Here is another of the rehearsal recordings we make to critique, to be eventually replaced by a final version. It is a run through of the Presto (last movement) of Mozart's Piano Sonata for 4-hands, K. 358. I'm playing base, David Goldberger is playing treble.
Friday, February 26, 2010
Here is another of the rehearsal recordings we make to critique, to be eventually replaced by a final version. It is a run through of the Presto (last movement) of Mozart's Piano Sonata for 4-hands, K. 358. I'm playing base, David Goldberger is playing treble.
Context from the introduction by Lakusta et al.
When rats, human toddlers, or adults are disoriented in a chamber, they search for targets using geometric properties of the layout, often ignoring quite salient nongeometric cues. This pattern has led scientists to hypothesize that reorientation in animals (including humans) is guided by a cognitive module that engages geometric properties of layouts such as the lengths of surfaces, the angles of their intersections, and geometric sense (i.e., “left-” and “right-ness”), but does not engage nongeometric information such as surface color.The authors find that geometric reorientation abilities are specifically impaired in Williams Syndrome patients. (Williams syndrome results from a microdeletion in chromosome 7q11.23. People with the syndrome have mild to moderate retardation and highly selective but severe impairment in a range of spatial tasks that normally engage parietal and other dorsal stream functions of the brain.) Here is their abstract:
The capacity to reorient in one’s environment is a fundamental part of the spatial cognitive systems of both humans and nonhuman species. Abundant literature has shown that human adults and toddlers, rats, chicks, and fish accomplish reorientation through the construction and use of geometric representations of surrounding layouts, including the lengths of surfaces and their intersection. Does the development of this reorientation system rely on specific genes and their action in brain development? We tested reorientation in individuals who have Williams syndrome (WS), a genetic disorder that results in abnormalities of hippocampal and parietal areas of the brain known to be involved in reorientation. We found that in a rectangular chamber devoid of surface feature information, WS individuals do not use the geometry of the chamber to reorient, failing to find a hidden object. The failure among people with WS cannot be explained by more general deficits in visual-spatial working memory, as the same individuals performed at ceiling in a similar task in which they were not disoriented. We also found that performance among people with WS improves in a rectangular chamber with one blue wall, suggesting that some individuals with WS can use the blue wall feature to locate the hidden object. These results show that the geometric system used for reorientation in humans can be selectively damaged by specific genetic and neural abnormalities in humans.
Thursday, February 25, 2010
There is continuing debate over whether, and to what extent, we humans (like other mammals) might use body odors secreted from our skin in signaling sexual attraction, aggression, submission, etc. Several progesterone derivatives have been shown to activate regions of the thalamus and hypothalamus, and the activations are differentiated with respect to sex and sexual orientation of the smeller in relation to the respective compounds. Slavic et al. asked whether compounds actually released by our bodies have pheromone properties, and focused on highly volatile androstenol, which is found (primarily in males), in sweat, urine, plasma and saliva. They found that smelling androstenol (unlike several common odors) causes activation of a portion of the hypothalamus in women that animal data suggests mediates pheromone triggered mating behavior. (The article is open access, and you can see the brain imaging data there.)
Observations from Platek and Singh add to the evolutionary psychologists' discussion of determinants of men's sexual preferences. They take male preference for lower hip waist ratio in females (as indicative of reproductive quality) to be culturally universal, but I recall debate on this point, and indeed find that debate covered by cited references (17,18) at the end of the article. Their core observation is that when men view photographs of women after and before plastic surgery to achieve an optimal (~0.7) waist to hip ratio (with redistributed body fat but relatively unaffected body mass index), an increase in activation of brain rewards centers can be observed. They suggest their observations "are the first description of a neural correlate implicating waist to hip ratio as a putative honest biological signal of female reproductive viability and its effects on men's neurological processing."
Wednesday, February 24, 2010
During happy hour at my local watering hole, I frequently pull out my iPhone and do a bit of random web cruising. Several nights ago this yielded this piece on effects of internet use on our intelligence, suggesting extensive internet use makes us different, but not dumb. The article cites a Pew Study reporting, contra an influential article by Nicholas Carr, that 76 percent of the respondents said they agree that by 2020, "people’s use of the Internet has enhanced human intelligence; as people are allowed unprecedented access to more information, they become smarter and make better choices. The article also relays the opinions of a number of other futurists.
