified using both objective and subjective measures. The results show that novel word combinations, in the form of expressions that contain semantic violations, become conscious before expressions that do not contain semantic violations, that the more negative a verbal expression is, the more quickly it becomes conscious, and that subliminal arithmetic equations prime their results. These findings call for a significant update of our view of conscious and unconscious processes.
(note:  Continuous Flash Suppression consists of a presentation of a target stimulus to one eye and a simultaneous presentation of rapidly changing masks to the other eye. The rapidly changing masks dominate awareness until the target breaks into consciousness. This suppression may last seconds. To examine arithmetic, another symbolic, rule-following system, the authors moved from a breaking-into-consciousness design to a priming design. They examined the effects of subliminal stimuli on conscious stimuli that follow them, using both subjective and objective measures to verify the subliminality of the primes.)

Wednesday, December 19, 2012

Grin and bear it.

Kraft and Pressman make a nice observation on linking muscle movement to emotion, showing how manipulating the muscles involved in a smile can alter the stress response:

In the study reported here, we investigated whether covertly manipulating positive facial expressions would influence cardiovascular and affective responses to stress. Participants (N = 170) naive to the purpose of the study completed two different stressful tasks while holding chopsticks in their mouths in a manner that produced a Duchenne smile, a standard smile, or a neutral expression. Awareness was manipulated by explicitly asking half of all participants in the smiling groups to smile (and giving the other half no instructions related to smiling). Findings revealed that all smiling participants, regardless of whether they were aware of smiling, had lower heart rates during stress recovery than the neutral group did, with a slight advantage for those with Duchenne smiles. Participants in the smiling groups who were not explicitly asked to smile reported less of a decrease in positive affect during a stressful task than did the neutral group. These findings show that there are both physiological and psychological benefits from maintaining positive facial expressions during stress.

Tuesday, December 18, 2012

Brain plasticity induced by musical training.

As a lifelong pianist, I have always regarded with awe pianists like Horowitz and Rubenstein who have continued to perform into into their advanced old age. I have done some 4 hands recitals here in my winter nest of Fort Lauderdale with an 87-year old retired music professor and performer who still gives solo concerts. Musical performance makes very complex demands on visual, auditory, and motor processing. Numerous studies have shown that subcortical and cortical brain regions can change with musical training. Hernholz and Zatorre offer a massive review of musical training as a framework for brain plasticity in a recent issue of Neuron. I can't even begin to summarize the abundant material presented and offer only the abstract and one sample figure here (motivated readers can request a PDF of the article from me.)

Musical training has emerged as a useful framework for the investigation of training-related plasticity in the human brain. Learning to play an instrument is a highly complex task that involves the interaction of several modalities and higher-order cognitive functions and that results in behavioral, structural, and functional changes on time scales ranging from days to years. While early work focused on comparison of musical experts and novices, more recently an increasing number of controlled training studies provide clear experimental evidence for training effects. Here, we review research investigating brain plasticity induced by musical training, highlight common patterns and possible underlying mechanisms of such plasticity, and integrate these studies with findings and models for mechanisms of plasticity in other domains.


Figure 2 (click to enlarge). Interindividual Differences in Auditory Cortical Structure and Function(A) Variability in auditory cortex gray matter concentration and cortical thickness predicted performance on a melodic transposition task (adapted from Foster and Zatorre, 2010).(B) Different rates of behavioral improvement during pitch memory training were accompanied by differential training-related functional changes in secondary auditory areas (adapted from Gaab et al., 2006).(C) BOLD signal covariation to increasing pitch size in microtonal melodies prior to training in both left and right auditory cortices was predictive of the speed with which learning occurred, such that those individuals who subsequently learned more quickly had an initially steeper response function (adapted from Zatorre et al., in press).

Monday, December 17, 2012

The herding hormone

Yet another addition, from Stallen et al., to the long list of studies on oxytocin and our social behaviors (enter oxytocin in the search box in the left column to pull up the numerous mindblog posts on oxytocin effects on our behaviors):

People often conform to others with whom they associate. Surprisingly, however, little is known about the possible hormonal mechanisms that may underlie in-group conformity. Here, we examined whether conformity toward one’s in-group is altered by oxytocin, a neuropeptide often implicated in social behavior. After administration of either oxytocin or a placebo, participants were asked to provide attractiveness ratings of unfamiliar visual stimuli. While viewing each stimulus, participants were shown ratings of that stimulus provided by both in-group and out-group members. Results demonstrated that on trials in which the ratings of the in-group and out-group were incongruent, the ratings of participants given oxytocin conformed to the ratings of their in-group but not of their out-group. Participants given a placebo did not show this in-group bias. These findings indicate that administration of oxytocin can influence subjective preferences, and they support the view that oxytocin’s effects on social behavior are context dependent.

