Friday, December 29, 2006

Challenging the link between the human microcephalin gene, evolution, and cognition.

Michael Balter writes an interesting account in Science Magazine over the controversy over the interpretation of data on the microcephalin gene, a gene that regulates brain size. (Microcephaly is the congenital or developmental disorder in which the circumference of the head is smaller than normal because the brain has not developed properly or has stopped growing. )

" two papers in Science last year, Lahn reported that variants of the two genes appear to have been strongly favored by recent natural selection (Science, 9 September 2005, pp. 1717 and 1720). That implies that the variants conferred a survival or reproductive benefit, perhaps a cognitive one. In media interviews, Lahn conceded that there was no real evidence natural selection had acted on cognition or intelligence. But both papers pointed out that the mutations arose when key events in human cultural development occurred: The microcephalin variant was dated to about 37,000 years ago, when the first art and symbolism showed up in Europe, and the ASPM variant to 5800 years ago, when the first cities arose.

Lahn's papers also reported the skewed geographic distribution of the genetic variants. Variants in microcephalin turned up in 75% or more of some Europeans and Asians Lahn studied, but in less than 10% of some African groups. The ASPM variant was also much less frequent in Africa. (click on graphic to enlarge).

Bloggers jumped on the news, trumpeting the papers as support for the idea that African Americans have lower intelligence than whites. Two months later, in the conservative National Review Online, columnist John Derbyshire wrote that the research implied that "our cherished national dream of a well-mixed and harmonious meritocracy … may be unattainable."

"Soon after the Science papers were published, Lahn set out to see whether the variants give a cognitive advantage. In one study, Lahn helped controversial psychologist Philippe Rushton of the University of Western Ontario in London, Canada, test whether people who carry the favored variants have higher IQs. Rushton is well known for his claims that African Americans have lower intelligence than whites, and Lahn had found that some genetic variants are common in Europeans and Asians but less frequent among sub-Saharan Africans. But Rushton reported last week at the annual meeting of the International Society for Intelligence Research in San Francisco, California, that he had struck out: The variants conferred no advantage on IQ tests. "[We] had no luck," Rushton told Science, "no matter which way we analyzed the data." Lahn was not a co-author, but his group genotyped the 644 adults of differing ethnicity in the study."

Among some geneticists, there was consternation. "There was no evidence whatsoever that these [genetic variants] have any effect" on differences between people, Altshuler says, adding that the controversy over the work was "easily anticipated." Harvard geneticist Richard Lewontin goes further, criticizing both Lahn and Science for publishing such speculative links to cultural advances. "These two papers are particularly egregious examples of going well beyond the data to try to make a splash," he says. And archaeologist Scott MacEachern of Bowdoin College in Brunswick, Maine, says the archaeological links in the papers are simplistic and outdated. The symbolic revolution, agriculture, and urbanism developed "over many thousands of years, and none was restricted to Europe and the Middle East," he says."

Thursday, December 28, 2006

Actions speak louder than brain images.

There is growing concern over the pseudoscientific use of brain imaging to predict behaviors or assign a character type. Apoorva Mandavilli writes a short essay on this topic in the Dec. 7 issue of Nature Magazine.

"Can brain scans of a racist, liar or psychopath accurately tell whether that person will persecute, fib or kill? No, say experts in the ethics of neuroscience, who are increasingly concerned that such images will be used to make dangerous legal or social judgements about people's behaviour. They say it is time for scientists, lawyers and philosophers to speak up about the limitations of such techniques....interpreting brain scans, and correlating them to actions, is inaccurate at best. All we can really gain from such studies is a more nuanced understanding of behaviour...studies of behavioural or physical responses — for example, a person's reaction to different races in real life — should trump imaging every time...The legal and moral claims being made[ from imaging studies involving very few people] are far too extensive."

" In a landmark case in the US Supreme Court in March 2005, several leading scientific groups, including the American Medical Association, the American Psychiatric Association and the National Mental Health Association, filed briefs to support the premise that teenagers are less rational than adults.

The data included a brain-imaging study showing that the prefrontal cortex, which governs impulse control and reasoning, develops late in adolescence (see Nature 442, 865–867; 2006), and could explain some irrational aspects of teenage behaviour."

"Many groups thought this study could help rule against the death penalty. But although the court ruled against the death penalty for those younger than 18, it chose not to cite the brain-imaging study, relying instead on behavioural studies that showed adolescents are more impulsive, more vulnerable to peer pressure and more affected by stress."

Brain self repair

Jan's laboratory at UCSF (Cell Volume 127, Issue 6, 15 December 2006) has looked at an area of the brain known as the subventricular zone (SVZ). They showed that a gene called Numb regulates how stem cells from the SVZ become neurons, and instructs these cells to maintain the walls of the lateral ventricles, the brain's central cavities.

With Numb knocked out, mice developed large holes in these walls. But, rather than worsening over time, the holes were repaired within 6 weeks. The team suggests that stem cells that escaped the knockout were able to shore up the walls. Such capacity for do-it-yourself repair might be harnessed to treat brain damage.

Wednesday, December 27, 2006

A bull market in Brain Fitness and Calisthenics

I've been meaning for some time to do a post on the avalanche of interest in aging baby boomers not loosing their marbles any faster than absolutely necessary. An article on this topic by Pam Belluck in the 12/27/06 New York Times prompts me to go ahead. We are seeing a blooming of blogs and start up companies that focus on techniques for preserving memory and mental acuity (Posit Science, Third Age, Vigorous Mind, Rocky Mountain Learning, Sharp Brains, Happy Neuron, My Brain Trainer, to mention just a few). The Developing Intelligence blog has a post that discusses the Sharp Brains company, and the Sharp Brains Blog and the Brain Reserves Blog are among several that focus on brain fitness.

There are positive individual testimonials to the effectiveness of brain exercises, and a number of group studies are underway, but we are still absent any hard data that brain exercises bring a benefit that is distinguishable from general cardiovascular exercise. Belluck notes "human studies have generally relied on observations of people with healthier brains, but have not tested whether a particular behavior improves brain health. Perhaps people with healthier brains are more likely to do brain-stimulating activities, not the reverse." She also makes the point: "Certainly most brain-healthy recommendations are not considered bad for people. They do not have the potential risks of drugs or herbal supplements... The challenge we have is it’s going to be a lot like the anti-aging industry: how much science is there behind this?"

Synchronies to bind our brains... check out the movie

A commentary by Sporns and Honey and an article by Bassett et al in PNAS delve into (quoting Spors and Honey) "explaining how functional brain states emerge from the interactions of dozens, perhaps hundreds, of brain regions, each containing millions of neurons. Much evidence supports the view that highly evolved nervous systems are capable of rapid, real-time integration of information across segregated sensory channels and brain regions. This integration happens without the need for a central controller or executive: It is the functional outcome of dynamic interactions within and between the complex structural networks of the brain... the study by Bassett et al. reveals the existence of large-scale functional networks in magnetoencephalographic (MEG) recordings with attributes that are preserved across multiple frequency bands and that flexibly adapt to task demands. These networks exhibit "small-world" structure, i.e., high levels of clustering and short path lengths. The authors' analysis reveals that the small-world topology of brain functional networks is largely preserved across multiple frequency bands and behavioral tasks."

From Bassett et al: "Coherent or correlated oscillation of large-scale, distributed neural networks is widely regarded as an important physiological substrate for motor, perceptual and cognitive representations in the brain...The topology of networks can range from entirely random to fully ordered (a lattice). In this spectrum, small-world topology is characteristic of complex networks that demonstrate both clustered or cliquish interconnectivity within groups of nodes sharing many nearest neighbors in common (like regular lattices), and a short path length between any two nodes in the network (like random graphs). This is an attractive configuration, in principle, for the anatomical and functional architecture of the brain, because small-world networks are known to optimize information transfer, increase the rate of learning, and support both segregated and distributed information processing."

"Magnetoencephalographic data were acquired from 22 subjects, half of whom performed a finger-tapping task, whereas the other half were studied at rest. Signals were recorded from a set of 275 points overlying the scalp surface, to provide a time-frequency decomposition of human brain activity... brain functional networks were characterized by small-world properties at all six wavelet scales considered, corresponding approximately to classical {delta} (low and high), {theta}, {alpha}, beta, and {gamma} frequency bands. Global topological parameters (path length, clustering) were conserved across scales, most consistently in the frequency range 2–37 Hz, implying a scale-invariant or fractal small-world organization. Dynamical analysis showed that networks were located close to the threshold of order/disorder transition in all frequency bands. The highest-frequency {gamma} network had greater synchronizability, greater clustering of connections, and shorter path length than networks in the scaling regime of (lower) frequencies. Behavioral state did not strongly influence global topology or synchronizability; however, motor task performance was associated with emergence of long-range connections in both beta and {gamma} networks. Long-range connectivity, e.g., between frontal and parietal cortex, at high frequencies during a motor task may facilitate sensorimotor binding. Human brain functional networks demonstrate a fractal small-world architecture that supports critical dynamics and task-related spatial reconfiguration while preserving global topological parameters."