Here is a fascinating open access article well worth having a look at:
Emotional signals are crucial for sharing important information, with conspecifics, for example, to warn humans of danger. Humans use a range of different cues to communicate to others how they feel, including facial, vocal, and gestural signals. We examined the recognition of nonverbal emotional vocalizations, such as screams and laughs, across two dramatically different cultural groups. Western participants were compared to individuals from remote, culturally isolated Namibian villages. Vocalizations communicating the so-called “basic emotions” (anger, disgust, fear, joy, sadness, and surprise) were bidirectionally recognized. In contrast, a set of additional emotions was only recognized within, but not across, cultural boundaries. Our findings indicate that a number of primarily negative emotions have vocalizations that can be recognized across cultures, while most positive emotions are communicated with culture-specific signals.
Tuesday, February 23, 2010
Over the past several years I've done a number of posts on brain correlates of spirituality, in particular work on lesions or temporal lobe seizures that induce mystical or spiritual states (click the religion topic in the left column to find them). Urgesi et al. have now done a clinical study on selective cortical lesions that modulate human self transcendence. They 88 brain cancer patients to fill out a widely used personality questionnaire before and after surgery to remove their tumors. One section of the test measured "self transcendence." It asked respondents, for example, about their tendency to become so absorbed in an activity that they lose track of time and place and whether they feel a strong spiritual connection with other people or with nature. They found that selective damage to left and right inferior posterior parietal regions induced a specific increase of self-transcendence. Other studies have found that some of the same regions become active during prayer and meditation. These posterior parietal brain regions have been implicated in providing awareness of the body's position and location in space.
Figure - Lesion Correlates of Increased and Decreased Self Transcendence. The authors found two clusters of voxels located in the left inferior parietal lobe (L-IPL; A) and in the right angular gyrus (R-AG; B) whose damage was associated with a significant ST increase.
Posted by Deric Bownds at 4:31 AM
Monday, February 22, 2010
A well known demonstration of how our brain makes assumptions about what is happening 'out there' on the basis of very limited input is the 'Cutaneous Rabbit' demonstration. If rapid sequential taps are delivered to two points on our skin, we also feel sequential taps at points intermediate between the two, as if a small rabbit were hopping along our skin. The assumption has been that this illusion is link to our somatotopic sensory cortex, which continuously maps the skin surface. Miyazaki et al. show that this illusion can be moved to an external object - a stick held between our left and right index fingers. Here is the abstract from their open access article:
Rapid sequential taps delivered first to one location and then to another on the skin create the somatosensory illusion that the tapping is occurring at intermediate locations between the actual stimulus sites, as if a small rabbit were hopping along the skin from the first site to the second (called the "cutaneous rabbit"). Previous behavioral studies have attributed this illusion to the early unimodal somatosensory body map. A functional magnetic resonance imaging study recently confirmed the association of the illusion with somatotopic activity in the primary somatosensory cortex. Thus, the cutaneous rabbit illusion has been confined to one's own body. In the present paper, however, we show that the cutaneous rabbit can "hop out of the body" onto an external object held by the subject. We delivered rapid sequential taps to the left and right index fingers. When the subjects held a stick such that it was laid across the tips of their index fingers and received the taps via the stick, they reported sensing the illusory taps in the space between the actual stimulus locations (i.e., along the stick). This suggests that the cutaneous rabbit effect involves not only the intrinsic somatotopic representation but also the representation of the extended body schema that results from body–object interactions.
Friday, February 19, 2010
Working with retired professional pianist David Goldberger, I'm preparing for a 4-hands recital on Sunday, March 7 in Fort Lauderdale. I decided to make a few rehearsal recordings, to be eventually replaced by a final version. The video below is of a palatable, but we think much less than optimal, run through of the Allegro (first movement) of Mozart's Piano Sonata for 4-hands, K. 358. We will also be doing the Schubert Fantasy for 4-hands.
