This blog reports new ideas and work on mind, brain, behavior, psychology, and politics - as well as random curious stuff. (Try the Dynamic Views at top of right column.)
Thursday, October 30, 2008
Fair and Balanced - measuring media bias
One hears charges from both left and right about media bias, with FOX News frequently cited as the most extreme case. Tim Groeling has done interesting work to objectively measure the bias shown by television media, in a paper (PDF here) to be published in the December issue of Presidential Studies Quarterly. He simply collected the in-house presidential approval polling by ABC, CBS, NBC and FOX News and compared these with the actual broadcasts of such polls on evening news shows from 1997 to early 2008. As an example, CBS was 35 percent less likely to report a five-point drop in approval for Bill Clinton than a similar rise in approval and was 33 percent more likely to report a five-point drop than a rise for George W. Bush. FOX News was 67 percent less likely to report a rise in approval for Clinton than a decrease and 36 percent more likely to report an increase rather than a decrease for Bush.
Wednesday, October 29, 2008
Watching the amygdala signal the good and the bad
An interesting piece in Jour. of Neuoscience by Belova et al., in which recordings from single cells in the monkey amygdala indicate their division into those that track either positive state or negative states:
As an organism interacts with the world, how good or bad things are at the moment, the value of the current state of the organism, is an important parameter that is likely to be encoded in the brain. As the environment changes and new stimuli appear, estimates of state value must be updated to support appropriate responses and learning. Indeed, many models of reinforcement learning posit representations of state value. We examined how the brain mediates this process by recording amygdala neural activity while monkeys performed a trace-conditioning task requiring fixation. The presentation of different stimuli induced state transitions; these stimuli included unconditioned stimuli (USs) (liquid rewards and aversive air puffs), newly learned reinforcement-predictive visual stimuli [conditioned stimuli (CSs)], and familiar stimuli long associated with reinforcement [fixation point (FP)]. The FP had a positive value to monkeys, because they chose to foveate it to initiate trials. Different populations of amygdala neurons tracked the positive or negative value of the current state, regardless of whether state transitions were caused by the FP, CSs, or USs. Positive value-coding neurons increased their firing during the fixation interval and fired more strongly after rewarded CSs and rewards than after punished CSs and air puffs. Negative value-coding neurons did the opposite, decreasing their firing during the fixation interval and firing more strongly after punished CSs and air puffs than after rewarded CSs and rewards. This representation of state value could underlie how the amygdala helps coordinate cognitive, emotional, and behavioral responses depending on the value of one's state.
Blog Categories:
animal behavior,
emotion,
fear/anxiety/stress,
happiness,
motivation/reward
Happiness and the 'prosperoscope'
The random samples section of Science Magazine discusses the latest prosperity or 'happiness index' report of the Legatum Institute:
The results are in: Australia is the most prosperous country in the world; Yemen drags at the bottom of the list. But it's not just wealth that makes a country prosperous, according to the 2008 prosperity index, also known as the "happiness index," published last week by the Legatum Institute (LI) in Dubai (see www.prosperity.com). The institute based its rankings on surveys of economic competitiveness and comparative livability from 140 countries, including factors such as capital investment and the degree of social equality.You might enjoy playing with the 'prosperiscope' on the site.
This year, for the first time, countries' environmental efforts counted toward their scores, says LI Senior Vice President William Inboden. The institute selected an objective measurement--the ratio of developed land to land remaining in its natural state in each country--and added questions about how respondents felt about their country's environmental policies. Depending on a country's wealth, the environmental measures could count for as much as 4% of a country's prosperity score. Although Australia was the most prosperous country overall, New Zealand topped the environmental measures. The most environmentally unhappy people were Ukrainians, who particularly dislike their air quality.
"The Legatum Prosperiscope™ is a powerful interactive online tool that allows users to customise analyses across 104 countries using 22 different factors. Users can also compare countries against each other to identify their relative strengths and weaknesses. Follow the simple steps on the right to start using the Prosperiscope."
