Friday, May 26, 2006

Cooperation, Punishment, and the Evolution of Human Institutions

This is the title of a review by Henrich of studies on how human cooperations and sanctions might have evolved, which specifically cites a paper by Gurerk et al in Science. People are offered the choice of two institutions in which individuals make voluntary contributions with the total then being equally distributed among all. Participants know what was contributed by others. In the first, individuals who do not contribute still receive an equal share of the total collected but no sanctions are applied to poor contributors. In the second, participants can choose to penalize slackers at some cost to themselves. The authors show "that a sanctioning institution is the undisputed winner in a competition with a sanction-free institution. Despite initial aversion, the entire population migrates successively to the sanctioning institution and strongly cooperates, whereas the sanction-free society becomes fully depopulated. The findings demonstrate the competitive advantage of sanctioning institutions and exemplify the emergence and manifestation of social order driven by institutional selection."

Thursday, May 25, 2006

Stressing out or Chilling out changes how our genes are expressed in an immediate and dynamic way.

Bittman et al., in "Recreational music-making modulates the stress response and alters individual gene expression," have followed the expression of 45 genes associated with stress, immune, and inflammation responses after one hour of a stress induction protocol (solving a 500 piece puzzle while being told at 10 minute intervals that other subjects were doing better). Subjects were then split into three groups for a further hour: one continued the stressful situation, the second read a newspaper, and the third participated in a recreational music making session (the clavinova connection). In the latter group 19 genes expression changes caused by stress were significantly reversed. None were reversed in the group continuing the stress test and 6 reversed in the group just reading a newspaper.

Wednesday, May 24, 2006

The brain finds pleasure in novelty.......

Humans are informavores, and derive pleasure from novel auditory and visual stimulation. Biederman and Vessel note that novel visual images rated most highly by observed also cause stronger activation of the parahippocampal gyrus, where they are interpreted in the context of stored memories, and this activation fades as the same image is repeated and becomes more familiar. This area is also rich in mu-opioid receptors (involved in pleasure and reward, and activated by morphine and endogenous morphine-like substances - endomorphins - in the brain). They suggest that the rate of endomorphin release in the parahippocampal cortex partially underlies our human preference for experiences that are both novel and richly interpretable.




Legend: Visual information flows from the primary visual cortex (bottom, orange) towards parahippocampal regions where it is interpreted (middle, purple). Credit: American Scientist.

Tuesday, May 23, 2006

Religion as a Natural Phenomenon - More on Dennett's Book "Breaking the Spell"

This book has now received extensive and varying reviews in both popular (New York Times Book Review, The New Yorker) and scientific (Science, Nature) magazines. Dennett and others argue that religion appeared because groups of humans that developed religious rituals replicated themselves more successfully than those that did not. The fact that human brains developed both self awareness and awareness that others are aware may have led us to have hyperactive agent detection capabilities that not only protect us, but also lead us to believe that rocks and trees are imbued with intentional minds or spirits. This is animism, which led to polytheism, and eventually monotheism. The values of religion to evolutionary fitness could include (from Shermer's review in Science) mythmaking (to explain the dangers and meaning of the natural world), morality (to regulate pro- and anti-social behavior), sociality (within-group amity and between-group enmity), and redemption and resurrection (forgiveness in this life and immortality in the next life). Dennett points out how US mega-churches cater to people's needs - they have a product that opens the wallets of their members as well as moral and social values "that lead to anti-abortion fanaticism, capital punishment, excoriation of gays and lesbians, and dangerous military excursions in the Near East." (from Ruse's Nature review). The religion "meme" continues to grow in the vast majority of humans alive today. (The term "meme" , coined by Richard Dawkins, refers to thoughts, songs, or rituals that replicate and propagate from one human mind to another. The idea is that memes underlie cultural evolution just as genes underlie biological evolution.)

Monday, May 22, 2006

The pleasures and pains of information about the future.