A sobering account from Chen et al.:
Disparities by socioeconomic status (SES) are seen for numerous mental and physical illnesses, and yet understanding of the pathways to health disparities is limited. We tested whether SES alters longitudinal trajectories of cortisol output and what types of psychosocial factors could account for these links. Fifty healthy children collected saliva samples (four times per day for 2 days) at 6-month intervals for 2 years. At baseline, families were interviewed about SES and psychosocial factors. Lower-SES children displayed greater 2-year increases in daily cortisol output compared with higher-SES children. These effects were partially mediated by children’s perceptions of threat and by family chaos. These findings may help explain, and provide some first steps toward ameliorating, low-SES children’s vulnerability to health problems later in life by identifying the tendency to perceive threat in ambiguous situations and experiences of chaos as factors that link low SES to 2-year hormonal trajectories.
Thursday, February 18, 2010
Beilock et al. make some interesting observations:
People’s fear and anxiety about doing math—over and above actual math ability—can be an impediment to their math achievement. We show that when the math-anxious individuals are female elementary school teachers, their math anxiety carries negative consequences for the math achievement of their female students. Early elementary school teachers in the United States are almost exclusively female (more than 90%), and we provide evidence that these female teachers’ anxieties relate to girls’ math achievement via girls’ beliefs about who is good at math. First- and second-grade female teachers completed measures of math anxiety. The math achievement of the students in these teachers’ classrooms was also assessed. There was no relation between a teacher’s math anxiety and her students’ math achievement at the beginning of the school year. By the school year’s end, however, the more anxious teachers were about math, the more likely girls (but not boys) were to endorse the commonly held stereotype that “boys are good at math, and girls are good at reading” and the lower these girls’ math achievement. Indeed, by the end of the school year, girls who endorsed this stereotype had significantly worse math achievement than girls who did not and than boys overall. In early elementary school, where the teachers are almost all female, teachers’ math anxiety carries consequences for girls’ math achievement by influencing girls’ beliefs about who is good at math.
Wednesday, February 17, 2010
Nicholas Kristoff does a nice piece on a topic I have done several previous posts on - fundamental differences in the wiring of conservative versus liberal brains - the central observation being that conservatives feel threat and revulsion much more readily than liberals, with corresponding physiological changes measured, for example, by the startle blink reflex or skin conductance. Kristoff discusses work showing a remarkably strong correlation between state attitudes toward spanking children and voting patterns. Essentially, spanking states go Republican, while those with more timeouts go Democratic.
Spankers tend to see the world in stark, black-and-white terms, perceive the social order as vulnerable or under attack, tend to make strong distinctions between “us” and “them,” and emphasize order and muscular responses to threats. Parents favoring timeouts feel more comfortable with ambiguities, sense less threat, embrace minority groups — and are less prone to disgust when they see a man eating worms.And, I thought this bit was interesting:
I moaned to the scholars that their research was utterly dispiriting for those of us in the opinion business. After all, it’s extra challenging to try to change people’s minds if they may not even share our hard-wiring. Are people who are “wrong” on the issues beyond redemption, because of their physiological inability to help themselves?..Professors Hetherington and Smith dismissed my whining and were more sanguine. For starters, they note that physiological differences are probably found among the extremes on each side, while political battles are fought in the middle. Indeed, these studies may be useful in determining what arguments to deploy against the other side...“What research like ours may help with is in figuring out how to construct an argument in a way that is going to meaningfully connect with those on the other side,” Dr. Smith said.
Conservatives may be more responsive to health reform, he suggested, if it is framed as a national security argument. For example, American companies complain about the difficulty of competing with foreign companies that don’t have to pay for employee medical coverage. In that sense, our existing health care system leaves us vulnerable...That foreign threat might make conservatives sweat so much that maybe, just maybe, they’d consider revisiting the issue.
Tuesday, February 16, 2010
My son pointed me to work by Wobber et al. which makes me feel much better about my curmudgeonly nature. They compared the behavior of Chimpanzees, who can be quite grumpy, that that of Bonobos, who maintain childlike playfulness throughout their lives. They suggest the chimps' ability to put aside their sociability is one of the reasons they are more intelligent and civilized than their genetically similar great ape cousins. Perhaps being aggressive, intolerant and short-tempered could be a sign of a more advanced nature! Here is their abstract:
Phenotypic changes between species can occur when evolution shapes development. Here, we tested whether differences in the social behavior and cognition of bonobos and chimpanzees derive from shifts in their ontogeny, looking at behaviors pertaining to feeding competition in particular. We found that as chimpanzees (n = 30) reached adulthood, they became increasingly intolerant of sharing food, whereas adult bonobos (n = 24) maintained high, juvenile levels of food-related tolerance. We also investigated the ontogeny of inhibition during tasks that simulated feeding competition. In two different tests, we found that bonobos (n = 30) exhibited developmental delays relative to chimpanzees (n = 29) in the acquisition of social inhibition, with these differences resulting in less skill among adult bonobos. The results suggest that these social and cognitive differences between two closely related species result from evolutionary changes in brain development.