The above figure is a demonstration model by Sporns and Honey of the relationship of structural to functional connectivity networks consisting of a set of 1,600 modeled neural mean field units arranged on a sphere and engaging in noise-driven spontaneous activity. (A) The anatomical connection pattern, shown only for a few randomly selected neural units, consists of a mix of mostly local (clustered) connections and a few connections made over longer distances. (B) A snapshot and an EEG-like recording trace of the dynamical neuronal activity pattern. Neuronal dynamics is characterized by complex spatial and temporal structure across multiple scales [Click here to see a supporting movie]. (C) A functional connectivity network obtained from a thresholded correlation matrix calculated from the dynamics shown in B. In this example, both structural and functional connectivity patterns exhibit small-world attributes.

A review of MindBlog

A colleague recently pointed out this review of MindBlog, which I had completely missed. And to lay on another bit of self-promotion, let me remind you that "The Biology of Mind" has received good reviews and is a friendly read.

Tuesday, December 26, 2006

Thought without language - metacognition in Animals

The Dec. 15 issue of The New Scientist has an interesting article by Helen Philips, "The Known Unknown," about game playing in monkeys and dolphins that sheds light on their 'thinking about thinking' , knowing what they don't know - which appears to be a key step on the transition to full consciousnes. Here is a nice graphic from that article. (Click on the graphic to enlarge it).

In defense of order....

Check out this response by Jessica Duquette to the NY Times article on disorder that was the subject of yesterday's post. She argues "Neat is fluid and dynamic, not prissy and stuck." and cites another response to Green's NY Times essay: "There is a difference in a stagnate mess and an active mess. A desk with papers and notes changing daily shows activity. Mess that accumulates and stagnates is a sign of incompletion and unwillingness to go back over something, like cleaning up desk at the end of the day. I have found that things need to get moved around but also need a place to be so a person can find them when needed. That is a time saver, not a time waster. Not being able to find a tool to fix the light switch or hang a coat rack only adds to problem. Then you end up looking for your coat in dark when you’re in a hurry."

Monday, December 25, 2006

Disorder as the detritus of a creative mind...

This is the subtitle title of a recent essay in the New York Times, "Saying Yes to Mess", by Penelope Green. Being a tidy control freak (while my partner generates entropy and piles), I can't resist passing on some clips:

In the face of a booming home-organizing market (5.9 Billion last year), "An anti-anticlutter movement is afoot, one that says yes to mess and urges you to embrace your disorder. Studies are piling up that show that messy desks are the vivid signatures of people with creative, limber minds (who reap higher salaries than those with neat “office landscapes”) and that messy closet owners are probably better parents and nicer and cooler than their tidier counterparts. It’s a movement that confirms what you have known, deep down, all along: really neat people are not avatars of the good life; they are humorless and inflexible prigs, and have way too much time on their hands. "

David Freedman and Eric Abrahamson, in their forthcoming book "A Perfect Mess: The Hidden Benefits of Disorder," "describe the properties of mess in loving terms. Mess has resonance, they write, which means it can vibrate beyond its own confines and connect to the larger world. It was the overall scumminess of Alexander Fleming’s laboratory that led to his discovery of penicillin, from a moldy bloom in a petri dish he had forgotten on his desk....The book is a meandering, engaging tour of beneficial mess and the systems and individuals reaping those benefits, like Gov. Arnold Schwarzenegger, whose mess-for-success tips include never making a daily schedule."

"In the semiotics of mess, desks may be the richest texts. Messy-desk research borrows from cognitive ergonomics, a field of study dealing with how a work environment supports productivity. Consider that desks, our work landscapes, are stand-ins for our brains, and so the piles we array on them are “cognitive artifacts,” or data cues, of our thoughts as we work.

To a professional organizer brandishing colored files and stackable trays, cluttered horizontal surfaces are a horror; to cognitive psychologists like Jay Brand, who works in the Ideation Group of Haworth Inc., the huge office furniture company, their peaks and valleys glow with intellectual intent and showcase a mind whirring away: sorting, linking, producing. (By extension, a clean desk can be seen as a dormant area, an indication that no thought or work is being undertaken.)

His studies and others, like a survey conducted last year by Ajilon Professional Staffing, in Saddle Brook, N.J., which linked messy desks to higher salaries (and neat ones to salaries under $35,000), answer Einstein’s oft-quoted remark, “If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk?”

Friday, December 22, 2006

The giving season: food and money -an evolutionary link?

This short note from the Editor's choice section in the Dec. 22 issue of Science:

"Although the giving of gifts is a common activity at this time of year, giving a gift certificate has become an allowable substitute for giving money, which is generally regarded as unseemly. In order to explore whether money can serve not only as a useful instrument (for the purchase of material goods) but also as a valued resource, Briers et al. (Psychol. Sci. 17, 939 (2006) have carried out a series of experiments to see whether an unfulfilled desire for food (or money) might make one more tight-fisted (or more voracious). People who were hungry behaved less generously toward a charity (Médecins Sans Frontières) and in public goods games than those who had just eaten cake; conversely, people who were told to imagine being desirous of a substantial payoff (being in such a state was confirmed by how much their estimates of the size of a coin were skewed to be larger than actual) consumed more M&M's than those who were focused on a modest windfall. These results linking the rewarding character of food to that of money dovetail neatly with a recent study (Vohs et al., Science, Reports, p. 1154, 17 November 2006) that demonstrated money's value as a means of enhancing one's self-sufficiency and social independence.

Here is the abstract from Briers et al.:
This report attempts to provide an evolutionary explanation for humans' motivation to strive for money in present-day societies. We propose that people's desire for money is a modern derivate of their desire for food. In three studies, we show the reciprocal association between the incentive value of food and of money. In Study 1, hungry participants were less likely than satiated participants to donate to charity. In Study 2, participants in a room with an olfactory food cue, known to increase the desire to eat, offered less money in a give-some game compared with participants in a room free of scent. In Study 3, participants' desire for money affected the amount of M&M's® they ate in a subsequent taste test, but only among participants who were not restricting their food intake in order to manage their weight.

During sleep: a brain memory dialogue

It has been known for some time that specific patterns of nerve firing in "place cells" of the rat hippocampus occur during learning a visual maze and that these patterns are replayed during sleep, apparently as a part of memory consolidation. Wilson's laboratory at M.I.T. (reporting in Nature Neuroscience) have now studied multicell spiking patterns in both the visual cortex and hippocampus during slow-wave sleep in rats. As Nicholas Wade notes in the NYTimes, the recordings capture dialogue between the hippocampus, where initial memories of the day's events are formed, and the neocortex, the sheet of neurons on the outer surface of the brain that mediates conscious thought and contains long-term memories.

Ji and Wilson found that spiking patterns not only in the visual cortex but also in the hippocampus were organized into frames, defined as periods of stepwise increase in neuronal population activity. The multicell firing sequences evoked by awake experience were replayed during these frames in both regions. Furthermore, replay events in the sensory cortex and hippocampus were coordinated to reflect the same experience. These results imply simultaneous reactivation of coherent memory traces in the cortex and hippocampus during sleep that may contribute to or reflect the result of the memory consolidation process. Because the fast rewinds in the neocortex tended to occur fractionally sooner than their counterparts in the hippocampus, Wilson thinks the dialogue is probably being initiated by the neocortex, and reflects a querying of the hippocampus's raw memory data.

Wade's review quotes comments from Wilson:
“The neocortex is essentially asking the hippocampus to replay events that contain a certain image, place or sound...The neocortex is trying to make sense of what is going on in the hippocampus and to build models of the world, to understand how and why things happen...These models are presumably used to direct behavior...They are able to generate expectations about the world and plausibly fill in blanks in memory.

Though the neocortex learns from the hippocampus, the raw memory traces, from childhood onward, are not transferred and are probably retained in the hippocampus... If so, the forgetfulness of age would arise because of problems in accessing the hippocampus, not because the data has vanished.

The subject matter of the neocortex-hippocampus dialogue in rats seems mostly to concern recent events. This is consistent with what people report when awoken from nondreaming sleep — usually small snatches of information about recent events. Dr. Wilson also said that the new findings, by showing activity in the visual neocortex, confirmed that rats had humanlike dreams with visual imagery, a possibility some researchers had doubted."

Thursday, December 21, 2006

Mind Wars

I would like to recommend to you an interesting, authoritative, and well written book on the massive amount of research being conducted by the United States defense establishment on brain research relevant to:

- "bulding better humans" (for war purposes)
- controlling human behaviors through chemical or other means (DARPA funded early LSD experiments and Darpanet was the first name for the internet)
- "mind-reading" using imaging techniques
- brain-machine interfaces, 'borgs' (machine-human hybrids)
- improving battefield survivabiliy, making "sleepless" soliders, etc. etc.

The book is "Mind Wars: Brain Research and National Defense" by Jonathan D. Moreno, who holds a chair professorship and is Director of the Center for Biomedical Ethics at the University of Virginia. He does not argue for a separation of the academic research world and the national security establishment, but thinks that much more effort should go into formulating an "ethics of neurosecurity and neurodefense."