Tuesday, October 28, 2008
Instinctual math
Natalie Angier does an interesting article on our instinctual intuitive math versus our more analytical learned number crunching, and the relationship between them. Apparently our evolutionarily endowed sense of approximation is related to how good we are at formal math. The article contains a neat interactive demonstration of our non verbal intuitive math abilities.
Brain imaging studies have traced the approximate number sense to a specific neural structure called the intraparietal sulcus, which also helps assess features like an object’s magnitude and distance. Symbolic math, by contrast, operates along a more widely distributed circuitry, activating many of the prefrontal regions of the brain that we associate with being human. Somewhere, local and global must be hooked up to a party line.
...open questions include how malleable our inborn number sense may be, whether it can be improved with training, and whether those improvements would pay off in a greater appetite and aptitude for math. If children start training with the flashing dot game at age 4, will they be supernumerate by middle school?
Views of the presidential candidates on science
Here is the PDF from Science Magazine.
Monday, October 27, 2008
Poulenc Novelette in C major for a Monday morning
Recorded 10/25/08 on the Steinway B in my home on Twin Valley Road in Middleton, Wisconsin.
Experiencing physical warmth promotes interpersonal warmth
Here is the abstract of the article by Williams and Bargh which has the title of this post:
"Warmth" is the most powerful personality trait in social judgment, and attachment theorists have stressed the importance of warm physical contact with caregivers during infancy for healthy relationships in adulthood. Intriguingly, recent research in humans points to the involvement of the insula in the processing of both physical temperature and interpersonal warmth (trust) information. Accordingly, we hypothesized that experiences of physical warmth (or coldness) would increase feelings of interpersonal warmth (or coldness), without the person's awareness of this influence. In study 1, participants who briefly held a cup of hot (versus iced) coffee judged a target person as having a "warmer" personality (generous, caring); in study 2, participants holding a hot (versus cold) therapeutic pad were more likely to choose a gift for a friend instead of for themselves.
Embodied cognition, a cold stare makes you feel cold.
I show below the abstract from Zhong and Leonardelli, followed by more explanation from an article by Benedict Carey.
Metaphors such as icy stare depict social exclusion using cold-related concepts; they are not to be taken literally and certainly do not imply reduced temperature. Two experiments, however, revealed that social exclusion literally feels cold. Experiment 1 found that participants who recalled a social exclusion experience gave lower estimates of room temperature than did participants who recalled an inclusion experience. In Experiment 2, social exclusion was directly induced through an on-line virtual interaction, and participants who were excluded reported greater desire for warm food and drink than did participants who were included. These findings are consistent with the embodied view of cognition and support the notion that social perception involves physical and perceptual content. The psychological experience of coldness not only aids understanding of social interaction, but also is an integral part of the experience of social exclusion.More detail on the two experiments:
In one, they split 65 students into two groups, instructing those in one to recall a time when they felt socially rejected, and those in the other to summon a memory of social acceptance.
Many of the students were recent immigrants and had fresh memories of being isolated in the dorms, left behind while roommates went out, Dr. Zhong said.
The researchers then had each of the participants estimate the temperature in the lab room. The students who had recalled being excluded estimated the temperature to be, on average, 5 degrees Fahrenheit lower than the others.
In the second experiment, the researchers had 52 students come into the lab and play a computer game, one at a time. The students “threw” a ball back and forth with three other figures on the computer screen that — so the participants thought — represented other students playing from remote locations.
In fact a computer program was running the game, and it excluded half the study participants, throwing them the virtual ball a couple of times in the beginning, then ignoring them altogether. The other group of students in the study were included in the virtual game of catch.
After playing the game, the participants in this study then rated their preferences for a variety of foods and drinks, including hot soup, coffee, an apple and crackers. Those who had been isolated in the computer game showed a strong preference for the soup and coffee over the other items; the included students had no such preference.
Blog Categories:
embodied cognition,
emotion,
psychology,
social cognition
Sunday, October 26, 2008
Drinking alone, with "friends" on Facebook
I'm struck by how very little I know about the ~10,000 visitors that Quantcast tells me come to Deric's MindBlog each month. Thus this essay in the "Lives" section of today's New York Times Magazine struck a chord with me.