Monday, February 15, 2010
My apologies (and this surely falls under the 'random curious stuff' category) but I can't resist passing on this hysterical cat video.
Have you ever noticed that the first cowboy to draw his gun in a Hollywood Western is invariably the one to get shot? Nobel prize–winning physicist Niels Bohr did, once arranging mock duels to test the validity of this cinematic curiosity.
Welchman's team organized simulated "gunfights" in the laboratory, with pairs of volunteers competing against each other to push three buttons on a computer console in a particular order. The researchers observed that the time interval between when players removed their hands from the first button and when they pressed the final button was on average 9% shorter for the players who reacted to an opponent moving first. However, those who reacted to a first move were more likely to make an error, presssing the buttons in the wrong order. Welchman speculates that this rapid, if somewhat inaccurate, response system may have evolved to help humans deal with danger, when immediate reaction is essential and the risk of an error worth taking.
Friday, February 12, 2010
Added note: A bit of web cruising yields this information on how that small downloaded App (Moodagent Profilter) has managed to let Moodagent draw items from my whole iTunes library.
Moodagent Profiler desktop app, like Apple’s Genius function, goes through your iTunes library and uploads anonymous information about your iTunes tracks to the Moodagent server. The more people who use the app and index their music, the better Moodagent’s database will get.
Thursday, February 11, 2010
An interesting open access article from Litt (something you knew already, but psychologists gotta have something to measure!):
We show how being “jilted”—that is, being thwarted from obtaining a desired outcome—can concurrently increase desire to obtain the outcome, but reduce its actual attractiveness. Thus, people can come to both want something more and like it less. Two experiments illustrate such disjunctions following jilting experiences. In Experiment 1, participants who failed to win a prize were willing to pay more for it than those who won it, but were also more likely to trade it away when they ultimately obtained it. In Experiment 2, failure to obtain an expected reward led to increased choice, but also negatively biased evaluation, of an item that was merely similar to that reward. Such disjunctions were exhibited particularly by individuals low in intensity of felt affect, a finding supporting an emotional basis for relative harmonization of wanting and liking. These results demonstrate how dissociable psychological subsystems for wanting and liking can be driven in opposing directions.
Wednesday, February 10, 2010
MindBlog has done a number of posts on behavioral effects of oxytocin and vasopressin in humans (enter the terms in the search box in the left column to see them). Taylor et al. now show, in an open access article, that they may be biomarkers of distressed relationships:
Young adults in couple (pair-bond) relationships reported on the positive and negative aspects of their relationships and had blood drawn and assayed for oxytocin and vasopressin. Elevated plasma oxytocin was associated with distress in the pair-bond relationship for women, but not for men. Vasopressin, which is closely related to oxytocin in molecular structure and significantly related to male pair-bond behavior in animal studies, was elevated in men experiencing distress in the pair-bond relationship, but not in women. Controlling for estradiol and testosterone did not alter these findings. We conclude that plasma oxytocin in women and plasma vasopressin in men may be biomarkers of distressed pair-bond relationships.
Tuesday, February 09, 2010
Movements of our muscles influence our thoughts and emotions. People given neutral bland instructions to contract the specific face muscles that make a smile find it harder to generate a feeling of anger when requested to do so, and instruction to move the muscles that make an angry frown make it harder to follow a subsequent instruction to feel friendly or happy. Havas has found that blocking a frown can actually prevent a bad mood. Natalie Angier summarizes several studies that show the opposite: how thoughts influence our muscle movements in subtle ways. Miles et al., for example, show that when we thing of events in the future, our bodies move slightly forward, while thinking of past events causes them to move slightly backwards. Their observations are consistent with theories of "embodied cognition," in this case mental time travel may be represented in the sensorimotor systems that regulate human movement. The metaphorical “arrow of time” may be grounded in a processing architecture that integrates temporal and spatial information in a directional manner (i.e., past = back, future = forward).
