Sensory experience during development can modify the CNS and alter adult perceptual skills. While this principle draws support from deprivation or chronic stimulus exposure studies, the effect of training is addressed only in adults. Here, we asked whether a brief period of training during development can exert a unique impact on adult perceptual skills. Juvenile gerbils were trained to detect amplitude modulation (AM), a stimulus feature elemental to animal communication sounds. When the performance of these juvenile-trained animals was subsequently assessed in adulthood, it was superior to a control group that received an identical regimen of training as adults. The juvenile-trained animals displayed significantly better AM detection thresholds. This was not observed in an adult group that received only exposure to AM stimuli as juveniles. To determine whether enhanced adult performance was due solely to learning the conditioned avoidance procedure, juveniles were trained on frequency modulation (FM) detection, and subsequently assessed on AM detection as adults. These animals displayed significantly poorer AM detection thresholds than all other groups. Thus, training on a specific auditory task (AM detection) during development provided a benefit to performance on that task in adulthood, whereas an identical training regimen in adulthood did not bring about this enhancement. In contrast, there was a cost, in adulthood, following developmental training on a different task (FM detection). Together, the results demonstrate a period of heightened sensitivity in the developing CNS such that behavioral training in juveniles has a unique impact on adult behavioral capabilities.
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, April 21, 2011
Juvenile training improves adult skills - at a cost.
Sarro and Sanes ask whether there are long-term effects of early sensory training that can only be assessed after maturation. The experiments examine auditory processing in gerbils and find that early training in detecting amplitude modulation yield adults with abilities superior to other animals trained as adults. This would probably hold for us humans, but you don't do conditioned avoidance experiments on human infants...
Wednesday, April 20, 2011
Pain reduction by mindfulness meditation - brain correlates
Zeidan et al. offer these interesting results on possible consequences of a form of mindfulness meditation called Shamatha, or focused attention, which is a cognitive practice of sustaining attention on the changing sensations of the breath, monitoring discursive events as they arise, disengaging from those events without affective reaction, and redirecting attention back to the breath. Slightly edited clips from the abstract:
The subjective experience of one's environment is constructed by interactions among sensory, cognitive, and affective processes. For centuries, meditation has been thought to influence such processes by enabling a nonevaluative representation of sensory events. To better understand how meditation influences the sensory experience, we used arterial spin labeling functional magnetic resonance imaging to assess the neural mechanisms by which mindfulness meditation influences pain in healthy human participants. After 4 d of mindfulness meditation training, meditating in the presence of noxious stimulation significantly reduced pain unpleasantness by 57% and pain intensity ratings by 40% when compared to rest... Meditation reduced pain-related activation of the contralateral primary somatosensory cortex [note: the noxious stimulus was a thermal stimulator placed on the rear right calf, and thus would be reported to the left (contralateral) somatosensory cortex]...Meditation-induced reductions in pain intensity ratings were associated with increased activity in the anterior cingulate cortex and anterior insula, areas involved in the cognitive regulation of nociceptive (pain) processing. Reductions in pain unpleasantness ratings were associated with orbitofrontal cortex activation, an area implicated in reframing the contextual evaluation of sensory events. Moreover, reductions in pain unpleasantness also were associated with thalamic deactivation, which may reflect a limbic gating mechanism involved in modifying interactions between afferent input and executive-order brain areas. Together, these data indicate that meditation engages multiple brain mechanisms that alter the construction of the subjectively available pain experience from afferent (incoming) information.
Blog Categories:
attention/perception,
fear/anxiety/stress,
meditation
Tuesday, April 19, 2011
Self control makes us angry
In several different places I have come across this interesting article by Gal and Liu. Exerting self control is usually assoicated with positive emotions and wellbeing, but some research has also shown that exerting self control can lead to increased aggression. The authors:
Goal Frustration - primitive and evolutionary roots drive angry facial expressions and the autonomic response of facial flushing in a newborn baby when a sucking treat is removed.
Diminished sense of Autonomy - anger from the sense that one‟s sense of freedom is restricted and that one is "forced" to choose the virtuous path rather than indulgence.
