MRI - the new phrenology

Having just done a posting on MRI, I thought it appropriate to point to a discussion by Michael Shermer in his "Skeptic" column in the Scientific American on the misuse and over-interpretation of MRI data.

It is a reminder that seeing scans with highlighted (usually in red) areas where your brain “lights up” when thinking about X (money, sex, God, and so on) should not seduce us into buying the Swiss Army knife model of the brain, with specialized modules for vision, language, facial recognition, cheating detection, risk taking, spirituality and even God. There is the minor problem of reversing the causal inference:

...where people see some activity in a brain area and then conclude that this part of the brain is where X happens. We can show that if I put you into a state of fear, your amygdala lights up, but that doesn’t mean that every time your amygdala lights up you are experiencing fear. Every brain area lights up under lots of different states. We just don’t have the data to tell us how selectively active an area is.

As Patricia Churchland points out:

Mental modules are complete nonsense. There are no modules that are encapsulated and just send information into a central processor. There are areas of specialization, yes, and networks maybe, but these are not always dedicated to a particular task.” Instead of mental module metaphors, let us use neural networks.

The MRI of morality?

Greg Miller reviews research on the nature of human morality which continues to probe the debate between the views of of David Hume - that emotions drive moral judgments - and Immanuel Kant - who argued that reason should be the driving force. He includes reference to a recent study by Hsu, Anen, and Quartz on equity and efficiency. Some clips, from from the Miller review, and then the Hsu et al paper:

One research group:

...asked dozens of college students to consider several morally charged situations. In one, a friend lies on his résumé to land a job; in another, survivors of a plane crash consider cannibalizing an injured boy to avoid starvation. Students who pondered these hypothetical scenarios while sitting at a filthy desk with sticky stains and a chewed-up pen rated them as more immoral than did students who sat at a pristine desk. In another version of the experiment, a nearby trash can doused with novelty fart spray had a similar effect. The findings...demonstrate that emotions such as disgust exert a powerful influence on moral judgments, even when they are triggered by something unrelated to the moral issue.

Hsu et al. consider distributive justice, illustrated by the following example:

Imagine driving a truck with 100 kg of food to a famine stricken region. The time it would take you to deliver food to everyone would cause 20 kg of food to spoil. If you delivered food to only half the population you would lose only 5 kg. Do you deliver the food to only half the population to maximize the total amount of food, or do you sacrifice 15 kg to help everyone and achieve a more equitable distribution?

They examine the the tradeoff between equity and efficiency, finding:

...that the putamen responds to efficiency, whereas the insula encodes inequity, and the caudate/septal subgenual region encodes a unified measure of efficiency and inequity (utility). Strikingly, individual differences in inequity aversion correlate with activity in inequity and utility regions. Against utilitarianism, our results support the deontological intuition that a sense of fairness is fundamental to distributive justice, but, as suggested by moral sentimentalists, is rooted in emotional processing. More generally, emotional responses related to norm violations may underlie individual differences in equity
considerations and adherence to ethical rules.

Neuroimaging studies have linked several brain regions to moral cognition. Disruptions to the right temporoparietal junction (brown), which is involved in understanding intentions, or the ventromedial prefrontal cortex (green), which processes emotion, have been found to alter moral judgments... activity in the anterior cingulate cortex (pink) may signal conflict between emotion, reflected by activity in the medial frontal gyrus (blue) and other areas (orange, brown), and "cold" cognition, reflected by activity in dorsolateral prefrontal cortex (yellow).

Some Chopin to start the week...

I'm warming up to do some recordings this spring and summer.... this is Chopin's Nocture Op. 9 No. 1

Lacking power diminishes cognitive function

An implication of meritocracies is that individuals who lack power are low achievers because they are less capable or less motivated than those who acquire power. Smith et al. propose, alternatively, that powerless people often achieve less than powerful people because lacking power itself fundamentally alters cognitive functioning and increases vulnerability to performance decrements during complex executive tasks.

In a experiment carried out on 101 Dutch university students, simply assigning each participant to be either a superior or a subordinate in a computer-based task altered their performance on tests of executive function. (Participants were told that the superior would direct and evaluate the subordinate. This evaluation would purportedly determine the subordinate's payment for the experiment, whereas the superior would be paid a fixed amount.) Smith et al. found that the powerless were less effective than the powerful at standard tests evaluating ability to update, inhibition, and planning. Because existing research suggests that the powerless have difficulty distinguishing between what is goal relevant and what is goal irrelevant in the environment, a further experiment was carried out to establish that the executive-function impairment associated with low power is driven by goal neglect.

This work consistent with the idea that the cognitive alterations arising from powerlessness may help foster stable social hierarchies. The results also have implications for management and organizations. In many industries (e.g., health care, electric power), errors can be costly. Increasing employees' sense of power could lead to improved executive functioning, decreasing the likelihood of catastrophic errors.