Friday, December 14, 2012

Brain imaging of the positive bias we place on social feedback.

Continuing the social brain thread started by yesterday's post, I pass on this piece by Korn et al. showing brain correlates of the rose colored glasses we put on interpreting social feedback from others. Participants in the study rated how much 40 positive and 40 negative trait adjectives applied to themselves and to one other person before and after receiving feedback ratings of themselves. The critical test for positively biased updating was finding that the changes toward desirable feedback were larger than the changes toward undesirable feedback. Here is their abstract:

Receiving social feedback such as praise or blame for one's character traits is a key component of everyday human interactions. It has been proposed that humans are positively biased when integrating social feedback into their self-concept. However, a mechanistic description of how humans process self-relevant feedback is lacking. Here, participants received feedback from peers after a real-life interaction. Participants processed feedback in a positively biased way, i.e., they changed their self-evaluations more toward desirable than toward undesirable feedback. Using functional magnetic resonance imaging we investigated two feedback components. First, the reward-related component correlated with activity in ventral striatum and in anterior cingulate cortex/medial prefrontal cortex (ACC/MPFC). Second, the comparison-related component correlated with activity in the mentalizing network, including the MPFC, the temporoparietal junction, the superior temporal sulcus, the temporal pole, and the inferior frontal gyrus. This comparison-related activity within the mentalizing system has a parsimonious interpretation, i.e., activity correlated with the differences between participants' own evaluation and feedback. Importantly, activity within the MPFC that integrated reward-related and comparison-related components predicted the self-related positive updating bias across participants offering a mechanistic account of positively biased feedback processing. Thus, theories on both reward and mentalizing are important for a better understanding of how social information is integrated into the human self-concept.

Thursday, December 13, 2012

Enhancing social ability with brain stimulation.

Social information is thought to be processed by a specific set of neural circuits often referred to as the ‘social brain’ The figure shows localization in human brains of the relevant temporo-parietal junction orbitofrontal cortex in lateral (top) and medial (bottom) views.  Santiesteban et al. now show that low levels of direct current stimulation of the temporoparietal junction region improves control of self-other representations. (The electrical stimulation is two saline-soaked surface sponge electrodes driven by a battery driven constant low current stimulator). Here is their summary, followed by the abstract:
-OFC neurons respond to social visual stimul
-OFC neurons differentiate between socially defined classes of images
-OFC neurons signal the value of social information for making decisions
-More OFC neurons convey social information than fluid reward magnitude.
Primate evolution produced an increased capacity to respond flexibly to varying social contexts as well as expansion of the prefrontal cortex [1,2]. Despite this association, how prefrontal neurons respond to social information remains virtually unknown. People with damage to their orbitofrontal cortex (OFC) struggle to recognize facial expressions [3,4], make poor social judgments [5,6], and frequently make social faux pas [7,8]. Here we test explicitly whether neurons in primate OFC signal social information and, if so, how such signals compare with responses to primary fluid rewards. We find that OFC neurons distinguish images that belong to socially defined categories, such as female perinea and faces, as well as the social dominance of those faces. These modulations signaled both how much monkeys valued these pictures and their interest in continuing to view them. Far more neurons signaled social category than signaled fluid value, despite the stronger impact of fluid reward on monkeys’ choices. These findings indicate that OFC represents both the motivational value and attentional priority of other individuals, thus contributing to both the acquisition of information about others and subsequent social decisions. Our results betray a fundamental disconnect between preferences expressed through overt choice, which were primarily driven by the desire for more fluid, and preferential neuronal processing, which favored social computations.

Wednesday, December 12, 2012

Thanks for not sharing, and tuning out...