Ego depletion - the state of being depleted (not having the short term goal deferred for the long term goal) makes people angry.
...find that exerting self control is associated with angry behavior more broadly. In particular, using a “matched-choice paradigm,” we find that after exerting self control people exhibit increased preference for anger-themed content, greater interest in faces exhibiting anger, greater endorsement of anger-framed appeals, and greater irritation to others‟ attempts to control one‟s behavior.The authors note that because the anger-related behaviors examined in their experiments are not inappropriate, they are unlikely to reflect diminished capacities of self-regulation. Three of the several possible reasons why exerting self-control might elicit (implicit) anger they list are:
Goal Frustration - primitive and evolutionary roots drive angry facial expressions and the autonomic response of facial flushing in a newborn baby when a sucking treat is removed.
Diminished sense of Autonomy - anger from the sense that one‟s sense of freedom is restricted and that one is "forced" to choose the virtuous path rather than indulgence.
Ego depletion - the state of being depleted (not having the short term goal deferred for the long term goal) makes people angry.
Monday, April 18, 2011
Dialing numbers on your cellphone can elicit concepts
Observations by Topolinski note an interesting consequence of our cell phone habits:
When people perform actions, effects associated with the actions are activated mentally, even if those effects are not apparent. This study tested whether sequences of simulations of virtual action effects can be integrated into a meaning of their own. Cell phones were used to test this hypothesis because pressing a key on a phone is habitually associated with both digits (dialing numbers) and letters (typing text messages). In the first experiment, dialing digit sequences induced the meaning of words that share the same key sequence (e.g., 5683, LOVE). This occurred even though the letters were not labeled on the keypad, and participants were not aware of the digit-letter correspondences. In a second experiment, subjects preferred dialing numbers implying positive words (e.g., 37326, DREAM) over dialing numbers implying negative words (e.g., 75463, SLIME). Finally, subjects preferred companies with phone numbers implying a company-related word (e.g., LOVE for a dating agency, CORPSE for a mortician) compared with companies with phone numbers implying a company-unrelated word.
Friday, April 15, 2011
Outsourcing self regulation
It seems reasonable that thinking about supportive partners should be motivationally bolstering - leading us to work harder. Fitzsimonds and Finkel make observations that suggest just the opposite - that such thoughts are motivationally undermining, causing us to make less ambitious plans to pursue goals and to spend less time on the pursuit.
The their first experiment,
The their first experiment,
...participants who thought about how their partner helped them with health goals (as opposed to career goals) planned to spend less time and effort on health goals in the upcoming week. This pattern was stronger for depleted participants than for nondepleted participants.In a second experiment,
...participants who thought about how their partner helped them with academic-achievement goals procrastinated more, leaving themselves less time for an academic task, than did participants in two control conditions. This pattern was stronger for participants who were told that procrastinating would drain their resources for the academic task than for participants who were told that procrastinating would not drain their resources for that task.A final experiment
...found that participants who decreased their effort after thinking of an instrumental significant other reported higher relationship commitment to that individual than did participants who did not decrease their effort.The authors suggest that:
...partners may develop shared self-regulatory systems, or “transactive self-control,” relying on each other for help with self-control. Individuals who rely on their romantic partner for help with self-control in one area may be able to conserve valuable resources for other goal pursuits. If so, such a shared self-regulatory system—although it could ironically undermine short-term outcomes, as in the case of the outsourcing phenomenon shown here—could ultimately benefit partners if it allowed them to best make use of their limited self-control resources over time.
Thursday, April 14, 2011
A long, diligent life...
Lagergren reviews Friedman and Martin's recent book on the 8-decade long longevity study started in 1921 at Stanford University by Lewis Terman, which has followed the histories of 1,500 gifted children from schools in the state and followed them from the age of 11 into adulthood, collecting a variety of data to see what might predict later success and accomplishment. The recent update collects information on those who have died.