Rapid orienting to positive, as well as negative, emotional stimuli.

Most of the work on how emotions focus our attention has focused on negative stimuli (snakes, angry faces, etc.) Brosch et al. use ERP measurement to note that our attention also can very reliably be captured by positive nurturance stimuli such as baby faces. The results confirm that biological relevance, and not exclusively fear, produces an automatic spatial orienting toward the location of a stimulus. From the paper:

...we recorded event-related potentials from 20 subjects performing a dot-probe task in which the cues were fear-inducing and nurturance-inducing stimuli (i.e., anger faces and baby faces). Highly similar validity modulation was found for the P1 time-locked to target onset, indicating early attentional capture by both positive and negative emotional stimuli. Topographic segmentation analysis and source localization indicate that the same amplification process is involved whether attention orienting is triggered by negative, fear-relevant stimuli or positive, nurturance-relevant stimuli.

Illustration of the experimental sequence. Each trial started with a fixation cross. Then the cue, consisting of two images presented on the left and right sides of the screen, was presented briefly. One of the two pictures was an emotional face, and the other was a neutral face. Following offset of the face pair, the fixation cross was presented randomly for 100, 150, 200, 250, or 300 ms. Afterward, the target, a triangle pointing upward or downward, appeared for 150 ms in the location of one of the previously presented faces. In a valid trial, the triangle was in the location of the emotional image; in an invalid trial, the triangle was in the location of the neutral image. Some participants were required to respond if the triangle pointed upward, and the others were required to respond if the stimulus pointed downward. SOA = stimulus onset asynchrony.

Our facial touch sensitivity - enhanced by viewing a touch.

Studies have shown that observing touch on another person's body activates brain regions involved in tactile perception, even when the observer's body is not directly stimulated. Previous work has shown that in some synaesthetes, this effect induces a sensation of being touched. Serino et al. show in nonsynaesthetes, that

..when observers see a face being touched by hands, rather than a face being merely approached by hands, their detection of subthreshold tactile stimuli on their own faces is enhanced. This effect is specific to observing touch on a body part, and is not found for touch on a nonbodily stimulus, namely, a picture of a house...Thus, observing touch can activate the tactile system, and if perceptual thresholds are manipulated, such activation can result in a behavioral effect in nonsynaesthetes.The effect is maximum if the observed body matches the observer's body.

Figure - Visual stimuli used in the tactile confrontation task. In blocked trials, subjects viewed an image of their own face, another person's face, or a house. In each trial, the finger on the bottom left, the finger on the bottom right, or both fingers moved toward the target; in the touch condition, the finger (or fingers) actually touched the target, and in the no-touch condition, the finger (or fingers) reached a position 5 cm away from the target.

Think of when you might have watched a romantic touch in a movie, sitting next to someone you wished would stroke you.....

Brain monoamine oxidase activity predicts male aggression

Here is an edited version of the abstract from Alia-Klein et al.:

The genetic deletion of monoamine oxidase A (MAO A), an enzyme that breaks down the monoamine neurotransmitters norepinephrine, serotonin, and dopamine, produces aggressive phenotypes across species. In humans, studies provide evidence linking the MAOA genotypes and violent behavior but only through interaction with severe environmental stressors during childhood. The authors asked whether in healthy adult males the gene product of MAO A in the brain, rather than the gene per se, would be associated with regulating the concentration of brain amines involved in trait aggression. They measured brain MAO A activity was measured in vivo in healthy nonsmoking men with positron emission tomography using a radioligand specific for MAO A. Trait aggression was measured with the multidimensional personality questionnaire (MPQ). They show for the first time that brain MAO A correlates inversely with the MPQ trait measure of aggression (but not with other personality traits)...the lower the MAO A activity in cortical and subcortical brain regions, the higher the self-reported aggression (in both high and low MAO A genotype groups) contributing to more than one-third of the variability. Trait aggression is a measure used to predict antisocial behavior, and thus these results underscore the relevance of MAO A as a neurochemical substrate of aberrant aggression.

The Neural Buddhists

Check out the David Brooks OpEd piece with the title of this post. You really have to respect Brooks for putting so much energy into understanding contemporary mind science.

...the self is not a fixed entity but a dynamic process of relationships. Second, underneath the patina of different religions, people around the world have common moral intuitions. Third, people are equipped to experience the sacred, to have moments of elevated experience when they transcend boundaries and overflow with love. Fourth, God can best be conceived as the nature one experiences at those moments, the unknowable total of all there is...In their arguments with Christopher Hitchens and Richard Dawkins, the faithful have been defending the existence of God. That was the easy debate. The real challenge is going to come from people who feel the existence of the sacred, but who think that particular religions are just cultural artifacts built on top of universal human traits. It’s going to come from scientists whose beliefs overlap a bit with Buddhism...In unexpected ways, science and mysticism are joining hands and reinforcing each other. That’s bound to lead to new movements that emphasize self-transcendence but put little stock in divine law or revelation. Orthodox believers are going to have to defend particular doctrines and particular biblical teachings. They’re going to have to defend the idea of a personal God, and explain why specific theologies are true guides for behavior day to day. I’m not qualified to take sides, believe me. I’m just trying to anticipate which way the debate is headed. We’re in the middle of a scientific revolution. It’s going to have big cultural effects.