Wednesday, December 20, 2006

Abolishing pain with a single sodium channel mutation

Even though this blog is mainly about nervous systems, brains, and behaviors, I'm occasionally drawn back to my roots as a molecular biologist by a particularly outstanding example of how a single molecule can determine what we take to be a very complex experience - in this case the experience of pain. Cox et. al. have found that a mutation in the gene for a particular sodium channel subunit that is strongly expressed in the pain sensitivie endings of nociceptive (pain sensing and transmitting) neurons can abolish the ability to feel pain. The rare mutation was found in several individuals from a family in northern Pakistan who were unable to experience pain. This work should stimulate the search for novel analgesics that selectively target this sodium channel subunit.

The ususual human situation that permitted this work is described: "The index case for the present study was a ten-year-old child, well known to the medical service after regularly performing 'street theatre'. He placed knives through his arms and walked on burning coals, but experienced no pain. He died before being seen on his fourteenth birthday, after jumping off a house roof. Subsequently, we studied three further consanguineous families in which there were individuals with similar histories of a lack of pain appreciation, each originating from northern Pakistan and part of the Qureshi birdari/clan. All six affected individuals had never felt any pain, at any time, in any part of their body...All had injuries to their lips (some requiring later plastic surgery) and/or tongue (with loss of the distal third in two cases), caused by biting themselves in the first 4 yr of life. All had frequent bruises and cuts, and most had suffered fractures or osteomyelitis, which were only diagnosed in retrospect because of painless limping or lack of use of a limb. The children were considered of normal intelligence by their parents and teachers, and by the caring physicians."

Tuesday, December 19, 2006

When the "why?" isn't crucial...

I would like to point you to a brief article by Sally Satel in today's New York Times Science Section that mirrors my own sentiments about the usefullness of insight into how a maladaptive behavior, such as drug use or over-eating, might have originally started. Insisting on finding a cause can be an excuse for not working on changing a maladaptive behavior, and knowing a cause doesn't guarantee that behavior will change. There is no convincing data for the effectiveness of insight therapy, while there is such data for cognitive therapy - which trains one to note what isn't working when it starts up and choose to do something else. Satel says "It is time to retire the myth that insight is a prerequisite for change," and she offers two case studies:

"...the grail-like search for insight can backfire when it becomes a way for patients to avoid the hard work of change. This was my experience with Joe, a 24-year-old heroin addict. At every session, Joe would talk about his childhood relationship with his father, seeking new clues for how it damaged him and drove him to heroin...When I tried to change the topic to on-the-job stresses, which he linked to heroin craving, he said he’d rather “do psychotherapy.” Joe was forestalling the need to make practical changes. The many-layered drama with his dad doubled as an excuse for using heroin, absolving him of the responsibility to quit. When I proposed that possibility to him, he said, “Maybe you’re right.” But nothing really changed. He died of an accidental overdose a few months later."

"..insight has no guaranteed relationship to change. A colleague of mine treated a 45-year-old woman, Joan, who came for therapy because she hated her chunky body. Joan firmly believed that once she discovered The Reason for her overeating she would stop...After a few months, Joan told my colleague that her father had developed cancer the year she went off to college...“You know, I never made the connection until now,” she announced triumphantly, “but I started overeating when he began to waste away. It’s like I was trying to nourish him through myself.” ..A poignant metaphor, yes, but months later she hasn’t lost a pound."

An auditory-motor 'mirror" system is engaged by positive emotions.

More on mirror systems from Warren et al in Journal of Neuroscience. Edited clips from their paper:

Social interaction relies on the ability to react to communication signals. Although cortical sensory–motor "mirror" networks are thought to play a key role in visual aspects of primate communication, evidence for a similar generic role for auditory–motor interaction in primate nonverbal communication is lacking.

In this functional magnetic resonance imaging (fMRI) study, the authors investigated cortical regions responsive to both the perception of human vocalizations and the voluntary generation of facial expressions. In four auditory–perceptual conditions, subjects listened passively, without overt motor response, to nonverbal emotional vocalizations conveying two positive-valence emotions, amusement and triumph, and two negative-valence emotions, fear and disgust. Use of nonverbal, rather than verbal, vocalizations optimized recognizability of emotional content and avoided confounds of phonological and verbal content. In a facial movement condition, subjects performed voluntary smiling movements in the absence of auditory input. They hypothesized that cortical regions showing combined auditory–perceptual and motor responses would be located within premotor and motor cortical regions.

Figure legend: Brain regions demonstrating auditory–motor mirror responses. A shows regions (red) displaying a significant modulatory effect of emotion category on perceptual activation. B shows regions (light green) displaying significant activation during voluntary facial movements (motor > baseline). C, A masked inclusively in B shows regions (dark green) displaying both a significant modulatory effect of emotion category on perceptual activation and significant activation during voluntary facial movements.

Figure legend: Correlations with emotional valence and arousal in brain regions demonstrating auditory–motor mirror responses. Left, Regions (green) displaying both a significant modulatory effect of emotion category on perceptual activation and significant activation during voluntary facial movements as shown in the figure above. Right, Regions demonstrating a significant positive correlation between hemodynamic responses and emotional valence (red), emotional arousal (blue), or both (purple).

The authors demonstrated that a network of human premotor cortical regions activated during facial movement is also involved in auditory processing of affective nonverbal vocalizations. Within this auditory–motor mirror network, distinct functional subsystems respond preferentially to emotional valence and arousal properties of heard vocalizations. Positive emotional valence enhanced activation in a left posterior inferior frontal region involved in representation of prototypic actions, whereas increasing arousal enhanced activation in presupplementary motor area cortex involved in higher-order motor control. Their findings demonstrate that listening to nonverbal vocalizations can automatically engage preparation of responsive orofacial gestures, an effect that is greatest for positive-valence and high-arousal emotions. The automatic engagement of responsive orofacial gestures by emotional vocalizations suggests that auditory–motor interactions provide a fundamental mechanism for mirroring the emotional states of others during primate social behavior.

Motor facilitation by positive vocal emotions suggests a basic neural mechanism for establishing cohesive bonds within primate social groups.

Monday, December 18, 2006

Sleep deprivation slows the generation of new nerve cells

An interesting finding from Mirescu et al.... It is known that prolonged sleep deprivation is stressful, has adverse effects on cognitive performance and health, and raises corticosterone levels. Their work looks at new nerve cell formation (neurogenesis) in the rat hippocampus, which is central to cognitive performance. They show "that sleep deprivation inhibits adult neurogenesis at a time when circulating levels of corticosterone are elevated. Moreover, clamping levels of this hormone prevents the sleep deprivation-induced reduction of cell proliferation. The recovery of normal levels of adult neurogenesis after chronic sleep deprivation occurs over a 2-wk period and involves a temporary increase in new neuron formation. This compensatory increase is dissociated from glucocorticoid levels as well as from the restoration of normal sleep patterns. Collectively, these findings suggest that, although sleep deprivation inhibits adult neurogenesis by acting as a stressor, its compensatory aftereffects involve glucocorticoid-independent factors."

Sunday, December 17, 2006

The Meerkat wars and synchronicity

It is the year of the Meerkats. These engaging foot long denizens of the Kalahari desert show behaviors that mirror the best and the worst in our society (they steal, they fight, they cheat on their partners), and they have been the subjects of numerous television programs. Now, the Sunday NYTimes points out, just as we have had two Truman Capote movies within a short interval, two full length documentary films on Meekats are about to appear in competition, one from Discovery Films with Animal Planet, the other from BBC Films and the Weinstein company.

Saturday, December 16, 2006

The decline of civility and etiquette on the web.

Having been the recipient of some rather amazing invective comments on this blog (which I didn't permit to be published), not to mention that the majority of comments on the blog are now spam which I have to prevent from being posted, I have to pass on this piece in David Pogues weekly emailing associated with the circuits section of the NY Times.

Whatever Happened to Online Etiquette?

"Dear David, first off i would like to tell you that you are full of **** and did not research the zune enough to know your facts.

(Here follows a list of 'mistakes' made by Pogue)

Pogue then writes:

The deeper we sail into the new online world of communications, the sadder I get about its future. I'm OK with criticism, I'm fine with disagreement, I'm perfectly capable of handling angry mail. That's not the issue here (although my teenage correspondent above was, in fact, wrong about every single one of his points). I've even accepted personal attacks as part of the job. I'm a columnist; the heat comes with the kitchen. But what's really stunning is how hostile *ordinary* people are to each other online these days. Slashdot and are extremely popular sites for tech fans. Each discussion begins with the presentation of an article or Web page--and then opens up the floor for discussion.

Lately, an increasing number of the discussions devolve into name-calling and bickering. Someone might submit, say, this item to Digg:

685 diggs. "AWESOME astronomy poem." (posted by MetsFan 3 days ago) Twinkle, twinkle, little star, how I wonder what you are.
Up above the world so high, like a diamond in the sky,
Twinkle, twinkle, little star, how I wonder what you are.