Some results are as expected, such as that smoking is bad for longevity. Others turn conventional wisdom on its head...working hard for long hours in a demanding job to achieve high status is better for your health and life expectancy than taking it easy and lacking ambition. Marriage is a blessing for men more than women; and men suffer more adverse health effects from divorce, perhaps turning to drink or drugs. The authors emphasize the benefits of an active social network — more common for women — as a buffer against life's harmful events. And they are critical of simple health advice, such as to jog or eat less fat, arguing that it is the whole approach to life that is essential, not the details. To give a person a list of health recommendations does not work, they point out, if the person cannot or does not follow them.
The best predictor of a long and healthy life turned out to be conscientiousness — the extent to which a child was prudent, dependable and persistent in the accomplishment of his or her goals...You do not become conscientious overnight. It is the long-term, determined work of adopting and sticking to healthy habits and seeking good social environments and relationships that makes the difference. Later follow-up of Terman's subjects showed that conscientiousness in middle age and later counts almost as much as in childhood... Conscientious people do more to protect their health and are less likely to engage in risky activities such as smoking, drinking or drug-taking, the study found. They also find their way to happier marriages, better friendships and optimum work situations. As a result, they are less likely to die from all causes...
Being physically active as a child is also a predictor of longevity, but only if that activity is maintained into and beyond middle age. The life-years gained by jogging may amount to no more than the time you spend doing it, the authors note. So we needn't all aim to run marathons; rather, we should just maintain an activity that we enjoy.
Wednesday, April 13, 2011
Disorder promotes discrimination and stereotyping
Stapel and Lindenberg find that environmental signs of disorder, such as uncollected trash at a train station or cars parked askew on a sidewalk, are sufficient to induce bystanders to desire orderliness. The consequences are that these bystanders elect to sit further from minorities when asked to fill in a survey and donated less of their payments (for participating in the survey) to help immigrants and the homeless. The desire for order is fulfilled by an increased propensity toward classification, which includes stereotyping. [One field study used the Utrecht train hub in the middle of the Netherlands, where thousands of travelers pass through on a daily basis. During a cleaners’ strike, the train station quickly turned into a dirty and disordered environment. After the station had not been cleaned for a few days in a row, the authors asked 40 travelers who were waiting for their train to participate in their study in return for a candy bar or an apple. They were asked to judge the extent to which they thought certain traits applied to a particular group (in their case, Muslims, homosexuals, and the Dutch). The laboratory experiments, where behaviors after pictures of order versus disorder were used, employed 40-70 subjects.]. Here is their abstract:
Being the victim of discrimination can have serious negative health- and quality-of-life–related consequences. Yet, could being discriminated against depend on such seemingly trivial matters as garbage on the streets? In this study, we show, in two field experiments, that disordered contexts (such as litter or a broken-up sidewalk and an abandoned bicycle) indeed promote stereotyping and discrimination in real-world situations and, in three lab experiments, that it is a heightened need for structure that mediates these effects (number of subjects: between 40 and 70 per experiment). These findings considerably advance our knowledge of the impact of the physical environment on stereotyping and discrimination and have clear policy implications: Diagnose environmental disorder early and intervene immediately.
Tuesday, April 12, 2011
Hurt the flesh, cleanse the soul....
Here are some summary, slightly edited, clips from an interesting study by Bastian et al. (performed on the usual batch of college undergraduates, paid $10 for their participation in the study):
Pain purifies. History is replete with examples of ritualized or self-inflicted pain aimed at achieving purification...When reminded of an immoral deed, people are motivated to experience physical pain. Student participants in the study who wrote about an unethical behavior not only held their hands in ice water longer but also rated the experience as more painful than did participants who wrote about an everyday interaction. Critically, experiencing pain reduced people’s feelings of guilt, and the effect of the painful task on ratings of guilt was greater than the effect of a similar but nonpainful task.
Pain has traditionally been understood as purely physical in nature, but it is more accurate to describe it as the intersection of body, mind, and culture. People give meaning to pain, and we argue that people interpret pain within a judicial model of pain as punishment. Our results suggest that the experience of pain has psychological currency in rebalancing the scales of justice—an interpretation of pain that is analogous to notions of retributive justice. Interpreted in this way, pain has the capacity to resolve guilt.