Your sexy voice and your hormones.

I'm passing this on to you, despite the fact that this gem went straight from the NY Times to the maw of the John Stuart Daily News/Colbert Report machine within one day... a women's voice becomes more seductive during ovulation, possibly because the larynx changes both its shape and size in response to reproductive hormones.

...The researchers recorded voice samples from about 50 undergraduate women at four times in their menstrual cycle. Then they asked 34 men and 32 women to listen to the recordings and rate them in terms of attractiveness...On the surface, the recordings were not terribly sexy. The women were asked to count from 1 to 10. But they must have been doing something different when they were closest to ovulating, because that was when they received the highest ratings, the researchers said.

So, I wonder if something similar happens in guys who are juiced when their testosterone levels increase?

Your lips in my brain...

The title of the Kriegstein et al. article is: "Simulation of talking faces in the human brain improves auditory speech recognition." It turns out that observing a specific person talking for 2 min improves our subsequent auditory-only speech and speaker recognition for this person. This shows that, in auditory-only speech, the brain exploits previously encoded audiovisual correlations to optimize communication. The authors suggest that this optimization is based on speaker-specific audiovisual internal models, which are used to simulate a talking face. From the author's introduction:

Human face-to-face communication works best when one can watch the speaker's face. This becomes obvious when someone speaks to us in a noisy environment, in which the auditory speech signal is degraded. Visual cues place constraints on what our brain expects to perceive in the auditory channel. These visual constraints improve the recognition rate for audiovisual speech, compared with auditory speech alone. Similarly, speaker identity recognition by voice can be improved by concurrent visual information. Accordingly, audiovisual models of human voice and face perception posit that there are interactions between auditory and visual processing streams

Neurophysiological face processing studies indicate that distinct brain areas are specialized for processing time-varying information [facial movements, superior temporal sulcus (STS), and time-constant information (face identity, fusiform face area (FFA). If speech and speaker recognition are neuroanatomically dissociable, and the improvement by audiovisual learning uses learned dependencies between audition and vision, the STS should underpin the improvement in speech recognition in both controls and prosopagnosics. A similar improvement in speaker recognition should be based on the FFA in controls but not prosopagnosics. Such a neuroanatomical dissociation would imply that visual face processing areas are instrumental for improved auditory-only recognition.

The authors in fact obtained these results when they used functional magnetic resonance imaging (fMRI) to show the response properties of these two areas.

Want to chill out? Exaggerate you abilities.

An interesting article by Gramzow et al. in the Feburary issue of Emotion finds that exaggeration (such as students inflating their grade-point average) doesn't induce the anxiety that usually goes with lying or keeping secrets. Some clips from Benedict Carey's discussion of the article:

...embroiderers often work to live up to the enhanced self-images they project. The findings imply that some kinds of deception are aimed more at the deceiver than at the audience, and they may help in distinguishing braggarts and posers from those who are expressing personal aspirations, however clumsily...The researchers pulled the students’ records, with permission, and found that almost half had exaggerated their average by as much as six-tenths of a point. Yet the electrode readings showed that oddly enough, the exaggerators became significantly more relaxed while discussing their grades...It was a robust effect, the sort of readings you see when people are engaged in a positive social encounter, or when they’re meditating...The ones who exaggerated the most appeared the most calm and confident.

Here is the Gramzow et al. abstract:

Students who exaggerate their current grade point averages (GPAs) report positive emotional and motivational orientations toward academics. It is conceivable, however, that these self-reports mask underlying anxieties. The current study examined cardiovascular reactivity during an academic interview in order to determine whether exaggerators respond with a pattern suggestive of anxiety or, alternatively, equanimity. Sixty-two undergraduates were interviewed about their academic performance. Participants evidenced increased sympathetic activation (indexed with preejection period) during the interview, suggesting active task engagement. Academic exaggeration predicted parasympathetic coactivation (increased respiratory sinus arrhythmia). Observer ratings indicated that academic exaggeration was coordinated with a composed demeanor during the interview. Together, these patterns suggest that academic exaggeration is associated with emotional equanimity, rather than anxiety. The capacity for adaptive emotion regulation--to keep a cool head when focusing on academic performance--offers one explanation for why exaggerators also tend to improve academically. These findings have implications for the broader literature on self-evaluation, emotion, and cardiovascular reactivity.

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.