Personality dominance: reflection in brain imaging and spatial attention

Here are two different takes, from the Journals Neuron and Psychological Science on correlates of human dominance hierarchies:
In the Neuron article, Zink et al. monitor the brain activity patters of gamers that form in response to status cues. They set artificial hierarchies by assigning 72 volunteers a skill rank in a computer game that flagged onscreen opponents as superior or inferior players. But the opponents were really computers, and the games and ranks were rigged so that status was only perceived. One finding was that brain regions associated with emotion or pain become busier when gamers are losing to inferior opponents. From their abstract:

....In both stable and unstable social hierarchies, viewing a superior individual differentially engaged perceptual-attentional, saliency, and cognitive systems, notably dorsolateral prefrontal cortex. In the unstable hierarchy setting, additional regions related to emotional processing (amygdala), social cognition (medial prefrontal cortex), and behavioral readiness were recruited...social hierarchical consequences of performance were neurally dissociable and of comparable salience to monetary reward, providing a neural basis for the high motivational value of status...results identify neural mechanisms that may mediate the enormous influence of social status on human behavior and health.

The article in Psychological Science deals with our tendency to represent dominance in vertical terms. This tendency is apparent in linguistic metaphor, anthropological data, sociological data, and scientific theories of personality dominance. The ubiquity of such mappings is consistent with the central postulate of the metaphor-representation perspective: that people must draw from the perceptual domain, as reflected in common metaphors, when attempting to represent abstract concepts such as dominance or power. Moeller et al. examine whether dominant personality correlates with performance on vertical versus horizontal discriminations.

Previous research has shown that dominant individuals frequently think in terms of dominance hierarchies, which typically invoke vertical metaphor (e.g., "upper" vs. "lower" class). Accordingly, we predicted that in spatial attention paradigms, such individuals would systematically favor the vertical dimension of space more than individuals low in dominance. This prediction was supported by two studies (total N = 96), which provided three tests involving two different spatial attention paradigms. In all cases, analyses controlling for speed of response to horizontal spatial probes revealed that more dominant individuals were faster than less dominant individuals to respond to probes along the vertical dimension of space. Such data support the metaphor-representation perspective, according to which people think in metaphoric terms, even in on-line processing tasks. These results have implications for understanding dominance and also indicate that conceptual metaphor is relevant to understanding the cognitive-processing basis of personality.

Our brains can choose our actions 10 sec before awareness

Here is an elegant update from Soon et al. of the continuing story that started with Libet's original observation that supplementary motor area (SMA) becomes active before our subjective sense of consciously willing an action. This work ignited a a long controversy as to whether subjectively 'free' decisions are determined by brain activity ahead of time. These new results go substantially further than those of previous studies by showing that the earliest predictive information is encoded in specific regions of frontopolar and parietal cortex, up to 10 seconds before it enters awareness (and not in SMA), presumably reflecting the operation of a network of high-level control areas that begin to prepare an upcoming decision. This preparatory time period in high-level control regions is considerably longer than that reported previously for motor-related brain regions.


Figure (click to enlarge) Color-coded brain areas show regions where the specific outcome of a motor decision could be decoded before (bottom, green) and after (top, red) it had been made. The graphs separately depict for each time point the accuracy with which the subject's free choice to press the left or right button could be decoded from the spatial pattern of brain activity in that region (solid line, left axis; filled symbols, significant at P < 0.05; open symbols, not significant; error bars, s.e.m.; chance level is 50%). As might be expected, the decoding accuracy was higher in cortical areas involved in the motor execution of the response than in areas shaping the upcoming decision before it reaches awareness (note the difference in scale). The vertical red line shows the earliest time at which the subjects became aware of their choices. The dashed (right) vertical line in each graph shows the onset of the next trial. The inset in the bottom left shows the representative spatial pattern of preference of the most discriminative searchlight position in frontopolar cortex for one subject (ant, anterior; sup, superior)

Brain exercises

A few moments with google, using search items like "brain exercises" will immediately bring you to a large number of web sites that offer to improve your mental function, combat the decay of mental performance with aging, etc. Some of these have appeared since my previous posting which listed several. A recent NYTimes article (from which the graphic on the left is taken) points to a number of these sites and offers an interesting discussion.