People are socialized to understand pain within this judicial framework. Physical pain is employed as a penalty (e.g., spanking children for misbehavior), and unexplained pain is often understood as punishment from God. The judicial model is explicit in the Latin word for pain, poena, which means “to pay the penalty.” Understood this way, pain may be perceived as repayment for sin in three ways. First, pain is the embodiment of atonement. Just as physical cleansing washes away sin, physical pain is experienced as a penalty, and paying that penalty reestablishes moral purity. Second, subjecting oneself to pain communicates remorse to others (including God) and signals that one has paid for one’s sins, and this removes the threat of external punishment. Third, tolerating the punishment of pain is a test of one’s virtue, reaffirming one’s positive identity to oneself and others.
Previous work has demonstrated that giving meaning to pain affects people’s management of that pain. By introducing the judicial model of pain, we emphasize that giving meaning to pain can also affect other psychological processes. Although additional research is needed, our findings demonstrate that experiencing pain as a penalty can cause people to feel that their guilt is resolved and their soul cleansed.
Monday, April 11, 2011
Improving your cognitive toolkit - VII
Continuation of my sampling of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":
Alun Anderson - Homo Dilatus
Alun Anderson - Homo Dilatus
Our species might well be renamed Homo Dilatus, the procrastinating ape. Somewhere in our evolution we acquired the brain circuitry to deal with sudden crises and respond with urgent action. Steady declines and slowly developing threats are quite different. "Why act now when the future is far off," is the maxim for a species designed to deal with near-term problems and not long term uncertainties. It's a handy view of humankind which everyone who uses science to change policy should keep in their mental took kit, and one that that is greatly reinforced by the endless procrastination in tacking climate change. Cancun follows Copenhagen follows Kyoto but the more we dither and no extraordinary disaster follows, the more dithering seems just fine.Geoffrey Miller - Personality traits are continuous with mental illnesses
Such behaviour is not unique to climate change. It took the sinking of the Titanic to put sufficient life boats on passenger ships, the huge spill from the Amoco Cadiz to set international marine pollution rules and the Exxon Valdez disaster to drive the switch to double-hulled tankers. The same pattern is seen in the oil industry, with the Gulf spill the latest chapter in the disaster first-regulations later mindset of Homo dilatus.
Our instinctive way of thinking about insanity — our intuitive psychiatry — is dead wrong... There's a scientific consensus that personality traits can be well-described by five main dimensions of variation. These "Big Five" personality traits are called openness, conscientiousness, extraversion, agreeableness, and emotional stability. The Big Five are all normally distributed in a bell curve, statistically independent of each other, genetically heritable, stable across the life-course, unconsciously judged when choosing mates or friends, and found in other species such as chimpanzees. They predict a wide range of behavior in school, work, marriage, parenting, crime, economics, and politics.
Mental disorders are often associated with maladaptive extremes of the Big Five traits. Over-conscientiousness predicts obsessive-compulsive disorder, whereas low conscientiousness predicts drug addiction and other "impulse control disorders". Low emotional stability predicts depression, anxiety, bipolar, borderline, and histrionic disorders. Low extraversion predicts avoidant and schizoid personality disorders. Low agreeableness predicts psychopathy and paranoid personality disorder. High openness is on a continuum with schizotypy and schizophrenia. Twin studies show that these links between personality traits and mental illnesses exist not just at the behavioral level, but at the genetic level. And parents who are somewhat extreme on a personality trait are much more likely to have a child with the associated mental illness.