Berns et al show that regions of the brain activated by pain are also activated by the anticipation of pain, and that some experimental subjects choose to receive an anticipated electrical shock sooner rather than later, to "get it over with," even when told the shock will be larger than the anticipated one.

It is also known that brain regions activated by pleasure are also activated by anticipation of pleasure, and subjects will frequently defer a desired outcome to prolong the pleasure of anticipation. These real behaviors are the exact opposite of those in many economic models, which assume that people will defer negative outcomes and accelerated desired ones.

A review by Loewenstein highlights varied studies on the utility of information, and how emotional factors lead people to desire or avoid it.

Friday, May 19, 2006

Two ways of knowing the minds of others

Mitchell's laboratory at Harvard has shed light on two traditionally opposed hypotheses about how we infer the mental states of others. Simulation theory posits that we use our own experience to infer the experience of others. It is known that when we observe actions and emotions in others, regions in our own brain that would generate those actions or emotions become active and mirror what we are observing. Theory of mind, on the other hand, holds that we use abstract rules about how people behave to infer the mental states of others.

Mitchell et al used functional neuroimaging to examine how perceivers make mental state inferences when such self-other overlap can be assumed (when the other is similar to oneself) and when it cannot (when the other is dissimilar from oneself). "We observed a double dissociation such that mentalizing about a similar other engaged a region of ventral mPFC (medial prefrontal cortex) linked to self-referential thought, whereas mentalizing about a dissimilar other engaged a more dorsal subregion of mPFC. "

Legend: Division of labor. Different regions of prefrontal cortex fire up when people ponder the mental states of others perceived as similar (blue) or dissimilar (red) to themselves. Credit: Jason Mitchell.

"The overlap between judgments of self and similar others suggests the plausibility of "simulation" accounts of social cognition, which posit that perceivers can use knowledge about themselves to infer the mental states of others." And, the activation of dorsal mPFC during thinking about dissimilar others might correspond to more rule bound theory of mind operations.

Thursday, May 18, 2006

The good, the bad and the amygdala

This is the title of a brief review by Ruth Williams in Nature Reviews Neuroscience pointing out an article by Paton et al. that demonstrates that in monkeys the values associated with visual stimuli are represented in the amygdala, a structure involved in reinforcement learning. Individual amygdala neurons apparently code for either "good" or "bad" . When a visual stimulus that was initially paired with a positive reward was switched to being paired with a negative reward, more that half of the responding amygdala neurons showed a switch in activity that correlated with changes in behavior, and some individual neurons showed value-specific activity. This work further confirms that the amygdala is a key brain structure in the representation of the learned value of visual stimuli.

Wednesday, May 17, 2006

Dolphins have discovered "names" of the sort we use.

It has been known since the 1960s that dolphins develop individually distinctive signature whistles that they use to maintain group cohesion. Now Janik et al have shown that dolphins extract identity information from signature whistles even after all voice features have been removed from the signal. The synthesized whistles retained the distinct variation in frequency over time of an individual's signal, but removed other characteristics like harmonics, dynamics, and extraneous noises such as the clicking sounds that dolphins can also make. When exposed to the artificial whistle modeled after that of a related group member, other dolphins turned towards the sound. Excerpts from Henry Fountain's comments on this work in the New York Times: "To draw an analogy to humans, the frequency modulation pattern is the "language," and the dolphins could identify it regardless of the whistle's "voice." And a quote from Janik: "Most other animals appear to rely on the sound of the voice, rather than any coded information, for recognition. But parrots may have similar "signature" calls, which shows that you can do this if you have a huge brain, but you can also do this if you have a small one."