I almost did a post last week on Roger Cohen's NYTimes 'thank you for not sharing' piece , and now he has done a followup on tuning out, so I can't resist passing on a few choice clips. From the first piece:

LET us ponder oversharing and status anxiety, the two great scourges of the modern world.
What is this compulsion to share? Sometimes, of course, it is just a mistake, the wrong button hit, or mishandling of privacy settings on Facebook. But there is a new urge to behave as if life were some global high-school reunion at which everyone has taken some horrific tell-all drug.
My theory is this. Humanity has always been hardwired to fear. That is how we survived. But the fear used to be of wild beasts prowling, the encroaching Visigoths, plague, world war. Now, in the pampered present, all that anxiety has to find a new focus. So, having searched long and hard, and helped by technology, we have come up with being anxious that our status might be falling or — the horror, the horror! — disintegrating.
Number of Twitter followers shrinking or not growing as fast as your friends’? Status anxiety attack begins. No e-mails or texts received in the past 78 minutes? Status anxiety attack accelerates. Got unfriended or discover by chance on LinkedIn that your 29-year-old college roommate is now running an agribusiness fund out of St. Louis that has assets of $47 billion and owns half of Madagascar? Status meltdown kicks in.
The only antidote, the only means to push that status up again, it seems, is to keep sharing more and more. Here I am — the posts and tweets and pix say — a being not anonymous but alive. I overshare therefore I am.
And from the second:
...we are not the first humans to believe the world has sped up and hyperconnected to a point where distance has been eliminated. Too often we confuse activity and movement with accomplishment and fulfillment. More may be gained through a pause...We tend to overstate what has changed. The fundamental instincts and urges of our natures remain constant. Social media did not invent the need to be loved or the fear of being unloved. They just revealed them in new ways...It is the culture of oversharing and status anxiety that disturbs me. And that is inseparable from the grip of social media.
...like Facebook, Twitter can be addictive in ways that may provide brief solace but militate against respect of our deeper natures. There is too much noise, too little silence. To share, that once beautiful verb, has become an awful emotional splurge...The friend-follower conceits are brilliant marketing tools designed to play on insecurities. Who does not want more friends and more followers? Who does not feel the sleight of being unfriended or unfollowed, a settling of scores more impersonal than a duel and perhaps crueler for that?
...here’s to doses of disconnection in 2013. Get out of the cross hairs of your devices from time to time. Drink experience unfiltered by hyperconnection. Gaze with patience. Listen through silences. Let your longings breathe...Somewhere deep inside everyone is the thing that makes them tick. The thing is it is often well hidden. The psyche builds layers of protection around people’s most vulnerable traits, which may be closely linked to their precious essence. Social media build layers of distraction from that essence.

Tuesday, December 11, 2012

Living without irony?

I've been wanting to pass on this marvelous essay by Christy Wampole, which bemoans the ironic sensibility that pervades our culture, and wonders whether there is any escape. Some clips:

For many Americans born in the 1980s and 1990s - members of Generation Y, or Millennials - particularly middle-class Caucasians, irony is the primary mode with which daily life is dealt. One need only dwell in public space, virtual or concrete, to see how pervasive this phenomenon has become…Take, for example, an ad that calls itself an ad, makes fun of its own format, and attempts to lure its target market to laugh at and with it. It pre-emptively acknowledges its own failure to accomplish anything meaningful. No attack can be set against it, as it has already conquered itself.
How did this happen? It stems in part from the belief that this generation has little to offer in terms of culture, that everything has already been done, or that serious commitment to any belief will eventually be subsumed by an opposing belief, rendering the first laughable at best and contemptible at worst. This kind of defensive living works as a pre-emptive surrender and takes the form of reaction rather than action…While we have gained some skill sets (multitasking, technological savvy), other skills have suffered: the art of conversation, the art of looking at people, the art of being seen, the art of being present. Our conduct is no longer governed by subtlety, finesse, grace and attention, all qualities more esteemed in earlier decades. Inwardness and narcissism now hold sway.
I, too, exhibit ironic tendencies. For example, I find it difficult to give sincere gifts. Instead, I often give what in the past would have been accepted only at a White Elephant gift exchange. Good for a chuckle in the moment, but worth little in the long term. Something about the responsibility of choosing a personal, meaningful gift for a friend feels too intimate, too momentous. I somehow cannot bear the thought of a friend disliking a gift I'd chosen with sincerity. The simple act of noticing my self-defensive behavior has made me think deeply about how potentially toxic ironic posturing could be.
Fundamentalists are never ironists; dictators are never ironists; people who move things in the political landscape, regardless of the sides they choose, are never ironists….Where can we find other examples of nonironic living? What does it look like? Nonironic models include very young children, elderly people, deeply religious people, people with severe mental or physical disabilities, people who have suffered, and those from economically or politically challenged places where seriousness is the governing state of mind. My friend Robert Pogue Harrison put it this way in a recent conversation: "Wherever the real imposes itself, it tends to dissipate the fogs of irony."
The ironic life is certainly a provisional answer to the problems of too much comfort, too much history and too many choices, but it is my firm conviction that this mode of living is not viable and conceals within it many social and political risks. For such a large segment of the population to forfeit its civic voice through the pattern of negation I've described is to siphon energy from the cultural reserves of the community at large. People may choose to continue hiding behind the ironic mantle, but this choice equals a surrender to commercial and political entities more than happy to act as parents for a self-infantilizing citizenry. So rather than scoffing at the hipster - a favorite hobby, especially of hipsters - determine whether the ashes of irony have settled on you as well. It takes little effort to dust them away.