Friday, April 08, 2011
Music and language - differing brain activations
Rogalsky et al. obtain data that fills out in much more detail a description of which brain activations overlap and which differ during the processing of speech versus music. Here is their abstract, following by a figure from the paper:
Language and music exhibit similar acoustic and structural properties, and both appear to be uniquely human. Several recent studies suggest that speech and music perception recruit shared computational systems, and a common substrate in Broca's area for hierarchical processing has recently been proposed. However, this claim has not been tested by directly comparing the spatial distribution of activations to speech and music processing within subjects. In the present study, participants listened to sentences, scrambled sentences, and novel melodies. As expected, large swaths of activation for both sentences and melodies were found bilaterally in the superior temporal lobe, overlapping in portions of auditory cortex. However, substantial nonoverlap was also found: sentences elicited more ventrolateral activation, whereas the melodies elicited a more dorsomedial pattern, extending into the parietal lobe. Multivariate pattern classification analyses indicate that even within the regions of blood oxygenation level-dependent response overlap, speech and music elicit distinguishable patterns of activation. Regions involved in processing hierarchical aspects of sentence perception were identified by contrasting sentences with scrambled sentences, revealing a bilateral temporal lobe network. Music perception showed no overlap whatsoever with this network. Broca's area was not robustly activated by any stimulus type. Overall, these findings suggest that basic hierarchical processing for music and speech recruits distinct cortical networks, neither of which involves Broca's area. We suggest that previous claims are based on data from tasks that tap higher-order cognitive processes, such as working memory and/or cognitive control, which can operate in both speech and music domains.
Figure - regions selective for speech versus music. Speech stimuli selectively activates more lateral regions in the superior temporal lobe bilaterally, while music stimuli selectively activate more medial anterior regions on the supratemporal plane and extending into the insula, primarily in the right hemisphere. (This apparently lateralized pattern for music does not mean that the right hemisphere preferentially processes music stimuli as is often assumed. An analysis in the paper also shows that music activates both hemispheres rather symmetrically; the lateralization effect is in the relative activation patterns to music versus speech.)
Thursday, April 07, 2011
Elephants know when they need a helping trunk.
From de Waal and collaborators, evidence for convergent evolution of cooperation:
Elephants are widely assumed to be among the most cognitively advanced animals, even though systematic evidence is lacking. This void in knowledge is mainly due to the danger and difficulty of submitting the largest land animal to behavioral experiments. In an attempt to change this situation, a classical 1930s cooperation paradigm commonly tested on monkeys and apes was modified by using a procedure originally designed for chimpanzees (Pan troglodytes) to measure the reactions of Asian elephants (Elephas maximus). This paradigm explores the cognition underlying coordination toward a shared goal. What do animals know or learn about the benefits of cooperation? Can they learn critical elements of a partner's role in cooperation? Whereas observations in nature suggest such understanding in nonhuman primates, experimental results have been mixed, and little evidence exists with regards to nonprimates. Here, we show that elephants can learn to coordinate with a partner in a task requiring two individuals to simultaneously pull two ends of the same rope to obtain a reward. Not only did the elephants act together, they inhibited the pulling response for up to 45 s if the arrival of a partner was delayed. They also grasped that there was no point to pulling if the partner lacked access to the rope. Such results have been interpreted as demonstrating an understanding of cooperation. Through convergent evolution, elephants may have reached a cooperative skill level on a par with that of chimpanzees.
Wednesday, April 06, 2011
The brains of experts - due to predispositions and/or training?
Here is how Golestant et al. frame their interesting study on the brains of expert Phoneticians - who typically spend one to four years of formal training learning to identify speech sounds and to transcribe them into an international phonetic alphabet. (Remember, you can view any of the brain structures they mention by simply entering their name in Google Image Search.) The work suggests that morphological brain differences at birth might well influence career choices. We tend to enjoy and get reinforcement for doing things we are good at. (I've always wondered about a brain correlate for my ability, from a young age, to sight read any piece of sheet music put in front of me.)
Expertise has been shown to have both functional and structural correlates in the human brain. For example, expert golfers show a different pattern of neural activity than novice golfers when planning shots, and London taxi drivers have a larger posterior hippocampal volume than matched controls. It can be difficult to establish, however, the extent to which these effects relate to preexisting differences between the novice and expert groups, or whether these effects mainly arise from training-induced plasticity. Here we investigate brain anatomy in expert phoneticians...to distinguish experience-dependent plasticity from brain structural features that existed before the onset of expertise training.From their abstract:
...We found a positive correlation between the size of left pars opercularis and years of phonetic transcription training experience, illustrating how learning may affect brain structure. Phoneticians were also more likely to have multiple or split left transverse gyri in the auditory cortex than nonexpert controls, and the amount of phonetic transcription training did not predict auditory cortex morphology. The transverse gyri are thought to be established in utero; our results thus suggest that this gross morphological difference may have existed before the onset of phonetic training, and that its presence confers an advantage of sufficient magnitude to affect career choices. These results suggest complementary influences of domain-specific predispositions and experience-dependent brain malleability, influences that likely interact in determining not only how experience shapes the human brain but also why some individuals become engaged by certain fields of expertise.