Blog Categories:
culture/politics,
deric,
social cognition,
technology
Friday, October 24, 2008
Distortion of science by headline-grabbing
I'm always being concerned in scanning journals for possible postings in this blog that my eye is too readily caught by the flashy marketing phrase or popularizing twist, thus neglecting more boring, but possibly much more significant, work. An article in The Economist reinforces my concern by pointing to work of Young Ioannidis, and Al-Ubaydli in PLos Medicine. that uses economic commodity theory to show how the current scientific publishing system is biased towards favoring trumpeted results that are also more likely to be false.
In economic theory the winner’s curse refers to the idea that someone who places the winning bid in an auction may have paid too much. Consider, for example, bids to develop an oil field. Most of the offers are likely to cluster around the true value of the resource, so the highest bidder probably paid too much.
The same thing may be happening in scientific publishing, according to a new analysis. With so many scientific papers chasing so few pages in the most prestigious journals, the winners could be the ones most likely to oversell themselves—to trumpet dramatic or important results that later turn out to be false. This would produce a distorted picture of scientific knowledge, with less dramatic (but more accurate) results either relegated to obscure journals or left unpublished.
It starts with the nuts and bolts of scientific publishing. Hundreds of thousands of scientific researchers are hired, promoted and funded according not only to how much work they produce, but also to where it gets published. For many, the ultimate accolade is to appear in a journal like Nature or Science. Such publications boast that they are very selective, turning down the vast majority of papers that are submitted to them.
The assumption is that, as a result, such journals publish only the best scientific work. But Dr Ioannidis and his colleagues argue that the reputations of the journals are pumped up by an artificial scarcity of the kind that keeps diamonds expensive. And such a scarcity, they suggest, can make it more likely that the leading journals will publish dramatic, but what may ultimately turn out to be incorrect, research.
How we know our own minds...
For those of you who might be more heavily into philosophy of mind and introspective psychology, I want to pass along this PDF of a draft article that is to appear in Brain and Behavioral Sciences, "How we know our own minds: the relationship between mindreading and metacognition." Carruthers defends the idea that our knowledge of our own attitudes results from turning our mindreading capacities upon ourselves, not from introspection for propositional attitudes. Here is his abstract, showing the organization of his arguments:
Four different accounts of the relationship between third-person mindreading and first-person metacognition are compared and evaluated. While three of them endorse the existence of introspection for propositional attitudes, the fourth (defended here) claims that our knowledge of our own attitudes results from turning our mindreading capacities upon ourselves. Section 1 introduces the four accounts. Section 2 develops the “mindreading is prior” model in more detail, showing how it predicts introspection for perceptual and quasi-perceptual (e.g. imagistic) mental events while claiming that metacognitive access to our own attitudes always results from swift unconscious self-interpretation. It also considers the model’s relationship to the expression of attitudes in speech. Section 3 argues that the commonsense belief in the existence of introspection should be given no weight. Section 4 argues briefly that data from childhood development are of no help in resolving this debate. Section 5 considers the evolutionary claims to which the different accounts are committed, and argues that the three introspective views make predictions that aren’t borne out by the data. Section 6 examines the extensive evidence that people often confabulate when self-attributing attitudes. Section 7 considers “two systems” accounts of human thinking and reasoning, arguing that although there are inrospectable events within System 2, there are no introspectable attitudes. Section 8 examines alleged evidence of “unsymbolized thinking”. Section 9 considers the claim that schizophrenia exhibits a dissociation between mindreading and metacognition. Finally, Section 10 evaluates the claim that autism presents a dissociation in the opposite direction, of metacognition without mindreading.
Thursday, October 23, 2008
Different aspects of human intelligence correlate with cortical thickness versus neural activation.