I have held back from taking the plunge into brain exercises, partly because I'm afraid of what I might find find out about how far gone I already am, and partly because some which appear to be most thoroughly researched and academically respectable want your money. But, now happy-neuron.com has offered me a free login to try out their regime, and so I have taken the bait. I will be offering my opinion of this site after immersing in their 20 min exercise sessions for a few weeks, and if I have the stamina or remaining self-esteem (and get offered a free login), will review some of the other sites in subsequent posts.

The Posterior–Anterior Shift in Aging

Here is some more interesting information on brain changes with aging (material I almost don't want to know about, knowing that I'm surely well along with the 'compensations for neural decline' being described.... ):

Older adults reallocate neural resources, increasing activity in prefrontal cortex to perform cognitive tasks, presumably to compensate for declining neural processing in posterior brain regions. Davis et al. show: 1). that this reflects the effects of aging rather than differences in task difficulty (i.e. not due to the same cognitive tasks tending to be more demanding for older adults than for younger adults); 2). that the shift in fact reflects compensation (the age-related increase in PFC activation is positively correlated with cognitive performance and negatively correlated with the age-related decrease in occipitotemporal activity.); and 3). that the deactivation of the midline "default network" associated with conscious rest processes, which must be suppressed for successful cognitive performance, is reduced in posterior midline cortex but increased in medial frontal cortex.

The experiments were performed on 12 younger (mean age = 22.2 years) and 12 older adults (mean age = 69.2 years), presumably referenced by the Y and O prefixes in this figure from the paper (I'm not clear from the text on what distinguishes YM and YP, but I think they refer to the two different tasks, episodic retrieval and visual discrimination).

Figure (click to enlarge) - The posterio-anterior shift pattern for activations: across 2 different tasks and 2 levels of confidence, the occipital cortex showed greater activity in younger than in older adults A, whereas PFC showed the opposite pattern (B). The PASA pattern for deactivations: across 2 different tasks and 2 levels of confidence, posterior midline cortex (precuneus, C) showed greater deactivations in younger than older adults, whereas the anterior midline cortex (medial PFC, D) showed the opposite pattern. Notes: Activation bars represent effect size for each modeled effect, and error bars represent standard error for peak activity across participants.

At Deric and MindBlog's home...

Spring around the 1860 stone schoolhouse on Twin Valley Rd. in Middleton WI. is taking its time. It was a very hard winter.

Despair, Inc.

Out of good 'ol Austin Texas (the original slacker capital), this foil to today's first post (see below), a great site of demotivational materials - just the antidote one needs to the happiness and corporate motivation industry. Check out the lithographs and also the article by Rob Walker.

Above, the "this glass is now half empty" cup; below right, the "GIVE UP" lithograph: "At some point, hanging in there just makes you look like an even bigger loser."

Happiness is...

...having what you want, wanting what you have, or both? In Rabbi Hyman Schachtel's 1954 book on "The real enjoyment of living" he proposed that "happiness is not having what you want, but wanting what you have." To test this idea Larsen and McKibban subject psychology undergraduates at Texas Tech Univ. in Lubbock, TX. to experiments in which they generate lists of "items that you have in your life, as well as items that you want." Both variables accounted for unique variance in happiness. (The students also completed several different standard subjective happiness questionaires.)


As suggested by Schachtel's maxim, participants who wanted what they had more than others did tended to be happier, r = .36, prep > .99 (see Figure, left panel). In addition, however, those who had more of what they wanted tended to be happier, r = .41, prep > .99 (Figure, right panel), as did those who simply had more things, r = .25, prep = .97. In contrast, the extent to which people simply wanted things was uncorrelated with happiness, r = .11.3

An integrated view of our subjective energies.

I recently attended the Wisconsin Symposium on Emotion (Now in its 14th year). Its topic was "Emotion, Consciousness and Psychopathology." I want to mention the talk given by A.D.(Bud) Craig, which was a real tour de force, the kind of science I feel I can integrate with my own personal experience. Its title was "How do you feel? The neurobiological basis for human awareness of feelings from the body." I have referenced Craig's work in previous posts, also check here. Here are PDFs of his two recent review articles in Trends in Cognitive Science (2005) and Nature Reviews Neuroscience (2002) which I recommend.

His view is that in our nervous systems, there is a fundamental bilateral partitioning or separation, from basic spinal cord and brain stem homeostatic systems to our highest prefrontal lobe functions, in which the right side spends energy and the left side brings it in. This reflects the relative activities of the sympathetic versus parasympathetic nervous systems. (enter 'parasympathetic' in the google search box in the left column to see some previous mindblog posts on autonomic regulation of chilling out versus getting excited).