Monday, December 10, 2012

Hindsight bias.

Regarding the recent presidential election, do you feel that you knew the outcome in your gut all along? Not only felt it coming, but are sure you predicted it beforehand? I did. (But, when I honestly look back, I was totally prepared for a Romney win, and ready to say I had predicted that all along...). In this recent article, Roese and Vohs do a nice dissection of this phenomenon:

Hindsight bias occurs when people feel that they “knew it all along,” that is, when they believe that an event is more predictable after it becomes known than it was before it became known. Hindsight bias embodies any combination of three aspects: memory distortion, beliefs about events’ objective likelihoods, or subjective beliefs about one’s own prediction abilities. Hindsight bias stems from (a) cognitive inputs (people selectively recall information consistent with what they now know to be true and engage in sensemaking to impose meaning on their own knowledge), (b) metacognitive inputs (the ease with which a past outcome is understood may be misattributed to its assumed prior likelihood), and (c) motivational inputs (people have a need to see the world as orderly and predictable and to avoid being blamed for problems). Consequences of hindsight bias include myopic attention to a single causal understanding of the past (to the neglect of other reasonable explanations) as well as general overconfidence in the certainty of one’s judgments. New technologies for visualizing and understanding data sets may have the unintended consequence of heightening hindsight bias, but an intervention that encourages people to consider alternative causal explanations for a given outcome can reduce hindsight bias.

Friday, December 07, 2012

We use body cues, not facial expression, to discriminate intense positive and negative emotions.

Interesting work from Aviezer et al:

The distinction between positive and negative emotions is fundamental in emotion models. Intriguingly, neurobiological work suggests shared mechanisms across positive and negative emotions. We tested whether similar overlap occurs in real-life facial expressions. During peak intensities of emotion, positive and negative situations were successfully discriminated from isolated bodies but not faces. Nevertheless, viewers perceived illusory positivity or negativity in the nondiagnostic faces when seen with bodies. To reveal the underlying mechanisms, we created compounds of intense negative faces combined with positive bodies, and vice versa. Perceived affect and mimicry of the faces shifted systematically as a function of their contextual body emotion. These findings challenge standard models of emotion expression and highlight the role of the body in expressing and perceiving emotions.

Thursday, December 06, 2012

MindBlog is trying a new brain fitness app

It has been a few years since I have reviewed brain fitness exercises of the sort claimed to enhance working memory and general intelligence (g). A new generation of Apps has appeared, and one - CogniFit Brain Fitness for the iPhone and iPad - gets a brief review in the iPhone App Review. The price is right (It's free), and here is a brief clip from the review:

...fun mind games in the form of visual puzzles are presented for free to each user; such games include jigsaw puzzles, mahjong, “words birds,” and “whack a mole.” Specific skills are tested during each game. For example, the jigsaw challenges are designed to hone users’ updating, focusing, and visual scanning skills while “whack a mole” is built to improve cognitive skills such as divided attention, working memory, planning, and spatial perception. While each game in this app focuses on providing different challenges, all of the games are similar in the way that they increase in difficulty as a player advances through the various levels.
I've put the App on my iPhone and iPad, and will be curious to see whether I get hooked on it. I certainly faded fast on my brief flirtation with N-back game Apps several years ago. I would welcome comments from readers who have tried the CogniFit product.

Wednesday, December 05, 2012

New Love, a short shelf life...

Lyubomirsky previews her forthcoming book “The Myths of Happiness: What Should Make You Happy, but Doesn’t, What Shouldn’t Make You Happy, but Does.” A few clips:

American and European researchers tracked 1,761 people who got married and stayed married over the course of 15 years. The findings from this and other similar studies have been clear: newlyweds enjoy a big happiness boost that lasts, on average, for just two years…then they are back where they started…new love seems nearly as vulnerable to hedonic adaptation as a new job, a new home, a new coat and other novel sources of pleasure and well-being. (Though the thrill of a new material acquisition generally fades faster.)
Sexual passion and arousal are particularly prone to hedonic adaptation…both men and women are less aroused after they have repeatedly viewed the same erotic pictures or engaged in similar sexual fantasies. Familiarity may or may not breed contempt; but research suggests that it breeds indifference … There are evolutionary, physiological and practical reasons passionate love is unlikely to endure for long. If we obsessed, endlessly, about our partners and had sex with them multiple times a day — every day — we would not be very productive at work or attentive to our children, our friends or our health…Indeed, the condition of being in love has a lot in common with the state of addiction and narcissism; if unabated, it will eventually exact a toll.
WHY, then, is the natural shift from passionate to companionate love often such a letdown? Because, although we may not realize it, we are biologically hard-wired to crave variety. Variety and novelty affect the brain in much the same way that drugs do — that is, they trigger activity that involves the neurotransmitter dopamine, as do pharmacological highs...Evolutionary biologists believe that sexual variety is adaptive, and that it evolved to prevent incest and inbreeding in ancestral environments. The idea is that when our spouse becomes as familiar to us as a sibling — when we’ve become family — we cease to be sexually attracted to each other.

Tuesday, December 04, 2012

Honesty requires time (and lack of justifications)

Here is a nice little piece from Eldar and Bereby-Meyer:

Recent research suggests that refraining from cheating in tempting situations requires self-control, which indicates that serving self-interest is an automatic tendency. However, evidence also suggests that people cheat to the extent that they can justify their unethical behavior to themselves. To merge these different lines of research, we adopted a dual-system approach that distinguished between the intuitive and deliberative cognitive systems. We suggest that for people to restrict their dishonest behavior, they need to have enough time and no justifications for self-serving unethical behavior. We employed an anonymous die-under-cup task in which participants privately rolled a die and reported the outcome to determine their pay. We manipulated the time available for participants to report their outcome (short vs. ample). The results of two experiments support our prediction, revealing that the dark side of people’s automatic self-serving tendency may be overcome when time to decide is ample and private justifications for dishonesty are not available.

Monday, December 03, 2012

Brain regions that predict and regulate risk-taking.

Two recent pieces of work raise the prospect of being able to predict and even regulate a person's risk-taking behavior, by first observing activity of the anterior cingulate cortex and then dialing it up or down.

First, Rudorf et al. show that behavioral risk preferences are reflected in the passive evaluation of risky situations:

"Individual risk preferences have a large influence on decisions, such as financial investments, career and health choices, or gambling. Decision making under risk has been studied both behaviorally and on a neural level. It remains unclear, however, how risk attitudes are encoded and integrated with choice. Here, we investigate how risk preferences are reflected in neural regions known to process risk. We collected functional magnetic resonance images of 56 human subjects during a gambling task (Preuschoff et al., 2006). Subjects were grouped into risk averters and risk seekers according to the risk preferences they revealed in a separate lottery task. We found that during the anticipation of high-risk gambles, risk averters show stronger responses in ventral striatum and anterior insula compared to risk seekers. In addition, risk prediction error signals in anterior insula, inferior frontal gyrus, and anterior cingulate indicate that risk averters do not dissociate properly between gambles that are more or less risky than expected. We suggest this may result in a general overestimation of prospective risk and lead to risk avoidance behavior. This is the first study to show that behavioral risk preferences are reflected in the passive evaluation of risky situations. The results have implications on public policies in the financial and health domain."
Figure: Anticipation risk coding. Neural activation in bilateral ventral striatum (vStr; top) and anterior insula (aIns; bottom) during anticipation of the second card that correlates with anticipation risk, i.e., expected outcome variance.
Second, Ishii et al. show (in mice) that inactivating anterior insular cortex suppresses risk-taking behavior:
"We often have to make risky decisions between alternatives with outcomes that can be better or worse than the outcomes of safer alternatives. Although previous studies have implicated various brain regions in risky decision making, it remains unknown which regions are crucial for balancing whether to take a risk or play it safe. Here, we focused on the anterior insular cortex (AIC), the causal involvement of which in risky decision making is still unclear, although human imaging studies have reported AIC activation in various gambling tasks. We investigated the effects of temporarily inactivating the AIC on rats' risk preference in two types of gambling tasks, one in which risk arose in reward amount and one in which it arose in reward delay. As a control within the same subjects, we inactivated the adjacent orbitofrontal cortex (OFC), which is well known to affect risk preference. In both gambling tasks, AIC inactivation decreased risk preference whereas OFC inactivation increased it. In risk-free control situations, AIC and OFC inactivations did not affect decision making. These results suggest that the AIC is causally involved in risky decision making and promotes risk taking. The AIC and OFC may be crucial for the opposing motives of whether to take a risk or avoid it."