Blog Categories:
attention/perception,
deric,
language,
music
Tuesday, April 05, 2011
Competitions for memory, it's stabilization, and a memory enhancer
Kuhl et al. find that the competition in the brain between old memories and new ones that are associated with the same thing (for example, an old versus a new password, or yesterday's versus today's space in the parking lot) can be observed in fMRI. They found competition between visual memories was captured in the relative degree to which target vs. competing memories were reactivated within the ventral occipitotemporal cortex. When lowered VOTC reactivation indicated that conflict between target and competing memories was high, frontoparietal mechanisms were markedly engaged, revealing specific neural mechanisms that tracked competing mnemonic evidence.
In another study on memory Diekelmann et al. show that memory reactivation has opposing effects on memory stability during wakefulness and sleep. Reactivation during slow-wave sleep following learning can stabilize memories. Reactivation during wakefulness has the opposite effect, rendering memories labile and susceptible to modest modification.
Finally Benedict Carey points to a study by Shema et al. showing that increasing levels of a brain enzyme (a protein kinase C isoform) involved in memory formation enhances long term memory. Also, Chen et al. show that injections of a different protein, a growth factor involved in memory formation (insulin-like growth factor II) can have the same effect.
In another study on memory Diekelmann et al. show that memory reactivation has opposing effects on memory stability during wakefulness and sleep. Reactivation during slow-wave sleep following learning can stabilize memories. Reactivation during wakefulness has the opposite effect, rendering memories labile and susceptible to modest modification.
Finally Benedict Carey points to a study by Shema et al. showing that increasing levels of a brain enzyme (a protein kinase C isoform) involved in memory formation enhances long term memory. Also, Chen et al. show that injections of a different protein, a growth factor involved in memory formation (insulin-like growth factor II) can have the same effect.
Monday, April 04, 2011
Increasing the viewed size of a painful body part reduces the pain
Here's an interesting and useful bit from Mancini et al.:
Pain is a complex subjective experience that is shaped by numerous contextual factors. For example, simply viewing the body reduces the reported intensity of acute physical pain. In this study, we investigated whether this visually induced analgesia is modulated by the visual size of the stimulated body part. We measured contact heat-pain thresholds while participants viewed either their own hand or a neutral object in three size conditions: reduced, actual size, or enlarged. Vision of the body was analgesic, increasing heat-pain thresholds by an average of 3.2 °C. We further found that visual enlargement of the viewed hand enhanced analgesia, whereas visual reduction of the hand decreased analgesia. These results demonstrate that pain perception depends on multisensory representations of the body and that visual distortions of body size modulate sensory components of pain.
Blog Categories:
attention/perception,
emotion,
fear/anxiety/stress
Saturday, April 02, 2011
Dynamic Views of Mindblog
I just pulled up the Blogger edit postings page for this blog and up pops a message "Did you know that...."
Turns out they have now added "Dynamic Views" - different ways of viewing a blog (flipcard, mosaic, sidebar, and timeslide...snapshot does not work for MindBlog) Click on the Dynamic Views of MindBlog link at the upper right to view several different viewing options.
Turns out they have now added "Dynamic Views" - different ways of viewing a blog (flipcard, mosaic, sidebar, and timeslide...snapshot does not work for MindBlog) Click on the Dynamic Views of MindBlog link at the upper right to view several different viewing options.