The right and left insula appear to be central in processing feelings, all the way from basic (interoceptive) body sensing (posterior insula) up through subjective feelings, disgust, trust, anger, social hurt, empathic happiness, lust, pain, etc. All of these are homeostatic emotional currency that help regular body balance all the way from from blood pressure, glucose, heart rate, salt regulation, up through social self image. Here is a graphic from his 2005 article that shows the central role of the left and right anterior insula (which act as the sensory cortex of limbic system) in receiving information about body state and feeling from sympathetic and parasympathetic input and then interacting with anterior cingulate (the motor cortex of the limbic system) and frontal cortex. (click to enlarge):


Positive emotions (pleasant music, maternal emotions) correlate with enhanced left parasympathic, left anterior insula, left anterior cingulate and left frontal activation, while negative emotions (anger, fear, etc.) enhance activation of the corresponding structures on the right side.

Some very simple manipulations can stroke the relative activation of these two systems. Slowing one's breathing, as usually happens during meditation dials up the left anterior insula system, while breathing more rapidly increases anxiety and right anterior insula activity. In fact, giving instruction to a subject to breathe more slowly or more rapidly can change their emotional reaction to stimuli. In one experiment mentioned by Craig, a picture of a baby seal elicited warm nuturing emotions when breathing was slowed, but when breathing was increased, subjects were more likely to suspect the seal might attack or bite them! Experiments are now being attempted to measure whether oxytocin (the affiliative, trusting hormone) correlate with left insular activation while right insula activation correlates with cortisone (the stress hormone) release.

This sort of global description fascinates me, because it instructs us in how integrated a package we are, and how attention to some of the basement details of our daily life (such as breathing) can fundamentally alter our mood and temperament.

Attention regulation in meditation

From the Laboratory of Affective Neuroscience at the Univ. of Wisc. in Madison, Lutz, Davidson and collegues offer a review in Trends in Cognitive Science (PDF here) of studies of the effects on attention and emotion processes of two broad categories of meditation: focused attention and open monitoring.

Enhance your working intelligence with simple exercises...

Bakalar points to an interesting study by Jaeggi et al. showing that fluid intelligence (the kind of mental ability that allows us to solve new problems without having any relevant previous experience) can be enhanced by simple working memory training. It turns out that carefully structured training of the kind of memory that allows memorization of a telephone number just long enough to dial it enhances performance on standard tests of fluid intelligence. This suggests that fluid intelligence and working memory depend on the same brain circuitry.

Fairness activates brain reward circuitry.

Some interesting observations from Tabibnia et al. They:

...examined self-reported happiness and neural responses to fair and unfair offers while controlling for monetary payoff. Compared with unfair offers of equal monetary value, fair offers led to higher happiness ratings and activation in several reward regions of the brain. Furthermore, the tendency to accept unfair proposals was associated with increased activity in right ventrolateral prefrontal cortex, a region involved in emotion regulation, and with decreased activity in the anterior insula, which has been implicated in negative affect. This work provides evidence that fairness is hedonically valued and that tolerating unfair treatment for material gain involves a pattern of activation resembling suppression of negative affect.

Figure legend - Ventromedial prefrontal cortex (VMPFC), ventral striatum, and amygdala activation associated with fairness preference. The illustration (a) shows the location of clusters with significantly greater activation in response to fair compared with unfair offers.



Figure legend - Brain activation associated with the tendency to accept unfair offers. The illustrations show the location of areas in (a) left anterior insula and (c) right ventrolateral prefrontal cortex (right VLPFC) whose activation predicted this tendency.

More on language and perception...

Christine Kenneally writes a nice summary of current work on how language can nudge our perception. One interesting result demonstrates that labeling different categories enhances one's ability to discriminate between them. She discusses the work of Boroditsky mentioned in my Feb. 22 post, and work showing that in giving us symbols for spatial patterns, spatial language helps us carve up the world in specific ways. It appears that the ability to count is necessary to deal with large, specific numbers. And the only way to count past a certain point is with language.

The secret life of emotions.