Tuesday, May 16, 2006

Men and Women react differently to sniffing a social hormone - aggressively versus friendly

Thompson et al have found that a peptide influencing social behaviors in numerous species, Arginine vasopressin (AVP), causes different behaviors in men and women when administered intranasally with an inhaler. In men, AVP stimulates agonistic (i.e. combative) facial motor patterns in response to the faces of unfamiliar men and decreases perceptions of the friendliness of those faces. In contrast, in women, AVP stimulates affiliative facial motor patterns in response to the faces of unfamiliar women and increases perceptions of the friendliness of those faces. AVP also affected autonomic responsiveness to threatening faces and increased anxiety, which may underlie which may underlie the peptide's sex-specific effects on social communication by promoting different social strategies in response to stress in the sexes. The authors note; "Because intranasal AVP administration crosses the blood-brain barrier and, at the dose we used, directly affects central processes, whereas peripheral elevations do not, we argue that the effects we observed were likely centrally mediated, either through CSF-signaling mechanisms or by means of diffusion into discrete brain areas. Thus, our results support the hypothesis that central AVP's ability to influence social communication processes, a conserved trait of AVT and AVP in vertebrates, has been retained in humans."

Monday, May 15, 2006

Recursion in vocalization not unique to humans

Several years ago Marc Hauser, Noam Chomsky and Tecumseh Fitch published an influential paper that speculated that recursion, or self embedding, might be the one aspect of language that is clearly unique to humans. Gentner et al have now shown that the European starling can be trained to recognize complex recursive grammars. A review by Marcus suggest that "the abstract computational capacity of language may consist not so much of a single innovation as a novel evolutionary reconfiguration of many.. ancestral cognitive components, genetically rejigged into a new whole. Contemporary research suggests that the human brain contains few if any unique neuronal types, and few if any genes lack a significant ancestral precedent."

Wednesday, May 10, 2006

Stumbling on Happiness

This is the title of a new book by Harvard psychologist Daniel Gilbert. One quote from the N.Y. Times review by Scott Stossel in the May 7 book review section: "When we have an experience..on successive occasions, we quickly begin to adapt to it, and the experience yields less pleasure each time...Psychologists call this habituation, economists call it declining marginal utility, and the rest of us call it marriage."

His basic theme is that humans are very bad at predicting what will make them happy. Things we expect to give us joy make us less happy than we think; and things that we dread make us less unhappy, especially after some time has passed. There is a "psychological immune system" that starts up after big negative events.

From the book: "How do we manage to think of ourselves as great drivers, talented lovers and brilliant chefs when the facts of our lives include a pathetic parade of dented cars, disappointed partners and deflated souffles?...The answer is simple: We cook the facts." What gets us through life is just the right amount of delusion, enough to fool us into feeling relatively good about ourselves. Interestingly, the clinically depressed seem less susceptible to these basic cognitive errors.

Sunday, April 30, 2006

A new brain module for understanding whole words

While it has been known that rapidly comprehending whole words activates an area called the visual word form area (VWFA), the same area is also activated by faces and objects. Gaillard et al have now shown that this area is indispensable for reading whole words, but not faces and objects. In an operation for severe epilespy, they removed a small area near the VWFA. The patient now required 900 milliseconds rather than 600 milliseconds to recognize a three letter word, suggesting a transition from reading the whole word to reading letter by letter.

What is curious is that a task invented only about 6,000 years ago, understanding whole words as entities instead of letter by letter, apparently requires a dedicated brain area. Since this is a very short time for genetic changes that might enable such an area, it seems more likely that this specialzed area forms during language development in each individual as a solution to the problem of rapidly processing written text.

Tuesday, April 25, 2006

The Paomnnehal Pweor Of The Hmuan Mnid

I cluod aulaclty uesdnatnrd waht I was rdgnieg.

Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

Amzanighuh?

Inhibiting Negative Emotions - Opps!, A simple story evaporates

Numerous studies from Davidson's laboratory and others have shown that deliberately suppressing negative affect correlates with increased activity in the prefrontal cortex (and vice versa). The idea has been that the more modern thinking and interpreting prefrontal cortex feeds down to inhibit the amygdala, the center of emotional reactivity in our more primitive mammalian brain. Most of this work was done on college students or younger people. Urry et al now find that older subjects, 62-64 years of age, can suppress negative affect without a corresponding increase in prefrontal activation. In a supplement they offer reasons for the discrepancy. It is very hard to walk away with any kind of clean message now, a situation not helped by the fact that this is one of the most poorly written jargon laden papers I have ever tried to wade through. The senior authors should have paid more attention to what they were putting their name on.