Choi et al. report an interesting study in the Journal of Neuroscience. I'm passing on the abstract and a bit of explanation of crystallized versus fluid intelligence, but not the usual flashy fMRI graphics:
We hypothesized that individual differences in intelligence (Spearman's g) are supported by multiple brain regions, and in particular that fluid (gF) and crystallized (gC) components of intelligence are related to brain function and structure with a distinct profile of association across brain regions. In 225 healthy young adults scanned with structural and functional magnetic resonance imaging sequences, regions of interest (ROIs) were defined on the basis of a correlation between g and either brain structure or brain function. In these ROIs, gC was more strongly related to structure (cortical thickness) than function, whereas gF was more strongly related to function (blood oxygenation level-dependent signal during reasoning) than structure. We further validated this finding by generating a neurometric prediction model of intelligence quotient (IQ) that explained 50% of variance in IQ in an independent sample. The data compel a nuanced view of the neurobiology of intelligence, providing the most persuasive evidence to date for theories emphasizing multiple distributed brain regions differing in function.As background:
gC, sometimes described as verbal ability, is more dependent on accumulated knowledge in long-term storage, including semantic memory. gF refers to reasoning ability, and is known to depend on working memory. Although gC and gF are typically correlated and can be considered subfactors of g (Jensen), they are conceptually and empirically separable. For instance, gC continues to increase over the lifespan, but gF peaks in early adulthood and then declines . Furthermore, at the neural level, lesion studies demonstrated that patients with anterior temporal damages perform poorly on tests of semantic knowledge, whereas prefrontal patients typically show profound deficits in solving diverse reasoning tasks.
Blog Categories:
brain plasticity,
genes,
human development
Sleep accelerates improvement in working memory.
I've mentioned the n-back task for improving working memory and intelligence in several - previous - posts. Kuriyama et al. now use this test to show that post-training sleep significantly enhances this improvement:
Working memory (WM) performance, which is an important factor for determining problem-solving and reasoning ability, has been firmly believed to be constant. However, recent findings have demonstrated that WM performance has the potential to be improved by repetitive training. Although various skills are reported to be improved by sleep, the beneficial effect of sleep on WM performance has not been clarified. Here, we show that improvement in WM performance is facilitated by posttraining naturalistic sleep. A spatial variant of the n-back WM task was performed by 29 healthy young adults who were assigned randomly to three different experimental groups that had different time schedules of repetitive n-back WM task sessions, with or without intervening sleep. Intergroup and intersession comparisons of WM performance (accuracy and response time) profiles showed that n-back accuracy after posttraining sleep was significantly improved compared with that after the same period of wakefulness, independent of sleep timing, subject's vigilance level, or circadian influences. On the other hand, response time was not influenced by sleep or repetitive training schedules. The present study indicates that improvement in n-back accuracy, which could reflect WM capacity, essentially benefits from posttraining sleep.
Wednesday, October 22, 2008
Cognitive therapy versus medication for depression
DeRubeis et al. offer an interesting review article in Nature Reviews Neuroscience on treatment outcomes and neural mechanisms, from which I pass on part of the abstract and some summary graphs:
Studies have shown that cognitive therapy is as efficacious as antidepressant medication at treating depression, and it seems to reduce the risk of relapse even after its discontinuation. Cognitive therapy and antidepressant medication probably engage some similar neural mechanisms, as well as mechanisms that are distinctive to each.
Cognitive therapy and antidepressant medication have comparable effects. This graph shows the response of outpatients who had moderate-to-severe depression to cognitive therapy (CT), antidepressant medication (ADM) or placebo. Patients who were assigned to ADM or to CT showed a significantly higher response rate after 8 weeks of treatment than those who were assigned to placebo. After 16 weeks of treatment the response rates of ADM and CT were almost identical.