Another demonstration that we can be nudged by unconscious emotional stimuli - that both global and specific emotional responses can be induced without awareness. From the discussion of an article with the title of this post from Ruys and Stapel, whose results show:

...that specific emotions can be elicited without conscious awareness of their cause...disgusting pictures (presented for 120 msec, not perceived) increased cognitive accessibility of disgust words and feelings of disgust. Similarly, fearful pictures increased cognitive accessibility of fear words and feelings of fear. When exposure to the priming stimuli was super-quick (40 msec), global mood, rather than a specific emotion, was evoked. These findings... empirically demonstrate (a) that specific emotions can be evoked without conscious awareness of their cause, (b) that unconscious exposure to emotion-eliciting pictures can evoke the specific corresponding emotion and does not evoke other emotions of similar valence, and (c) that unconscious emotion induction develops from elicitation of global affect to elicitation of specific emotions.

For a calm start to your week... some Debussy

Here is a second version (posted April 23, 2007) of the Debussy Reverie I initially put on YouTube Aug 29, 2006). I'm amazed that the first version has had ~90,000 viewings, and the second (made in response to comments on the first version) has had ~8,000.

A longevity-o-meter

Check out the "Vitality Compass" at the Blue Zones Community website. The results of a 2-3 minute quiz are based on a complex, 106-page algorithm developed by Dr. Robert Kane, a physician and a professor at the University of Minnesota School of Public Health. Here is my result (I'm 66 years old). Blue zone years refer to the number of years one has gained or lost given one's current behaviors.:

If you haven't OD'ed on the internet already....

Have a look at this site, which points to "20 websites that can change your life." (with 2 more added by feedback from viewers). Engaging a number of them (especially twitter) would appear to destroy any remnants of time or privacy that your life might contain.

Brain network disruption during aging.

Most work on brain changes with aging has focused on individual regions, especially those in the frontal lobe, which may shrink or lose activity even in the absence of disease. Andrews-Hanna et al. offer an important paper showing how long range interactions between brain regions are compromised with aging. The work looked at neural activity during a task in two large-scale networks that span the brain: the default network, used when we’re worrying, thinking of the past and future, or imagining people in our lives; and the attention network, used when we’re focusing on a specific task, such as word processing or math problems. The brain regions making up these systems were in sync in young people, but much less so, or not at all, in people over 60.

Figure - the younger brain, below, shows more synchronized activity than the older brain, above.

Brain imaging can predict the mistakes you are about to make.

From Fountain's review of work by Eichele et al.:

...brain patterns start to change about 30 seconds before an error is committed... changes were seen in two brain networks. One, called the default mode region, is normally active when a person is relaxed and at rest. When a person is doing something, like playing the game, this region becomes deactivated...researchers found that in the time leading up to an error, the region became active again — the subject was heading toward a relaxed state...Another network in the right frontal lobe gradually became less active, the researchers found. This is an area in the brain thought to be related to cognitive control, Dr. Eichele said, to keeping “on task.”

...it might be possible someday to develop a warning system — perhaps by monitoring the brain’s electrical activity, which is more practical — that could be used by people doing monotonous or repetitive tasks. Such a system would alert users when they are heading for a harmful or costly, not to mention mindless, mistake.

Positive psychology - a new organization

Some of you might wish to check out the website of the new International Positive Psychology Association (IPPA). It's board includes Martin Seligman, Mihaly Csikszentmihalyi, Tal Ben-Shahar, etc. The organization seeks to promote the science and practice of positive psychology and to facilitate communication and collaboration among researchers and practitioners around the world. A first world congress is planned for June 2009 in Philadelphia.

An antidepressant enhances brain plasticity

The title of the article by Vetencourt et al. is "The Antidepressant Fluoxetine Restores Plasticity in the Adult Visual Cortex. " [Fluoxetine hydrochloride, i.e. Prozac, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class.] Here is their abstract:

We investigated whether fluoxetine, a widely prescribed medication for treatment of depression, restores neuronal plasticity in the adult visual system of the rat. We found that chronic administration of fluoxetine reinstates ocular dominance plasticity in adulthood and promotes the recovery of visual functions in adult amblyopic animals, as tested electrophysiologically and behaviorally. These effects were accompanied by reduced intracortical inhibition and increased expression of brain-derived neurotrophic factor in the visual cortex. Cortical administration of diazepam prevented the effects induced by fluoxetine, indicating that the reduction of intracortical inhibition promotes visual cortical plasticity in the adult. Our results suggest a potential clinical application for fluoxetine in amblyopia as well as new mechanisms for the therapeutic effects of antidepressants and for the pathophysiology of mood disorders.