Before long, the people's feedback begins, like this:

by baddude on 12/11/06
What's yr problem, moron. You already said it's a star, why would you then wonder what it is. Get a clue, or a life.
by neverland2 on 12/11/06
Dugg down as inaccurate. Stars do not twinkle. It's the shifting atmosphere that causes an apparent twinkle. Or were you stoned all through science class?
by mrobe on 12/11/06
yo neverland2--It's a poem, idiot. Nobody's claiming that stars twinkle. Ever heard of poetic license? Honestly, the intellectual level of you people is right up there with a gnat's.
...and so on.

What's worse is that the concentration of the nasty people increases as the civil ones get fed up and leave.

What's going on here?
My current theories:
* On the Internet, you're anonymous. Since you don't have to face the person you're dumping on, you don't see any reason to display courtesy.
* On the Internet, you're anonymous. You worry that your comments might get lost in the shuffle, so you lay it on thick to enhance your noticeability.
* The open toxicity is all part of the political climate. We've learned from the Red state-Blue state talking heads that open hostility can pass for meaningful conversation.
* Young people who spend lots of time online are, in essence, replacing in-person social interactions with these online exchanges. With so much less experience conversing in the real world, they haven't picked up on the value of treating people civilly. That is, they haven't yet hit the stage of life when getting things like friends, a spouse and a job depend on what kind of person you are.
* Many parents haven't been teaching social skills (or haven't been around to teach them) for years, but Web 2.0 is suddenly making it apparent for the first time. ("Web 2.0" describes sites like Digg and Slashdot, where the audience itself provides material for the Web site.)
I'd give just about anything to hear what 15-year-old Josh's parents would say if they knew how little respect he holds for adults (let alone the English language). Then again, maybe they wouldn't be surprised a bit.

The real shame, though, is that the kneejerk "everyone else is an idiot" tenor is poisoning the potential the Internet once had. People used to dream of a global village, where maybe we can work out our differences, where direct communication might make us realize that we have a lot in common after all, no matter where we live or what our beliefs.

But instead of finding common ground, we're finding new ways to spit on the other guy, to push them away. The Internet is making it easier to attack, not to embrace.

Maybe as the Internet becomes as predominant as air, somebody will realize that online behavior isn't just an afterthought. Maybe, along with HTML and how to gauge a Web site's credibility, schools and colleges will one day realize that there's something else to teach about the Internet: Civility 101.

A "mind reading" prosthesis for autistic people?

Another clip from the NYTimes Magazine "Ideas" issue:

"The Emotional-Social Intelligence Prosthesis, developed by Rana el Kaliouby and Rosalind Picard, consists of a small camera mounted on a cap or glasses that monitors a conversation partner’s facial expressions and feeds the data into a hand-held computer. Software tracks the movement of facial features and classifies them using a coding system developed by the psychologist Paul Ekman, which is then correlated with a second taxonomy of emotional states created by the Cambridge autism researcher (and Ali G cousin) Simon Baron-Cohen. Almost instantaneously, the computer crunches each raised eyebrow and pucker of the lips, giving a whispered verdict about how the person is feeling. (Another version of the device, meant to be used separately, points back at users, allowing them to better understand — and perhaps modify — the face they present to the world.)" (CLICK to enlarge image below).

Friday, December 15, 2006


I can't resist passing on David Haskell's piece in the NYTimes magazine "Ideas" issue in its entirety.

When approached to write an article about the homoerotic subtext of sports for Out magazine this spring, the journalist Mark Simpson feared the subject was old news. “There wasn’t much of a point,” he says, “since sport was already the new gay porn.” Indeed, with the publication of a Dolce & Gabbana underwear campaign featuring Italian soccer players glistening in a dank locker room, the phenomenon had gone well beyond subtext. All that was lacking was a name, and it didn’t take Simpson very long to invent it: sporno.

Sports, of course, have always celebrated physical form. What has changed, Simpson argues, is how we look at men. Thanks to what might be called the Abercrombie effect, the male body has become increasingly aestheticized — or “metrosexualized,” as Simpson would have it (he invented that term too) — and male imagery, particularly in fashion advertising, has become more overtly sensual. Considering that sports is visual, masculine and (like porn) geared mostly to men, Simpson was not surprised to find male athletes — even, or perhaps especially, heterosexual ones — grooming their physical image and “fetishizing themselves.”

The arrival of what Simpson calls “equal opportunity flirts” like the soccer players David Beckham and Freddie Ljungberg, who dabble in gay iconography and openly embrace their gay fans, lends sporno a celebrity cachet. (Simpson calls sporno stars like Ljungberg, whose physical assets are abundantly featured in Calvin Klein underwear ads, “young hustlers.”) Among professional sports organizations, the French national rugby team has pursued its sporno status most aggressively. The team’s annual calendars, Simpson notes, include photo shoots in which “there is no pretense that this is anything but hyperhomoerotic.” Indeed, some images are but a few soap bubbles away from pure pornography.

Psychological Neoteny

An interesting idea in the NYTimes Ideas issue from Bruce Charlton, a doctor and psychology professor at Newcastle University in Britain. What looks like immaturity — or in Charlton’s kinder terms, the “retention of youthful attitudes and behaviors into later adulthood” — is actually a valuable developmental characteristic, which he calls psychological neoteny. "So, the next time you see a mother of three head-banging to death metal or a 50-year-old man sporting a faux-hawk, don’t laugh...In a recent issue of Medical Hypotheses, a journal he edits, Charlton argues that unlike previous, more settled societies that could afford to honor a narrow and well-defined worldview (that is, a “mature” one), modern life is tumultuous and ever-changing. Accordingly, it rewards those who retain a certain plasticity of mind and personality. In a psychological sense, some contemporary individuals never actually become adults."

Thursday, December 14, 2006

Being hungry makes you smarter

Ghrelin is a hormone released by the gut when the absence of food is sensed. It is known to act on the hypothalamus in endocrine and metabolic regulation. Horvath's laboratory reports that making mice 'biochemically hungry' with ghrelin injections improves their performance in maze and other intelligence tests. From their abstract: "circulating ghrelin enters the hippocampus and binds to neurons of the hippocampal formation, where it promotes dendritic spine synapse formation and generation of long-term potentiation. These ghrelin-induced synaptic changes are paralleled by enhanced spatial learning and memory."

This suggests that a great way to prepare for an examination or demanding performance might be, according to Christopher Shea in the NYTimes comment on this work, "Go in mildly hungry, not carbo-loaded for endurance, and snack to maintain that edgy state. Such advice, applied on a national scale, might help save our schools. Since overweight kids have suppressed ghrelin levels, Horvath theorizes that perhaps the obesity epidemic has contributed to declining test scores and other American educational woes."

The Eyes of Honesty

Continuing with another nugget from last Sunday's NYTimes magazine... In the psychology department at Newcastle University, there is a coffee station where people can help themselves, so long as they leave money in the tray. Contributions were disappointing until a picture of a flower above the station was replaced by a picture of staring eyes. During weeks the eyes rather than the flowers were above the station, people contributed 2.7 times more for coffee and tea. Apparently even the feeling of being watched was enough to encourage people to behave more honestly. The paper describing this effect paper prompted a British police department in Birmingham to slap posters of eyes around the city as part of a campaign called “We’ve Got Our Eyes on Criminals.” The researchers are studying the campaign to see if the posters have an effect on things like car crime and vandalism.

Wednesday, December 13, 2006

Homophily on the web - serendipity as antidote?

Another item from last Sunday's NYTimes magazine "Ideas" issue relevant to how our human minds organize themselves.....

Homophily refers to our inexorable tendency to link up with one another in ways that confirm rather than test our core beliefs. This trend is accentuated on "web sites like Facebook and MySpace, which tend to bring birds of a feather together. Meanwhile, chains of recommendations (“if you liked . . . ”) on sites like Amazon reinforce our original preferences even as they claim to expand our horizons." Social software designers who are behind sites such as there are questioning "how much they should encourage homophily and how much they want to mix it up."

What kind of software design might encourage “serendipity” to counter focusing on the familiar? " One information-technology specialist described a feature he would add to Facebook called “the Stretch,” which would help students “find a group of people a little different” from themselves. Someone else brought up the online book cataloger LibraryThing’s UnSuggester, which identifies the book least likely to share a library with the book you mention."

Tuesday, December 12, 2006

Digital Maoism

Jaron Lanier has put an essay on that is most fascinating. His description of "Digital Maoism" is one of the important ideas of 2006 listed in last Sunday's New York Times Magazine.

"What we are witnessing today is the alarming rise of the fallacy of the infallible collective. Numerous elite organizations have been swept off their feet by the idea. They are inspired by the rise of the Wikipedia, by the wealth of Google, and by the rush of entrepreneurs to be the most Meta. Government agencies, top corporate planning departments, and major universities have all gotten the bug.