Angier also notes other work on embodied cognition that I have mentioned - Students who held a hot cup of coffee in their hand were more likely to evaluate a target person as being warm and friendly than those holding a cold cup of coffee. She notes work (this post) showing that a warm versus cold stare causes subject to evaluate the temperature of a room as warmer. Finally she points to work (this post) showing our bodies conflate weight with greater importance or value. (...almost makes you think that both Angier and Bownds scan the contents of the journal "Psychological Science.")
Monday, February 08, 2010
As year five of this blog starts, I find it hard to believe that I have banged out over 2,000 postings, that the blog has ~1,500 RSS feed subscribers, and is seriously engaged by 300-400 people on an average day.
About this time of year I usually cycle through an identity crisis regarding what kind of thinking and writing I want to do, how much energy to put into MindBlog. Sometimes external forces nudge my efforts. I recently got a curious invitation to an international Cognitive Neuroscience meeting in Istanbul next May 18-20. The request was that I both present a piano recital and also give a talk on the mind. I'm now working on the talk ("Who wants to know? - the nature of our subjective "I"), deciding on the music, and will eventually put the talk on my website, with a podcast version on this blog. I've done a few previous podcasts (see left column of blog), but haven't really gotten into it. I don't listen to podcasts, they seem so much less efficient than just reading. I started to play with Twitter (left column), but aside from a few spurts of activity, I also haven't gotten into it.
Ever since the 1999 publication of my book, The Biology of Mind, I have puttered with the idea of another book. This first book had been a 'crossover' effort, written to be useful both for college course instruction and also for the educated layperson. It was reasonably successful, got some good reviews, and by now has sold ~ 9,000 copies. For the first year or two after its publication both I and the reviewers assumed that there would be a second revised edition.
But as I began to organize an updated version over the next several years, I became tempted by the prospect of doing a pure trade book, not a textbook. I got as far as a fairly complete book outline and design. Then I toyed with the idea of a short paragraph-a-day popular book, a bit of test writing being Mindstuff: bon-bons for the curious user posted on my website in 2002. Then in 2005 I attempted a still short but more continuous text: Mindstuff: a guide for the curious user. (On re-reading, it comes off as ponderous and impenetrable.) None of these efforts got to the level of seriously writing for publication - mainly because I was observing an exponential increase in the number of popular books on the mind, and thought it very likely that my effort would be lost in the noise.
I started Deric's MindBlog in early 2006, after reading a New York Times article on the blog phenomenon, and found myself reaching a larger audience than the previous writing efforts had generated, with much more feedback and interaction. Generating this blog provided a very useful excuse for doing all the reading I was doing anyway, for my own pleasure and stimulation - I could feel less self-indulgent if I was passing some of the material on.
The problem with the blog gig, which I have mentioned before, is that it is a very episodic, present-centered, non-cumulative activity - a very different mindset from the deeper and more continuous thinking that goes into doing a book. I don't think I have the time, motivation, or energy to do both kinds of activities.
This thinking-out-loud gets me to the point of rambling further about a book title that has been popping into my head for at least the last ten years: "The 100 Millisecond Manager." (a riff on the title the popular book of the early 1980's by Blanchard and Johnson, "The One Minute Manager.") The gist of the argument would be that given in the "Guide" section of the 2005 writing I mentioned above, and actually in Chapter 12 of my book, Figure 12-7.
It might make the strident assertion that the most important thing that matters in regulating our thoughts, feelings, and actions is their first 100-200 msec in the brain, which is when the levers and pulleys are actually doing their thing. It would be a nuts and bolts approach to altering - or at least inhibiting - self limiting behaviors. It would suggest that a central trick is to avoid taking on on the ‘enormity of it all,’ and instead use a variety of techniques to get our awareness down to the normally invisible 100-200 msec time interval in which our actions are being programmed. Here we are talking mechanical, not ideological; this is where all the limbic routines that result from life script, self image, temperament, etc., actually get their start-up. The suggestion is that you can short circuit the whole process if you simply bring awareness to the level of observing the moments during which a behavior switches on, and can sometimes say “I don’t think so.”