Monday, April 24, 2006

Brain's Reward Pathway Involved in Mood Disorders

A recent Science article by Berton et. al. shows that long lasting fearful and withdrawal behaviors that are induced in mice by bullying and intimidation are enabled by a nerve growth factor (BDNF, brain derived neurotrophic factor) acting in the mesolimbic dopamine reward pathway in the brain. When a genetic trick is used to knock out DBNT production in just this area, mice are no longer intimidated by bullies. Elsewhere in the brain BDNF is associated with an opposite effect, antidepressant actions. The authors point out that the brain's reward system has been slighted in research on emotional disorders, even though the inability to experience rewarding feelings is a hallmark of depression and emotional withdrawal.

Friday, April 21, 2006

The Self-Help Scam

In the May 2006 issue of The Scientific American, Michael Shermer (publisher of Skeptic magazine) argues that the Self-Help and Actualization Movement (SHAM), an $8.5 billion-a-year business, is a scam. He notes the recent book by Steve Salerno, "SHAM: How the Self-Help Movement Made America Helpless (Crown Publishing Group, 2005). There is an eighteen week rule: the most likely customer for a self help book is someone who bought a similar book with the preceeding eighteen months. If the books worked, why would one need further help? A bulletproof shield surrounds SHAM: if your life does not get better, it is your fault, your thoughts were not positive enough. The solution? More of the same self-help. SHAM books market a clever mix of victimization and empowerment. We are all victims of our demonic "inner children" replaying negative tapes. Redemption comes from empowering yourself with the new "life script" offered by the self-help book or by the masters themselves at prices ranging from $500 to $6,000. Unfortunately there is no evidence that any of the SHAM techniques is better than doing something else or even doing nothing (the same problem is faced by virtually all therapies).

Sunday, April 09, 2006

Our inability to cope with what empirical data show us to be true about how our minds work...

I get frustrated when I try to reconcile what I know from empirical data to be true about my self (see the "I-Illusion" essay on this website) with the common sense feeling of agency and responsibility that we are share.

Our commonsense conceptions of ourselves have co-evolved over hundreds of thousands of years, along with their physiological, homeostatic, neuroendocrine, and limbic emotional correlates. This whole complex (us, that is) can be upset by facing what it can come to know to be true about the impersonal physical processes that actually run our show, finding it impossible to integrate its 'illusory' self image.

Here is a clip, and then its more extended context from the piece by Metzinger on edge.org..his response to the question "What is your dangerous idea." He frames it much better than I can. First the clip:

"I think that the irritation and deep sense of resentment surrounding public debates on the freedom of the will actually has nothing much to do with the actual options on the table. It has to do with the perfectly sensible intuition that our presently obvious answer will not only be emotionally disturbing, but ultimately impossible to integrate into our conscious self-models."

Then the more extended quotation:

"For middle-sized objects at 37° like the human brain and the human body, determinism is obviously true. The next state of the physical universe is always determined by the previous state. And given a certain brain-state plus an environment you could never have acted otherwise. A surprisingly large majority of experts in the free-will debate today accept this obvious fact...."

"Yes, you are a physically determined system. But this is not a big problem, because, under certain conditions, we may still continue to say that you are "free": all that matters is that your actions are caused by the right kinds of brain processes and that they originate in you. A physically determined system can well be sensitive to reasons and to rational arguments, to moral considerations, to questions of value and ethics, as long as all of this is appropriately wired into its brain. You can be rational, and you can be moral, as long as your brain is physically determined in the right way. You like this basic idea: physical determinism is compatible with being a free agent. You endorse a materialist philosophy of freedom as well. An intellectually honest person open to empirical data, you simply believe that something along these lines must be true.