There is a pedagogical connection between the culture of Artificial Intelligence and the strange allure of anonymous collectivism online. Google's vast servers and the Wikipedia are both mentioned frequently as being the startup memory for Artificial Intelligences to come....George Dyson has wondered if such an entity already exists on the Net, perhaps perched within Google. My point here is not to argue about the existence of Metaphysical entities, but just to emphasize how premature and dangerous it is to lower the expectations we hold for individual human intellects.

The beauty of the Internet is that it connects people. The value is in the other people. If we start to believe that the Internet itself is an entity that has something to say, we're devaluing those people and making ourselves into idiots."

Steven Johnson's comment in the New York Times summary: "In the essay, Lanier grouped everything from his personal Wikipedia entry to “American Idol” under the umbrella of digital Maoism, and many of the responses to the article by assorted Internet luminaries observed that Lanier had elided important differences between these systems to make his point. The entirety of Wikipedia, for instance, is most certainly a collective undertaking, but many articles are written and edited by small numbers of individuals. Wikipedia may be not too far from the historical reality of Maoism itself: a system propagandized with the language of collectivism that was, in practice, actually run by a small power elite.

In any case, culture and technology are increasingly reliant on the hive mind — and whatever its faults, Lanier’s broadside helps us consider the consequences of this momentous development. A swarm of connected human minds is a fantastic resource for tracking down software bugs or discovering obscure gems on the Web. But if you want to come up with a good idea, or a sophisticated argument, or a work of art, you’re still better off going solo."

Brain imaging of intuition during perceptual discovery

Volz and von Cramon at the Max Planck Institute for Human Cognitive and BrainSciences in Leipzig, Germany, have done an interesting piece of work on imaging intuition, reported in the Journal of Cognitive Neuroscience. Here is their abstract:

"According to the Oxford English Dictionary, intuition is "the ability to understand or know something immediately, without conscious reasoning." Most people would agree that intuitive responses appear as ideas or feelings that subsequently guide our thoughts and behaviors. It is proposed that people continuously, without conscious attention, recognize patterns in the stream of sensations that impinge upon them. What exactly is being recognized is not clear yet, but we assume that people detect potential content based on only a few aspects of the input (i.e., the gist). The result is a vague perception of coherence which is not explicitly describable but instead embodied in a "gut feeling" or an initial guess, which subsequently biases thought and inquiry. To approach the nature of intuitive processes, we used functional magnetic resonance imaging when participants were working at a modified version of the Waterloo Gestalt Closure Task. Starting from our conceptualization that intuition involves an informed judgment in the context of discovery, we expected activation within the median orbito-frontal cortex (OFC), as this area receives input from all sensory modalities and has been shown to be crucially involved in emotionally driven decisions. Results from a direct contrast between intuitive and nonintuitive judgments, as well as from a parametric analysis, revealed the median OFC, the lateral portion of the amygdala, anterior insula, and ventral occipito-temporal regions to be activated."

The figure above indicates some of the task and stimuli conditions used. In the object condition, participants were presented with fragmented black-and-white line drawings of common objects which were subsequently fragmented with which differed in their potential to mask the drawing. In the nonobject condition, participants were presented with meaningless fragmented black-and-white line drawings. The upper left panel (A) shows an example of a coherent trial (violin), the upper right panel (B) an example of an incoherent trial. Stimuli were presented for 400 msec and participants had 2 sec to indicate whether the fragmented line drawing depicted a possible object (left response button) or an impossible object (right response button). Stimuli were neither presented repeatedly nor were images concurrently presented in different levels of fragmentation within one individual session. Participants were encouraged to base their decision on an "initial guess" whether or not the drawing was coherent.

This next figure shows MRI data. Group-averaged activations are shown on coronal, sagittal, and axial slices of an individual brain normalized and aligned to the Talairach stereotactic space. The upper left panel shows the imaging results of the direct contrast between trials that participants judged to be meaningful with trials that participants judged to be meaningless. The upper right panel shows the imaging results from the correlational analysis of the median OFC's (mOFC) time course. In the lower panel, imaging results from the parametric analysis are shown that used a performance-dependent regressor (i.e., the percentage of correct answers per level).

The data suggest that activation within the median orbito-frontal cortex reflects intuitive processing, while activation within ventral occipito-temporal regions reflects object recognition processes.

Monday, December 11, 2006

The Buddha and viscoelastic foam

Here from "The Monastery Store" is just the thing for all you sitting meditators who get sore backs, tailbones, and hip joints from attempting to sit for extended periods on classical meditation cushions containing natural fibers like kapok or buckwheat. They develop lumps that put even more stress on your spine. So, the Buddhist monks at Zen Mountain Monastery have come up with a viscoelastic foam cushion that always retains its original shape. (I still fail to understand why some meditation purists insist that a sitting posture unnatural and painful to most westerners is an essential element of the discipline. I find that a plain old chair is adequate for my limited excursions towards a more quiet mind.)

Guide to brain health

I received a review copy of "The Dana Guide to Brain Health", Dana Press, softcover, 2006, and I guess for the freebie should make a few comments. It is a cobbling together of contributions from 104 contributors edited by Floyd E. Bloom, M. Flint Beal, and David J. Kupfer, establishment guys with lots of credentials. William Saffire (Charman of the Dana Foundation board of directors), in the introduction says "This book is for amateurs like most of us...." It is meant to be the major home health reference on the brain. Such a source sounds good in principle, but I found myself wondering how a steelworker in Flint Michigan worried about his grandmother's stroke could deal with such a flatly written and encyclopedic effort. The huge volumne is not very approachable or friendly. He or she would pick up this book wanting perhaps to know something about strokes, and have to read though a long table of contents to figure out that Part IV "Conditions of the Brain and Nervous System", section 18, parts C59 and C60 had the word stroke in their title. To be
fair, if you get as far as the third section "How to read this book" it says you should look in the index. There you find a very long list of computer generated page and cross references. I'm not sure how our steelworker would deal with all the choices presented. If he or she simply entered "stroke" in google or any other search engine more engaging information from authoritative sources would immediately appear.

On the positive side, Part IV does present a comprehensive list of the basic ways that brains can go wrong, and this alone makes such a compliation worthwhile. Perhaps the volume will prove useful to those who are not computer literate (so why include a CD that adds absolutely nothing to the book?). I guess my take is that is book is a noble idea that in practice is not going to yield the benefits that its sponsors hope for.

Friday, December 08, 2006

Plagarism - how long does a phrase have to be?

I have to pass on some choice bits of an essay by Charles Isherwood in last Sunday's New York Times, occasioned by the flap over Ian McEwen having included some phrases on hospital life in his novel "Atonement" that were similar to those used by romance novelist Lucilla Andrews. (Letters in support of McEwan from heavyweights Margaret Atwood, Kazuo Ishiguro, John Updike, Zadie Smith, Martin Amis and Thomas Pychon have recently been published in the London Daily Telegraph. They point out that Shakespeare, Petrach, and Tolstoy also "stole" material from other sources.)

Isherwood wonders how long a phrase has to be before it becomes actionable: "Oh, dear! Looking back I must apologize for my use of the phrase “best-selling novel,” the very same words Mr. Cowell employed in describing “Atonement.” I am aghast. I should have said “Mr. McEwan’s novel ‘Atonement,’ which flew off the shelves like a massive flock of birds heading southward in the gloaming over the windswept moors.” Or something like that, to differentiate my description from Mr. Cowell’s. A grave mistake....Wait a minute. “Grave mistake” sounds eerily familiar. Egad! So does “eerily familiar.” I must get back to you in a few hours, after an exhaustive Google search that will doubtless allow me to credit any and all authors who have used those phrases."

"The string of scandals seems...a symptom of a shift in cultural attitudes toward the meaning and uses of personal experience. We are living in an age marked by a heightened sensitivity to the idea of one’s own life, and one’s own words, as a commodity with prospective commercial value. In earlier times, it was only writers and other artists who were expected to make profitable use of their everyday experience; the rest of us couldn’t hope to make a dime from the upheavals of existence...How things have changed. With the rise of so-called reality-based entertainment and the surging popularity of the memoir as a literary form, it now seems that everybody’s life is a yet-to-be-developed television property or a memoir waiting to spring from the laptop, uncontaminated by the greedy depredations of the artist. The rush for self-fulfillment and self-expression that characterized the “Me” decade of the 1970s has evolved into a desire for maximum self-exploitation and self-commercialization in these early years of the 21st century, which might be dubbed the “Buy Me” decade. We’d be fools to let someone make a profit off our own backs, and so as a culture we become exercised at the idea of a writer making money by making use of experience or words not entirely his own."

Isherwood quotes Malcolm Gladwell: “The ethics of plagiarism have turned into the narcissism of small differences,” he wrote. “Because journalism cannot own up to its heavily derivative nature, it must enforce originality on the level of the sentence.”

Isherwood: "It’s easy to see how such continued enforcement could create a climate antithetical to the kind of free ferment that artists need. Fiction writers are treasured precisely because they can transmute the unruly dross of daily experience — whether it is their own or that of a guy they once knew or a figure from tabloid headlines — into narratives that have a pleasing shape and pattern and give us insight into our lives. If our lives — and dare I say even our words — are to be our sovereign property, how many of us will really be able to make meaning from them that enriches the world?"