"The 100 msec Manager" has gone through the ‘this could be a book’ cycle several times over the past ten years, the actual execution then bogging down as I actually got into description of the underlying science and techniques for expanding awareness. I keep searching for keys to making it feisty, punchy, accessible, and attractive to readers. I note the enormous number of books out there on meditation, relaxation, etc. that are all really addressing the same core processes in different ways. How attractive or effective would be an approach that didn't have the slightest whiff of 'spirituality' or 'purpose' be? (I think that spirituality and purpose are human inventions, culturally evolved psychologies, not shared with other animals, that help humans pass on their genes.)
So.... for the moment all this waffling brings me back to thinking that just doing this blog isn't such a bad deal after all.
Gregory Paul makes an interesting comment on an article by Cullota that was the subject of my Nov. 17 post. I think his point that belief in gods and an afterlife is unlikely to be a "strongly genetically programmed result of major selective evolutionary pressures such as social cohesion" is a good one. But, I assume he would agree that there is genetic/development programming of things like the facial muscles that are specialized for signaling affiliative gestures that are universal across cultures. Here is his letter:
The Science News Focus story "On the origin of religion" (E. Culotta, 6 November 2009, p. 784) did not incorporate the growing body of psychosociological research that is revealing the crucial role of socioeconomics in the origin and popularity of religion, as well as in creationism (1–6). Some hunter-gatherers have minimal religion (7), and those who do not believe in the gods and an afterlife have spontaneously expanded in prosperous democracies until they are the majority in some nations, such as France, Sweden, and Denmark (1, 3, 4). Because religion is not universal, as implied in the News Focus article, serious religiosity cannot be the strongly genetically programmed result of major selective evolutionary pressures such as social cohesion (8).
In modern nations, nonreligion and the acceptance of evolution become popular when the middle class majority feels sufficiently secure and safe, thanks to low income inequality, universal health care, job and retirement security, and low rates of lethal crime; this has occurred to greater and lesser degrees in most first-world countries, from Japan to Scandinavia (1–6). Religion thrives when the majority seek the aid and protection of supernatural powers because they are impoverished, as in the third- and second-world countries or, in the case of the United States (the most religious and creationist first-world country), because the majority of Americans fear losing their middle-class status as a result of limited government support, high levels of social pathology, and intense economic competition and income disparity (1–6). Prosperous modernity is proving to be the nemesis of religion.
* 1. G. Paul, Evol. Psychol. 7, 398 (2009); www.epjournal.net/filestore/EP07398441_c.pdf.
* 2. T. Rees, J. Relig. Soc. 11 (2009); moses.creighton.edu/JRS/2009/2009-17.html.
* 3. P. Zuckerman, Soc. Compass 3, 949 (2009). [CrossRef]
* 4. P. Norris, R. Inghelart, Sacred and Secular (Cambridge Univ. Press, Cambridge, 2004).
* 5. A. Gill, E. Lundsgaarde, Rational. Soc. 16, 399 (2004). [CrossRef]
* 6. S. Verweii, P. Ester, R. Naata, J. Sci. Study Relig. 36, 309 (1997). [CrossRef] [Web of Science]
* 7. F. Marlowe, in Ethnicity, Hunter-Gatherers, and the "Other," S. Kent , Ed. (Smithsonian Institute Press, Washington, DC, 2002), pp. 247–281.
* 8. C. N. Wade, The Faith Instinct (Penguin, New York, 2009).
Friday, February 05, 2010
How do we resist impulsive desires? Apparently our anteroventral prefrontal cortex tells our nucleus accumbens and ventral tegmental areas (involved in reward and pleasure) to chill out. From Diekhof and Gruber:
Human decisions are guided by "desire" or "reason," which control actions oriented toward either proximal or long-term goals. Here we used functional magnetic resonance imaging to assess how the human brain mediates the balance between proximal reward desiring and long-term goals, when actions promoting a superordinate goal preclude exploitation of an immediately available reward option. Consistent with the view that the reward system interacts with prefrontal circuits during action control, we found that behavior favoring the long-term goal, but counteracting immediate reward desiring, relied on a negative functional interaction of anteroventral prefrontal cortex (avPFC) with nucleus accumbens (Nacc) and ventral tegmental area. The degree of functional interaction between avPFC and Nacc further predicted behavioral success during pursuit of the distal goal, when confronted with a proximal reward option, and scaled with interindividual differences in trait impulsivity. These findings reveal how the human brain accomplishes voluntary action control guided by "reason," suggesting that inhibitory avPFC influences Nacc activity during actions requiring a restraint of immediate "desires."