Now you try to feel that it is true. You try to consciously experience the fact that at any given moment of your life, you could not have acted otherwise. You try to experience the fact that even your thoughts, however rational and moral, are predetermined — by something unconscious, by something you can not see. And in doing so, you start fooling around with the conscious self-model Mother Nature evolved for you with so much care and precision over millions of years: You are scratching at the user-surface of your own brain, tweaking the mouse-pointer, introspectively trying to penetrate into the operating system, attempting to make the invisible visible. You are challenging the integrity of your phenomenal self by trying to integrate your new beliefs, the neuroscientific image of man, with your most intimate, inner way of experiencing yourself. How does it feel?

I think that the irritation and deep sense of resentment surrounding public debates on the freedom of the will actually has nothing much to do with the actual options on the table. It has to do with the perfectly sensible intuition that our presently obvious answer will not only be emotionally disturbing, but ultimately impossible to integrate into our conscious self-models.

Or our societies: The robust conscious experience of free will also is a social institution, because the attribution of accountability, responsibility, etc. are the decisive building blocks for modern, open societies. And the currently obvious answer might be interpreted by many as having clearly anti-democratic implications: Making a complex society work implies controlling the behavior of millions of people; if individual human beings can control their own behavior to a much lesser degree than we have thought in the past, if bottom-up doesn't work, then it becomes tempting to control it top-down, by the state. And this is the second way in which enlightenment could devour its own children. Yes, free will truly is a dangerous question, but for different reasons than most people think. "

Wednesday, April 05, 2006

Why do I feel an urge to write about how the mind works?

Here are some sentences trying to put together one motivation for doing this website and this mindblog....and for working up a new web essay titled "The Merging of Minds" .. about how our behavior is unconsciously regulated by our social brains and their mirroring systems. If you are reading this (I don't know whether the counter on this web page is monitoring real people or web-bots) I would appreciate any expression of interest or disinterest. (Feedback on this site is very close to zero).

Some sentences of rationale:

Understanding the biological processes that generate our sense of self, our feelings, and our connections to each other reveals engines of our behavior previously hidden from our awareness. Using our awareness to get partial glimpses of those engines in action can loosen their iron grip and let our behaviors be more spontaneous and competent.

I want to cast this material in the form of the lived body understanding it as it plays out in our self observed moment-to-moment behavior, in addition to the more conventional expository writing. This was the point of the self exercises in my "Biology of Mind" book.

Monday, April 03, 2006

Intellectual Ability and Brain Cortex Development in Children

Shaw et. al. have recently published a fascinating study in Nature Magazine that shows that the trajectory of change in the thickness of the cerebral cortex during its development, rather than cortical thickness itself, is most closely related to level of intelligence. Previous studies attempting to correlate thickness or size of frontal cortical regions with intelligence had provided mixed results. Compared to children with average scores, cortex starts out thinner
in children with IQ scores above 120 but later grows thicker. A review of this work by Miller quotes Shaw: "The cortex gets thicker during childhood and reaches a peak and then gets thinner." But the timing of these events was dramatically different in the "superior" group. "the cortex in these children started out thinner, on average, than in the other groups. Then it grew rapidly, starting around age 7, and peaked in thickness around 11 before falling off. Cortical thickness peaked between 7 and 8 years of age in the average-IQ group, and a year or two later in the high-IQ group. By early adulthood, the cortex in all three groups was roughly the same thickness."

Power of Prayer? - apparently not.....

Herbert Benson, author of "The Relaxation Response" and researcher into medical effects of relaxation and prayer has just published, along his coworkers, some long awaited results: "Study of the Therapeutic Effects of Intercessory Prayer (STEP) in cardiac bypass patients: A multicenter randomized trial of uncertainty and certainty of receiving intercessory prayer." (American Heart Journal Volume 151, Issue 4 , April 2006, Pages 934-942). There have been several claims that prayer by strangers could ameliorate the condition of patients at another location (by unknown or supernatural forces...). Over ten studies have been carried out over the past six years with mixed results, but none approached the scientific rigor and number of patients involved in Benson's study.

Not only were there no effects of prayer, but the third of the subjects who were informed that they were being prayed for did slightly worse (performance anxiety?)