Thursday, December 07, 2006

Brain correlates of visual consciousness

Lau and Passingham report interesting experiments using "relative blindsight" that try to distinguish brain regions essential to visual performance from those involved also in subjective visual consciousness. Here are some edited clips from that work:

Blindsight refers to the phenomenon that, after a lesion to the primary visual cortex, a subject can exhibit above-chance performance in detecting or discriminating visual stimuli in a forced-choice setting, despite the lack of acknowledged consciousness of the stimuli. In some instances, blindsight subjects can perform at an impressively high level of accuracy (>80%) in the forced-choice task, even when the subjects believe that they are guessing. This potentially high level of performance makes blindsight an interesting case study for visual consciousness, because it indicates that it is consciousness, but not the basic capacity to process information, that is completely abolished.

Attempts to unequivocally demonstrate blindsight in normal observers have proved to be controversial, so instead of looking for a complete dissociation of performance and visual consciousness as in the case of blindsight, the authors set out to look for a relative difference ("relative blindsight") in the level of visual consciousness in two conditions in which performance levels are matched. These conditions can be created by using a psychophysical paradigm based on metacontrast masking, shown in Figure 1. In metacontrast masking, a figure that overlaps with the contour of the target is presented after the target. Discrimination performance for a target stimulus decreases and then increases as the temporal distance between the target and a metacontrast mask increases gradually; this distance is referred to as stimulus onset asynchrony (SOA).

Fig. 1. Visual discrimination task with metacontrast masking measured to demonstrate the phenomenon of relative blindsight. The stimuli were presented on a black background. The mask overlaps with part of the contour of the target without leaving gaps or overlapping with the target spatially. After the presentation of the target and the mask, the participants were first asked to decide whether a diamond or a square was presented. Then they had to indicate whether they actually saw the target or whether they simply guessed the answer. Shown in the brackets are the durations of each stimulus.

For the SOA points at 33 and 100 ms, the performance levels (i.e., accuracy rates for the square vs. diamond discrimination) were very similar. However, the subjective judgment of consciousness differed in that at the earlier SOA point volunteers were more likely to claim to have just guessed the answers. Thus the subjective level of consciousness can differ in the absence of a difference of performance levels.

Fig. 2 Activity in the mid-DLPFC reflects visual consciousness (long SOA > short SOA). The activity in this area is higher in the long SOA condition than in the short SOA condition, despite the fact that the two conditions did not yield different discrimination accuracy. There were, however, more trials during which the stimuli were classified by the participants as consciously seen in the long SOA condition than in the short SOA condition. This area was the only one found to be activated in this comparison; parietal activity did not differ significantly even at liberal thresholds.

To identify the brain areas where activity reflected discrimination performance in general, they also analyzed the fMRI results by comparing correct and incorrect trials, combining short SOA and long SOA trials. They found widespread activations in the ventral prefrontal, premotor, parietal, and temporal cortices. The pattern of these activations resembled that in a so-called frontal–parietal network, typically reported in previous studies of visual consciousness. VLPFC, ventrolateral prefrontal cortex; IPS, intraparietal sulcus; MTG, middle temporal gyrus.

Fig. 3 Activations reflecting performance in general (correct trials > incorrect trials). Activations were found in these areas when correct trials were compared against incorrect trials, combining all trials of both SOA conditions.

Although activity in the parietal cortex was found to be related to performance in general, it did not significantly differ between the conditions in which the subjective criteria for conscious perception differed. ...This seems to differ from the results of many previous NCC studies, which have found parietal activity to be as significant as the prefrontal activity, if not more so. The authors argue that it is possible that some of those previously reported activations in the parietal cortex may reflect performance, given that a difference in consciousness level is typically associated with a difference in performance. The potential role of the prefrontal cortex might be further clarified by giving the task used in the present study to patients with lesions that include the mid-DPLFC. Such a study would help contribute further to our understanding of the role of the prefrontal cortex in subjective conscious perception.

Wednesday, December 06, 2006

How the aging brain compensates to preserve language functions

Wingfield and Grossman report in Journal of Neurophysiology their studies of how language comprehension typically remains well preserved in normal aging, in spite of the fact that aging brings with it declines in sensory function, both in vision and in hearing, as well as a general slowing in a variety of perceptual and cognitive operations. They start by reviewing language processing regions of the brain that have been identified both through studies of brain damage and neuroimaging. This figure shows some relevant areas:

Figure 1 description: Within a broad perisylvian region, deficits in language production have been shown to be associated with damage to the ventral inferior frontal cortex (vIFC), which includes Broca's area, and deficits in language comprehension associated with damage to the posterior lateral temporal cortex (PLTC), a part of which is commonly referred to as Wernicke's area. This early picture was completed by discovery of a white-matter tract, the arcuate fasciculus, connecting these two regions. The aphasic syndromes of Broca's aphasia, Wernicke's aphasia, and conduction aphasia were thus neatly accounted for by damage to, or disconnections between, these centers and pathways. These three components of the core sentence processing region colored are shown in blue, with the arcuate fasciculus represented by the connecting blue double-headed arrow. As first implied by the effects of focal brain damage, this core network for sentence processing has been confirmed and more exactly specified by neuroimaging studies in healthy adults. The resource network involves at least several frontal cortical regions and extends to include right hemisphere structures as well as subcortical structures. The left hemisphere structures associated with the recruitment of working-memory and executive resources include dorsolateral prefrontal cortex (dlPFC) and dorsal portion of left inferior frontal cortex (dIFC). Regions in the right hemisphere include PLTC and dIFC. These regions are shown in red.

Winglield and Grossman proceed to present data from their own and other studies that support a compensation hypothesis to explain how declining cell numbers and cortical volumes in these language areas are compensated for by recruitment of other areas. A number of imaging studies contrasting performance by healthy young and older adults have shown a major difference in observed patterns of neural activation when young and older adults are asked to perform the same cognitive task. In general, there is a shift from more focal activation in young adults to more widespread patterns of activation in older adults. This pattern has been observed in a number of cognitive domains, from encoding pictures to studies of episodic memory.

Activity of the core sentence processing network (blue in the above figure) and the resource network (red) during complex sentence comprehension was followed and performance level measured in a number of experiments.

Figure 2 shows regional brain activation contrasts during sentence comprehension for young adults, elderly good comprehenders, and elderly poor comprehenders. A: areas activated by young adults to a greater degree than the elderly good comprehenders. B: areas activated by elderly good comprehenders to a greater degree than young adults. C: areas activated to a greater degree by elderly good comprehenders than by elderly poor comprehenders. D: areas activated to a greater degree by elderly poor comprehenders than by elderly good comprehenders.

In A, young adults were producing a significantly greater degree of activation than the older adults in the posterolateral temporal-parietal cortex in the left hemisphere. This region is thought to support a short-term auditory-phonological buffer that retains information transiently during the course of processing. B. the compensation hypothesis would lead one to expect to see the successful older adults recruit other brain regions to maintain their successful performance. This contrast can be revealed by subtracting the activation levels in the young adults from the older adults' activations. The consequences of this subtraction are shown in the two brain renderings in B, where one sees these successful older adults showing significant upregulation in two areas. One of these is increased activity in the dorsal portion of left inferior frontal cortex. This area is thought to be important for maintaining and rehearsing stored verbal information in working memory. Successful older adults also showed additional activation in the right posterolateral temporal-parietal region. The data illustrate the involvement of a network of cortical areas upregulated in support of sentence processing beyond the left perisylvian core sentence-processing area. In particular, the network upregulates by augmenting working-memory resources needed to support sentence processing.

These studies offer a window on the strategic recruitment of critical brain regions by older adults in response to otherwise limited working-memory resources not seen during sentence comprehension in young adults. They show that older adults augment regional brain activation within the language-processing system both spatially and temporally to help compensate for age-related neuronal changes.

Tuesday, December 05, 2006

Terror Management and Religious Belief

Jonas and Fisher (J. Pers. Soc. Psychol. 91, 553; 2006) conduct three different studies that find that people emphasizing intrinsic religious beliefs (emphasizing meaning and value) are more buffered against thoughts of mortality when reminded of dying (news of terrorist attacks) than people who emphasize extrinsic religios beliefs (searching for safety and solice).

Their complete abstract: "Terror management theory suggests that people cope with awareness of death by investing in some kind of literal or symbolic immortality. Given the centrality of death transcendence beliefs in most religions, the authors hypothesized that religious beliefs play a protective role in managing terror of death. The authors report three studies suggesting that affirming intrinsic religiousness reduces both death-thought accessibility following mortality salience and the use of terror management defenses with regard to a secular belief system. Study 1 showed that after a naturally occurring reminder of mortality, people who scored high on intrinsic religiousness did not react with worldview defense, whereas people low on intrinsic religiousness did. Study 2 specified that intrinsic religious belief mitigated worldview defense only if participants had the opportunity to affirm their religious beliefs. Study 3 illustrated that affirmation of religious belief decreased death-thought accessibility following mortality salience only for those participants who scored high on the intrinsic religiousness scale. Taken as a whole, these results suggest that only those people who are intrinsically vested in their religion derive terror management benefits from religious beliefs."