Less relapse after cognitive therapy compared with antidepressant medication. The second phase of the parent antidepressant medication (ADM) versus cognitive therapy (CT) study followed patients who had responded to ADM or to CT3. Patients who had responded to ADM were randomly assigned to either continue ADM treatment for one year (beige and red lines) or to change to placebo treatment for 1 year (green line). Patients who responded to CT were allowed three sessions of CT during the 1-year continuation period. In the follow-up period, none of the patients received any treatment. The figure shows that prior treatment with CT protected against relapse of depression at least as well as the continued provision of ADM, and better than ADM treatment that was subsequently discontinued. Note that the patient group that was given ADM in the continuation year contained a number of patients who did not adhere to the medication regimen. The red line indicates the response of the ADM-continuation group including these non-compliant patients, whereas the beige line shows the response of the patients in this group after the non-compliant patients had been removed from the analysis.
After a graphic showing changes in blood-oxygen-level-dependent (BOLD) signal in response to cognitive and emotional tasks associated with cognitive therapy, the authors offer a summary hypothetical time course of the changes to amygdala and prefrontal function that are associated with antidepressant medication and cognitive therapy.
a | During acute depression, amygdala activity is increased (red) and prefrontal activity is decreased (blue) relative to activity in these regions in healthy individuals. b | Cognitive therapy (CT) effectively exercises the prefrontal cortex (PFC), yielding increased inhibitory function of this region. c | Antidepressant medication (ADM) targets amygdala function more directly, decreasing its activity. d | After ADM or CT, amygdala function is decreased and prefrontal function is increased. The double-headed arrow between the amygdala and the PFC represents the bidirectional homeostatic influences that are believed to operate in healthy individuals.
Our somatosensory cortex embodies the facial expressions of others
The Editor's choice section of science describes an interesting bit of work by Pitcher et al. showing the embodyment of our social cognition:
Humans are especially interested in faces, as a means of sending signals--witness the sizeable arc of somatosensory cortex devoted to representation of one's own face--and as a substrate for social cognition. Pitcher et al. describe results supporting theories of embodied cognition and emotion, which posit cognition and emotion as being shaped by our bodily movements and perceptions. They used repetitive transcranial magnetic stimulation (rTMS) to interfere with neural activity in the face areas of the somatosensory cortex while people discriminated the emotional expressions of faces (happy, sad, surprised, fearful, angry, and disgusted) and found that accuracy dropped significantly, as it also did when the occipital face area was similarly stimulated. The temporal sequence of neural processing was then delineated using double-pulse TMS, showing that the occipital area acted in the time window from 60 to 100 ms after the face stimulus was shown, whereas the somatosensory area was active a bit later, between 100 and 170 ms.
Blog Categories:
embodied cognition,
social cognition
Tuesday, October 21, 2008
Botnets
Here is a scary article.
Evolution of Religious Prosociality
Norenzayan and Shariff offer an interesting review article on empirical evidence for religious prosociality. Here is one clip and two figures from the article.
Agreement is emerging that selective pressures over the course of human evolution can explain the wide cross-cultural re-occurrence, historical persistence, and predictable cognitive structure of religious beliefs and behaviors. The tendency to detect agency in nature likely supplied the cognitive template that supports the pervasive belief in supernatural agents. These agents are widely believed to transcend physical, biological, and psychological limitations. However, other important details are subject to cultural variation. Although in many societies supernatural agents are not directly concerned with human morality, in many others, morally concerned agents use their supernatural powers to observe and, in some cases, to punish and reward human social interactions. Examples include the God of Abrahamic religions and Viracocha, the Incan supreme God, but also many morally concerned deities found in traditional societies, such as the adalo, ancestral spirits of the Kwaio Solomon islanders. These beliefs are likely to spread culturally to the extent that they facilitate ingroup cooperation. This could occur by conforming to individual psychology that favors reputation-sensitive prosocial tendencies, as the by-product account holds; by competition among social groups, as the cultural group selection account would suggest; or possibly by some combination of the two. Religious behaviors and rituals, if more costly to cooperating group members than to freeloaders, may have reliably signaled the presence of devotion and, therefore, cooperative intention toward ingroup members, in turn, buffering religious groups against defection from freeloaders and reinforcing cooperative norms. Religious prosociality, thus, may have softened the limitations that kinship-based and (direct or indirect) reciprocity-based altruism place on group size. In this way, the cultural spread of religious prosociality may have facilitated the rise of stable, large, cooperative communities of genetically unrelated individuals.