Thursday, February 04, 2010
Tero et al. show that a slime mold in one day can design a network that is as efficient as one developed by humans over many years: the Tokyo rail system. Here is their abstract, followed by two figures:
Transport networks are ubiquitous in both social and biological systems. Robust network performance involves a complex trade-off involving cost, transport efficiency, and fault tolerance. Biological networks have been honed by many cycles of evolutionary selection pressure and are likely to yield reasonable solutions to such combinatorial optimization problems. Furthermore, they develop without centralized control and may represent a readily scalable solution for growing networks in general. We show that the slime mold Physarum polycephalum forms networks with comparable efficiency, fault tolerance, and cost to those of real-world infrastructure networks—in this case, the Tokyo rail system. The core mechanisms needed for adaptive network formation can be captured in a biologically inspired mathematical model that may be useful to guide network construction in other domains.
Fig. 1 Network formation in Physarum polycephalum. (A) At t = 0, a small plasmodium of Physarum was placed at the location of Tokyo in an experimental arena bounded by the Pacific coastline (white border) and supplemented with additional food sources at each of the major cities in the region (white dots). The horizontal width of each panel is 17 cm. (B to F) The plasmodium grew out from the initial food source with a contiguous margin and progressively colonized each of the food sources. Behind the growing margin, the spreading mycelium resolved into a network of tubes interconnecting the food sources.
Fig. 2 Comparison of the Physarum networks with the Tokyo rail network. (A) In the absence of illumination, the Physarum network resulted from even exploration of the available space. (B) Geographical constraints were imposed on the developing Physarum network by means of an illumination mask to restrict growth to more shaded areas corresponding to low-altitude regions. The ocean and inland lakes were also given strong illumination to prevent growth. (C and D) The resulting network (C) was compared with the rail network in the Tokyo area (D). (E and F) The minimum spanning tree (MST) connecting the same set of city nodes (E) and a model network constructed by adding additional links to the MST (F).
I wanted to pass on the link to this interesting article by Daniel Smith that discusses the psychological maladies that accompany ecological degradation. A few clips:
...Ecopsychology embraces a more revolutionary paradigm: just as Freud believed that neuroses were the consequences of dismissing our deep-rooted sexual and aggressive instincts, ecopsychologists believe that grief, despair and anxiety are the consequences of dismissing equally deep-rooted ecological instincts...a number of psychiatrically inflected coinages have sprung up to represent people’s growing unease over the state of the planet — “nature-deficit disorder,” “ecoanxiety,” “ecoparalysis.”
It was Bateson’s belief that the tendency to think of mind and nature as separate indicated a flaw at the core of human consciousness. Writing several years after Rachel Carson’s “Silent Spring,” at a time when the budding environmental movement was focused on the practical work of curbing DDT and other chemical pollutants, Bateson argued that the essential environmental crisis of the modern age lay in the realm of ideas. Humankind suffered from an “epistemological fallacy”: we believed, wrongly, that mind and nature operated independently of each other. In fact, nature was a recursive, mindlike system; its unit of exchange wasn’t energy, as most ecologists argued, but information. The way we thought about the world could change that world, and the world could in turn change us.
So what to do? How do you go about rebooting human consciousness? Bateson’s prescription for action was vague. We needed to correct our errors of thought by achieving clarity in ourselves and encouraging it in others — reinforcing “whatever is sane in them.” In other words, to be ecological, we needed to feel ecological. It isn’t hard to see why Bateson’s ideas might appeal to ecopsychologists. His emphasis on the interdependence of the mind and nature is the foundation of ecotherapy. It is also at the root of Kahn’s notion that “rewilding” the mind could have significant psychological benefits. But it also isn’t hard to see how the seeming circularity of Bateson’s solution — in order to be more ecological, feel more ecological — continues to bedevil the field and those who share its interests.