Monday, December 04, 2006

How to define happiness....?

Excerpting from an article by Reichhardt (Nature 444, 418-419; 23 November 2006) and an editorial (pp 401-402) in the same issue of nature:
Is happiness a single emotion or a personality trait? A physical state, with characteristic brain-wave patterns and biomarkers? Is it simply the absence of unhappiness, or something else? ... This new science has yet to provide a compelling account of how happiness is created. Instead, for obvious methodological reasons, it concentrates on what it correlates with. But it is not clear that changing those correlates by dictat would necessarily produce the desired effect. People may be happy spending time with their children, but forcing parents to spend more time this way would not necessarily overjoy everyone involved. Expressing gratitude makes people happier; a politeness police, probably, would not.

There is further debate as to whether trying to do something about people's happiness is feasible in principle. Some researchers favour the idea that people have a 'hedonic setpoint' that stays remarkably constant in the face of bouquets and brickbats. Such a setpoint need not in principle be unalterable, but its alteration might require an approach with a pharmacological component, raising the problem that one of the things we value about happiness is its authenticity. Another is its autonomy. Governments may guarantee citizens freedom in their pursuit of happiness, but we bridle against the idea of its ever being enforced.

Carol Ryff (University of Wisconsin) is responsible for perhaps the most ambitious well-being research project on happiness ever conducted, the Midlife in the United States, or MIDUS II, study...Ryff hopes to find out whether well-being and ill-being (depression and so on) have distinct biological correlates, or whether they are at opposite ends of the same psychological spectrum. One of her previous studies on a group of 135 older women assessed on biomarkers such as cortisol and waist–hip ratio, suggested that the biological correlates of well-being and ill-being are largely distinctive6. That's one issue MIDUS II will investigate more fully.

Ryff likes to distinguish between hedonic well-being (moods and feelings) and eudaimonic well-being, which is more concerned with factors such as having purpose in life, continued personal growth and development, and good relationships with others. In fact, Ryff rarely uses the term 'happiness'. Perhaps that's because the more scientists learn, the less precise the term has become.

That's roughly where the science of happiness stands right now — still wrestling with its own terminology. Ryff has little time for the fluffier aspects of positive psychology, which she dismisses as "a lot of PR". But one thing she and other well-being researchers can agree on is the nature of the question, "We're going after it in a serious way," she says. "In the final analysis, it's an empirical question."

(By the way, the Smiley Face is made from nanotubes of DNA; see Rothermund, Nature 440, 297–302; 2006)

Friday, December 01, 2006

Just thinking about money changes you.

"The Psychological Consequences of Money" by Vohs et. al. in the Nov 17 issue of Science and an accompanying commentary by Burgoyne and Lee report on nine different experiments that show "that even quite trivial exposure to the idea of money (for example, unscrambling phrases about money or reading an essay about money aloud) changes the goals and behavior of test subjects (none of the student participants in the study realized that it was about money) brings about a self-sufficient orientation in which people prefer to be free of dependency and dependents. Reminders of money, relative to nonmoney reminders, led to reduced requests for help and reduced helpfulness toward others. Relative to participants primed with neutral concepts, participants primed with money preferred to play alone, work alone, and put more physical distance between themselves and a new acquaintance...The self-sufficient pattern helps explain why people view money as both the greatest good and evil. As countries and cultures developed, money may have allowed people to acquire goods and services that enabled the pursuit of cherished goals, which in turn diminished reliance on friends and family. In this way, money enhanced individualism but diminished communal motivations, an effect that is still apparent in people's responses to money today."

Thursday, November 30, 2006

Predictive Codes for Forthcoming Perception in the Frontal Cortex

Incoming sensory information is often ambiguous, and the brain has to make decisions during perception. "Predictive coding" proposes that the brain resolves perceptual ambiguity by anticipating the forthcoming sensory environment, generating a template against which to match observed sensory evidence. Summerfield et al have observed a neural representation of predicted perception in the medial frontal cortex, while human subjects decided whether visual objects were faces or not. Perceptual decisions about faces were associated with an increase in top-down connectivity from the frontal cortex to face-sensitive visual areas, consistent with the matching of predicted and observed evidence for the presence of faces.

Figure: A simple dynamic causal model with hierarchically ordered bidirectional connections between vMFC (ventromedial frontal cortex), amygdala, FFA (fusiform face area), and IOG (inferior occipital gyrus). Face and nonface stimuli were modeled as inputs to IOG, and face sets as inputs to vMFC.

Wednesday, November 29, 2006

For Some People, Intimacy Is Toxic.... The Virtues of Solitude

I've been wanting to mention a brief essay in the Nov. 21 New York Times by psychotherapist Richard Friedman that describes a patient who defied the "article of faith among psychotherapists that an intimate human relationship is good for you." A software engineer pushed by family and constant therapy to be more social, he finally became engaged to a woman, and then came to Friedman after a suicide attempt, treatment for depression, and breaking from the engagement. Friedman found "He wasn't depressed or unhappy at all. He enjoyed his work as a software engineer immensely, and he was obviously successful at it. It was just that human relationships were not that important to him; in fact, he found them stressful...intimacy, it seems, is not for everyone."

It hardly seems surprising that genetic and developmental reasons lead some humans to be extremely affiliative, while others can be quite content in solitude. "Solitude: a return to the self" is in fact the title of an excellent and thoughtful book by Oxford University psychiatrist Anthony Storr. He notes: "The current emphasis upon intimate interpersonal relationships as the touchstone of health and happiness is a comparatively recent phenomenon. Earlier generations would not have rated human relationships so highly; believing, perhaps that the daily round, the common task, should furnish all we need to ask.." Storr provides an interesting history of how mental health came to be equated with the quality and quality of social relationships, and argues that a preference for solitude, self understanding, and a more muted social presence can be also be compatible with robust mental health.

Tuesday, November 28, 2006

The latest on Resveratrol enhancing health and longevity

Pretty soon we'll all be chowing down on grape skin extracts. I actually tried this stuff several years ago and thought it increased my joint I stopped. Many scientists recommed caution before plunging into yet another food supplement fad.

Anyway, here is the latest bit from a Nature article:

"Resveratrol (3,5,4'-trihydroxystilbene) extends the lifespan of diverse species including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster. In these organisms, lifespan extension is dependent on Sir2, a conserved deacetylase proposed to underlie the beneficial effects of caloric restriction. Here we show that resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival. Resveratrol produces [biochemical] changes associated with longer lifespan......"

Monday, November 27, 2006

How we make our visual world appear to be constant.

At the same time that our brains command a body movement, they also generate an expection of the sensory outcome of that movement that is checked against the actual results. The nerve pathways underlying this elegant control system have not been well understood. Now comes a nice piece of work from Sommer and Wurtz. In their own words: "Each of our movements activates our own sensory receptors, and therefore keeping track of self-movement is a necessary part of analysing sensory input. One way in which the brain keeps track of self-movement is by monitoring an internal copy, or corollary discharge, of motor commands. This concept could explain why we perceive a stable visual world despite our frequent quick, or saccadic, eye movements: corollary discharge about each saccade would permit the visual system to ignore saccade-induced visual changes. The critical missing link has been the connection between corollary discharge and visual processing. Here we show that such a link is formed by a corollary discharge from the thalamus that targets the frontal cortex. In the thalamus, neurons in the mediodorsal nucleus relay a corollary discharge of saccades from the midbrain superior colliculus to the cortical frontal eye field. In the frontal eye field, neurons use corollary discharge to shift their visual receptive fields spatially before saccades...These experiments establish the first link between corollary discharge and visual processing, delineate a brain circuit that is well suited for mediating visual stability, and provide a framework for studying corollary discharge in other sensory systems."

Thursday, November 23, 2006

Making pain worse - basis of the Nocebo effect

In the nocebo effect - the opposite of the placebo effect - expectations of symptom worsening play a crucial role. Most of our knowledge about the analgesic placebo effect comes from the field of pain. It has been associated with decreased activity in the anterior cingulate and is diminished by antagonists of opiodergic peptide systems. The worsening of pain by exppectation has not been studied as thoroughly. Benedetti et al have now used a neuropharmacological approach to show that the hyperalgesic nocebo effect is associated with the activation of the CCKergic brain peptide system, as well as activation of the hypothalamic–pituitary–adrenal axis activated by stress. Thus the the analgesic placebo/hyperalgesic nocebo phenomenon may involve the opposite activation of endogenous opioidergic and CCKergic systems.

Wednesday, November 22, 2006

The Case Against Faith .. and what's the alternative

I've mentioned Sam Harris in previous posts. He is the author of two New York Times best sellers: "Letter to a Christian Nation" and "The End of Faith." Below I'm passing on a concise essay he recently wrote for Newsweek magazine.