Figure - Implicit activation of God concepts, relative to a neutral prime, increased offers in the one-shot, anonymous Dictator Game. Priming secular concepts indicating moral authority had a similar effect. The results showed not only a quantitative increase in generosity, but also a qualitative shift in social norms. In the control group, the modal response was selfishness, a plurality of players pocketed all $10. In the God group, the mode shifted to fairness, a plurality of players split the money evenly (N = 75). It remains to be seen, however, whether these effects
would occur if the recipient was clearly marked as an outgroup member.
Figure - Life expectancy of religious versus secular communes. An analysis of 200 religious and secular communes in 19th-century America (29), for every year of their life course, religious communes were about four times as likely to survive than their secular counterparts. This difference remained after statistically controlling for type of commune movement, year founded, and year at risk of dissolution (the last control assesses major historical trends that may independently impact commune dissolution).
Redefining Depression as Mere Sadness
An article by Pies with the title of this post is worth reading. It deals with the criticism that modern psychiatric practice, in collusion with pill pushing pharmaceutical companies, has medicalized “normal sadness” brought on by external circumstances. (Added note: Pies has emailed this this link to a more detailed discussion posted on the PsychCentral website.) Here are some clips from the NYTimes article:
In their recent book “The Loss of Sadness” (Oxford, 2007), Allan V. Horwitz and Jerome C. Wakefield assert that for thousands of years, symptoms of sadness that were “with cause” were separated from those that were “without cause.” Only the latter were viewed as mental disorders.
With the advent of modern diagnostic criteria, these authors argue, doctors were directed to ignore the context of the patient’s complaints and focus only on symptoms — poor appetite, insomnia, low energy, hopelessness and so on. The current criteria for major depression, they say, largely fail to distinguish between “abnormal” reactions caused by “internal dysfunction” and “normal sadness” brought on by external circumstances. And they blame vested interests — doctors, researchers, pharmaceutical companies — for fostering this bloated concept of depression.
But while this increasingly popular thesis contains a kernel of truth, it conceals a bushel basket of conceptual and scientific problems.
For one thing, if modern diagnostic criteria were converting mere sadness into clinical depression, we would expect the number of new cases of depression to be skyrocketing compared with rates in a period like the 1950s to the 1970s. But several new studies in the United States and Canada find that the incidence of serious depression has held relatively steady in recent decades.
Second, it may seem easy to determine that someone with depressive complaints is reacting to a loss that touched off the depression. Experienced clinicians know this is rarely the case.
Third, and perhaps most troubling, is the implication that a recent major loss makes it more likely that the person’s depressive symptoms will follow a benign and limited course, and therefore do not need medical treatment. This has never been demonstrated, to my knowledge, in any well-designed studies. And what has been demonstrated, in a study by Dr. Sidney Zisook, is that antidepressants may help patients with major depressive symptoms occurring just after the death of a loved one.
Monday, October 20, 2008
The iPathology of your iBrain
Small and Vorgan offer an engaging article in Scientific American Mind on how daily exposure to television, computers, smart phones, video games, search engines and web browsers is rewiring our brains. A modern generation is rising with brains that are very different from the brains of those of us whose basic brain wiring was laid down in a time when direct social interactions were more the norm. One of the authors (Small) compared brain activities in computer- savvy versus computer-naive 50-60 year olds while searching for accurate information on a topic using Google, subtracting activity associated with just reading a text to determine activity specific to the searching function (which was the same in the two groups). In the baseline scanning session during searching on Google, the computer-savvy subjects engaged their dorsolateral prefrontal cortex while the Internet-naive subjects showed minimal activation in this region. After just five days of practice,the exact same neural circuitry in the front part of the brain became active in the Internet-naive subjects. Five hours on the Internet, and these participants had already rewired their brains.