Wednesday, February 03, 2010
From Herdener et al. :
Training can change the functional and structural organization of the brain, and animal models demonstrate that the hippocampus formation is particularly susceptible to training-related neuroplasticity. In humans, however, direct evidence for functional plasticity of the adult hippocampus induced by training is still missing. Here, we used musicians' brains as a model to test for plastic capabilities of the adult human hippocampus. By using functional magnetic resonance imaging optimized for the investigation of auditory processing, we examined brain responses induced by temporal novelty in otherwise isochronous sound patterns in musicians and musical laypersons, since the hippocampus has been suggested previously to be crucially involved in various forms of novelty detection. In the first cross-sectional experiment, we identified enhanced neural responses to temporal novelty in the anterior left hippocampus of professional musicians, pointing to expertise-related differences in hippocampal processing. In the second experiment, we evaluated neural responses to acoustic temporal novelty in a longitudinal approach to disentangle training-related changes from predispositional factors. For this purpose, we examined an independent sample of music academy students before and after two semesters of intensive aural skills training. After this training period, hippocampal responses to temporal novelty in sounds were enhanced in musical students, and statistical interaction analysis of brain activity changes over time suggests training rather than predisposition effects. Thus, our results provide direct evidence for functional changes of the adult hippocampus in humans related to musical training.
Tuesday, February 02, 2010
Two random items on exercise. Work by Lieberman et al. on running has caused quite a stir in the press (and two MindBlog readers have pointed it out to me). I've tried taking off my running shoes for a few days now, and wow.... this is good stuff. (This should not have surprised me of course...I ran around barefoot for years as a kid growing up in Austin, Texas.) Here's the abstract:
Humans have engaged in endurance running for millions of years, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.A second item concerns exercise and longevity. Larocca et al. show that exercise delays the normal shortening of telomeres that occurs on aging. (Telomeres are tiny caps on the end of DNA strands, long strands of DNA that are snipped when cells divide, a process that is believed to protect the rest of the DNA but leaves an increasingly abbreviated telomere. Eventually, if a cell’s telomeres become too short, the cell either dies or enters a kind of suspended state.)
Having just done a post on brain changes on aging that increase financial risk taking I thought it appropriate to follow up with another article I came across from Crişan et al. who link genetic changes in a serotonin transporter to social learning of fear and economic decision making. Their abstract:
Serotonin (5-HT) modulates emotional and cognitive functions such as fear conditioning (FC) and decision making. This study investigated the effects of a functional polymorphism in the regulatory region (5-HTTLPR) of the human 5-HT transporter (5-HTT) gene on observational FC, risk taking and susceptibility to framing in decision making under uncertainty, as well as multidimensional anxiety and autonomic control of the heart in healthy volunteers. The present results indicate that in comparison to the homozygotes for the long (l) version of 5-HTTLPR, the carriers of the short (s) version display enhanced observational FC, reduced financial risk taking and increased susceptibility to framing in economic decision making. We also found that s-carriers have increased trait anxiety due to threat in social evaluation, and ambiguous threat perception. In addition, s-carriers also show reduced autonomic control over the heart, and a pattern of reduced vagal tone and increased sympathetic activity in comparison to l-homozygotes. This is the first genetic study that identifies the association of a functional polymorphism in a key neurotransmitter-related gene with complex social–emotional and cognitive processes. The present set of results suggests an endophenotype of anxiety disorders, characterized by enhanced social learning of fear, impaired decision making and dysfunctional autonomic activity.
Monday, February 01, 2010
Samanez-Larkin et al. first note research that shows that older adults make more errors when making risky decisions (In the domain of finance, healthy older investors have been shown to continue to invest in risky assets even after suffering losses in the stock market large enough to necessitate postponing retirement.) Then, using an investment task, the authors confirm that older adults make more risk-seeking mistakes, and find that these mistakes are mediated by increased temporal variability in the Nucleus Accumbens. Their findings indicate an age-related subcortical deficit that may promote risky decision-making mistakes. Here is their abstract:
As human life expectancy continues to rise, financial decisions of aging investors may have an increasing impact on the global economy. In this study, we examined age differences in financial decisions across the adult life span by combining functional neuroimaging with a dynamic financial investment task. During the task, older adults made more suboptimal choices than younger adults when choosing risky assets. This age-related effect was mediated by a neural measure of temporal variability in nucleus accumbens activity. These findings reveal a novel neural mechanism by which aging may disrupt rational financial choice.
I thought this Op-Ed piece by David Brooks was worth passing on. He notes that populism and elitism are really mirror images of one another, both manichean simplifications of complex multidimensional issues into stark good and evil extremes.