What is absent from his critique of religion is a positive scientifically grounded alternative that meets the same human needs for solice and community that religion sometimes serves. Relevant to this is the recent NYTimes article "A Free-for-All on Science and Religion." which describes a meeting held at th Salk Institute in San Diego which "began to resemble the founding convention for a political party built on a single plank: in a world dangerously charged with ideology, science needs to take on an evangelical role, vying with religion as teller of the greatest story ever told."

The Harris essay:

"Despite a full century of scientific insights attesting to the antiquity of life and the greater antiquity of the Earth, more than half the American population believes that the entire cosmos was created 6,000 years ago. This is, incidentally, about a thousand years after the Sumerians invented glue. Those with the power to elect presidents and congressmen—and many who themselves get elected—believe that dinosaurs lived two by two upon Noah's Ark, that light from distant galaxies was created en route to the Earth and that the first members of our species were fashioned out of dirt and divine breath, in a garden with a talking snake, by the hand of an invisible God.

This is embarrassing. But add to this comedy of false certainties the fact that 44 percent of Americans are confident that Jesus will return to Earth sometime in the next 50 years, and you will glimpse the terrible liability of this sort of thinking. Given the most common interpretation of Biblical prophecy, it is not an exaggeration to say that nearly half the American population is eagerly anticipating the end of the world. It should be clear that this faith-based nihilism provides its adherents with absolutely no incentive to build a sustainable civilization—economically, environmentally or geopolitically. Some of these people are lunatics, of course, but they are not the lunatic fringe. We are talking about the explicit views of Christian ministers who have congregations numbering in the tens of thousands. These are some of the most influential, politically connected and well-funded people in our society.

It is, of course, taboo to criticize a person's religious beliefs. The problem, however, is that much of what people believe in the name of religion is intrinsically divisive, unreasonable and incompatible with genuine morality. One of the worst things about religion is that it tends to separate questions of right and wrong from the living reality of human and animal suffering. Consequently, religious people will devote immense energy to so-called moral problems—such as gay marriage—where no real suffering is at issue, and they will happily contribute to the surplus of human misery if it serves their religious beliefs.

A case in point: embryonic-stem-cell research is one of the most promising developments in the last century of medicine. It could offer therapeutic breakthroughs for every human ailment (for the simple reason that stem cells can become any tissue in the human body), including diabetes, Parkinson's disease, severe burns, etc. In July, President George W. Bush used his first veto to deny federal funding to this research. He did this on the basis of his religious faith. Like millions of other Americans, President Bush believes that "human life starts at the moment of conception." Specifically, he believes that there is a soul in every 3-day-old human embryo, and the interests of one soul—the soul of a little girl with burns over 75 percent of her body, for instance—cannot trump the interests of another soul, even if that soul happens to live inside a petri dish. Here, as ever, religious dogmatism impedes genuine wisdom and compassion.

A 3-day-old human embryo is a collection of 150 cells called a blastocyst. There are, for the sake of comparison, more than 100,000 cells in the brain of a fly. The embryos that are destroyed in stem-cell research do not have brains, or even neurons. Consequently, there is no reason to believe they can suffer their destruction in any way at all. The truth is that President Bush's unjustified religious beliefs about the human soul are, at this very moment, prolonging the scarcely endurable misery of tens of millions of human beings.

Given our status as a superpower, our material wealth and the continuous advancements in our technology, it seems safe to say that the president of the United States has more power and responsibility than any person in history. It is worth noting, therefore, that we have elected a president who seems to imagine that whenever he closes his eyes in the Oval Office—wondering whether to go to war or not to go to war, for instance—his intuitions have been vetted by the Creator of the universe. Speaking to a small group of supporters in 1999, Bush reportedly said, "I believe God wants me to be president." Believing that God has delivered you unto the presidency really seems to entail the belief that you cannot make any catastrophic mistakes while in office. One question we might want to collectively ponder in the future: do we really want to hand the tiller of civilization to a person who thinks this way?

Religion is the one area of our discourse in which people are systematically protected from the demand to give good evidence and valid arguments in defense of their strongly held beliefs. And yet these beliefs regularly determine what they live for, what they will die for and—all too often—what they will kill for. Consequently, we are living in a world in which millions of grown men and women can rationalize the violent sacrifice of their own children by recourse to fairy tales. We are living in a world in which millions of Muslims believe that there is nothing better than to be killed in defense of Islam. We are living in a world in which millions of Christians hope to soon be raptured into the stratosphere by Jesus so that they can safely enjoy a sacred genocide that will inaugurate the end of human history. In a world brimming with increasingly destructive technology, our infatuation with religious myths now poses a tremendous danger. And it is not a danger for which more religious faith is a remedy."

Tuesday, November 21, 2006

An inherited primate baseline for spatial cognition.

Haun et al report some interesting experiments that suggest that human infants inherit many of the same cognitive preferences and biases as our primate cousins but then go on to build cognitive structures that may diverge in various ways from this primate base under the influence of language and culture. Their experiments examine the spatial frames of reference (FoRs) used by children and adults in a Dutch village and a Khoisan hunter-gatherer community in Namibia, as well as by representative of the three major great ape genera (orangutans, gorillas, and chimpanzees; using animals in the Leipzig Zoo). Extensive field research in over 20 languages reveal that just three FoRs seem to be used. Some languages mainly use a relative EGOCENTRIC, viewpoint-dependent FoR with terms like front, back, left, and right: "The ball is to the left of the tree" (from my point of view). Some languages mainly use an intrinsic OBJECT CENTERED relational FoR, which makes reference to faceted objects, e.g., "The ball is at the front of the house." Some languages mainly use a third, so-called absolute GEOCENTRIC FoR in which linguistic descriptions use cardinal-direction type systems such as our North, South, East, and West: "The hot water is in the northern tap." Although most languages have several FoRs in their repertoire, egocentric relative constructions are predominant in European languages, whereas the geocentric absolute FoR is dominant, for example, in several indigenous languages of Australia, Papua New Guinea, Mexico, Nepal, and south West Africa.

Here is the experimental setup used for Dutch and Khosian children and adults:

Legend ((Click figure to enlarge)) Experimental setup in two consecutive example trials. Ten exactly identical cups were placed on two tables (five cups on each table). Participants were watching while a target was hidden under the cup depicted as white (HIDING). Then the participants moved to the other table and indicated where they thought a second target might be hidden (FINDING). The three differently striped cups show the different contingencies rewarded in the three consecutive blocks of trials.

Both children and adults were more accurate (made fewer errors) and were faster to learn the finding pattern that matched the FoR dominant in their language (egocentric for the Dutch, geocentric for the Khosian). This correlation is fully robust by age 8 and persists into adulthood.

Because of the shorter attention span of the ape participants, and because of their known limitations with respect to abstract reasoning, experimental conditions were simplified, so that three instead of five cups were on each table. As a result, the object-centered and geocentric conditions were collapsed. The three identical cups in a straight line offer only two alternative strategies: The egocentric one and an allocentric one, which could be based on either object-centered or geocentric cues. Experiments precisely analogous to the human experiment ware done, but more clear results were obtained in further experiments when rewards (food in one cup) were incorporated.

The bottom line, according to the authors: "All great ape genera prefer to process spatial relations based on environmental cues and not self. The standard methods of comparative cognition thus suggest a common phylogenetic inheritance of a preference for allocentric spatial strategies from the ancestor shared by all four existing genera of Hominidae (Pongo, Gorilla, Pan, and Homo). Based on this result, we argue that, at least for small-scale spatial relations, the inherited cognitive mode of operation is not, as argued by Kant and others, egocentric but preferably deploys environmental cues as common reference between objects."

Monday, November 20, 2006

Enhancing Cognition after Stress with Gene Therapy

This is the title of an article from Sapolsky's laboratory. Sapolsky is an amazing off the wall guy. His book "Why Zebras Don't Get Ulcers" is a classic on the biology of stress. He also has written fascinating stuff on aging. In this article he and his coworkers describe a clever trick for diminishing the impairment of memory acquisition and retrieval caused by the adrenal steroid hormones secreted during stress (glucocorticoids, or GCs). Estrogen, known to enhance spatial memory performance, can block the deleterious effects of GCs. The laboratory constructed a chimeric gene ("ER/GR") containing the hormone-binding domain of the GC receptor and the DNA binding domain of the estrogen receptor; as a result, ER/GR transduces deleterious GC signals into beneficial estrogenic ones. A deleterious effect of immobilization stress on spatial memory acquisition and retrieval in male rats was blocked by hippocampal expression of the ER/GR transgene. ER/GR also blocks the suppressive effects of GCs on expression of brain-derived neurotrophic factor (BDNF), a growth factor central to hippocampal-dependent cognition and plasticity, instead producing an estrogenic increase in BDNF expression. These experiments don't mean we are going to be able to use gene therapy to reverse the effects of stress on memory in humans any time soon. The clever tricks for getting transgenes into specific parts of rat brains don't yet exist for us humans.