Our high-tech revolution has plunged us into a state of “continuous partial attention,” which software executive Linda Stone, who coined the term in 1998, describes as continually staying busy—keeping tabs on everything while never truly focusing on anything. Continuous partial attention differs from multitasking, wherein we have a purpose for each task and we are trying to improve efficiency and productivity. Instead, when our minds partially attend, and do so continuously, we scan for an opportunity for any type of contact at every given moment. We virtually chat as our text messages flow, and we keep tabs on active buddy lists (friends and other screen names in an instant message program); everything, everywhere, is connected through our peripheral attention. Although having all our pals online from moment to moment seems intimate, we risk losing personal touch with our real-life relationships and may experience an artificial sense of intimacy as compared with when we shut down our devices and devote our attention to one
individual at a time.
When paying continuous partial attention, people may place their brain in a heightened state of stress. They no longer have time to reflect, contemplate or make thoughtful decisions. Instead they exist in a sense of constant crisis—on alert for a new contact or bit of exciting news or information at any moment. Once people get used to this state, they tend to thrive on the perpetual connectivity. It feeds their ego and sense of self-worth, and it becomes irresistible. Neuroimaging studies suggest that this sense of selfworth may protect the size of the hippocampus—the horseshoeshaped brain region in the medial (inward-facing) temporal lobe, which allows us to learn and remember new information. Psychiatry professor Sonia J. Lupien and her associates at McGill University studied hippocampal size in healthy younger and older adult volunteers. Measures of self esteem correlated significantly with hippocampal size, regardless of age. They also found that the more people felt in control of their lives, the larger the hippocampus. But at some point, the sense of control and self-worth we feel when we maintain continuous partial attention tends to break down—our brains were not built to sustain such monitoring for extended periods. Eventually the hours of unrelenting digital connectivity can create a unique type of brain strain. Many people who have been working on the Internet for several hours without a break report making frequent errors in their work. On signing off, they notice feeling spaced out, fatigued, irritable and distracted, as if they are in a “digital fog.” This new form of mental stress, what Small terms “techno-brain burnout,” is threatening to become an epidemic. Under this kind of stress, our brains instinctively signal the adrenal gland to secrete cortisol and adrenaline. In the short run, these stress hormones boost energy levels and augment memory, but over time they actually impair cognition, lead to depression, and alter the neural circuitry in the hippocampus, amygdala and prefrontal cortex—the brain regions that control mood and thought. Chronic and prolonged techno-brain burnout can even reshape the underlying brain structure.
While the brains of today’s digital natives are wiring up for rapid-fire cyber searches, however, the neural circuits that control the more traditional learning methods are neglected and gradually diminished. The pathways for human interaction and communication weaken as customary one-on-one people skills atrophy. Our U.C.L.A. research team and other scientists have shown that we can intentionally alter brain wiring and reinvigorate some of these dwindling neural pathways, even while the newly evolved technology circuits bring our brains to extraordinary levels of potential.
Blog Categories:
brain plasticity,
culture/politics,
human development,
technology
Bayesian estimation on the presidential election.
From the "Random Samples" section of the Oct. 17 Science Magazine:
In the winner-take-all world of politics, candidates know that even a modest lead in the polls can spell almost certain victory. Sheldon Jacobson, an operations research specialist at the University of Illinois, Urbana-Champaign, and colleagues, including a group of students, have attempted to quantify that insight for the current United States presidential election, putting their predictions for the Electoral College on a Web site, election08.cs.uiuc.edu. Using a statistical method known as Bayesian estimation, they combined an analysis of results from the 2004 Bush-versus-Kerry contest with current state-by-state polls for Obama versus McCain to produce probabilities for each candidate of carrying each state. They then converted the estimates into a probability distribution for the total number of Electoral College votes a candidate might receive. In Indiana, for example, polls as of 4 October gave McCain a slight 2.5% lead. But given that Bush carried Indiana in 2004 by 20.7%, a Bayesian calculation indicates McCain's chance of winning the state's 11 Electoral College votes at about 87%. Most states are now in the bag for one candidate or the other; only a handful are truly in Bayesian play. Current calculations give McCain no chance of victory. "However," Jacobson cautions, "if the polls move, then so will our forecasts."
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