Friday, April 01, 2011
A bad taste in the mouth - more on embodied cognition and emotion
Eskine et al. provide yet another example of how emotion induced by a physical stimulus can influence a moral stance. (Previous mindblog postings have noted this effect for hard/soft or rough/smooth surfaces, hot/cold temperature stimuli, clean/dirty smells or visual images, etc.) The experimental subjects were the usual captive college psychology course undergraduates (54 of them in this case):
Can sweet-tasting substances trigger kind, favorable judgments about other people? What about substances that are disgusting and bitter? Various studies have linked physical disgust to moral disgust, but despite the rich and sometimes striking findings these studies have yielded, no research has explored morality in conjunction with taste, which can vary greatly and may differentially affect cognition. The research reported here tested the effects of taste perception on moral judgments. After consuming a sweet beverage, a bitter beverage, or water, participants rated a variety of moral transgressions. Results showed that taste perception significantly affected moral judgments, such that physical disgust (induced via a bitter taste) elicited feelings of moral disgust. Further, this effect was more pronounced in participants with politically conservative views than in participants with politically liberal views. Taken together, these differential findings suggest that embodied gustatory experiences may affect moral processing more than previously thought.
Thursday, March 31, 2011
MindBlog is on the road.
This is just a note that my seasonal migration from Fort Lauderdale, FL., back to the Univ. of Wisconsin in Madison, WI., starts today as I pack my two Abyssinian cats in the car and drive first to Austin, TX. to visit my son and his wife who live in the family house I grew up in. This Sunday I will be giving a recital of Fantasies for the piano, using the Steinway B at a hall at Westminster Manor, where my parents spent their final years. Then a week or so later, cats and I continue the trip to Madison. (Any blog readers who are in the Austin area and might wish to hear the music are welcome to email me. Program: Haydn - Fantasia in C major; Mozart - Fantasia in C Minor; Chopin - Fantasy in F minor; Liszt - Années de pèlerinage - Vallee d'Obermann; Debussy - Estampes III. Jardins sous la pluie).
Blocking arthritis pain in the brain.
Understanding how inflammation works is becoming increasingly urgent to aging persons (like myself) who view with alarm the increasing reactivity of their innate immune system that can cause arthritic flare-ups, or autoimmune and autoinflammatory diseases such as chronic rheumatoid arthritis. Diamond and Tracey do a brief review of interesting work by Hess et al. showing that that patients with rheumatoid arthritis who receive inhibitors of TNF, a major inflammatory cytokine, develop significant changes in brain activity before resolution of inflammation in the affected joints. From their review:
During the first century, the Roman physician Cornelius Celsus defined four cardinal signs of inflammation: redness, swelling, heat, and pain. These signs and symptoms occur during infection by invasive pathogens or as a consequence of trauma. Today, we understand the molecular basis of these physiological responses as mediated by cytokines and other factors produced by cells of the innate immune system. Cytokines are both necessary and sufficient to cause pathophysiological alterations manifested as the four cardinal signs. Importantly, this knowledge has enabled the development of highly selective therapeutical agents that target individual cytokines to prevent or reverse inflammation. For example, selective inhibitors of TNF, a major inflammatory cytokine, have revolutionized the therapy of rheumatoid arthritis, inflammatory bowel disease, and other autoimmune and autoinflammatory diseases affecting millions worldwide. Now, in PNAS, Hess et al. use functional MRI to monitor brain activity and report that patients with rheumatoid arthritis who receive anti-TNF develop significant changes in brain activity before resolution of inflammation in the affected joints.
To accomplish this, the authors measured blood oxygen level-dependent (BOLD) signals in the brain after compressing the metacarpal phalangeal joints of the arthritic hand. They observe enhanced activity in the brain regions associated with pain perception, including the thalamus, somatosensory cortex, and limbic system, regions known to process body sensations and emotions associated with the pain experience ( 1). Brain activity was significantly reduced within 24 h after treatment with TNF inhibitors, a time frame that preceded any observable evidence of reduced signs of inflammation in affected joints. Clinical composite scores, comprising measurements of C-reactive protein, a circulating marker of inflammation severity, were not improved until after 24 h. This suggests that selective inhibition of TNF has a primary early effect on the nervous system pain centers.
Blog Categories:
attention/perception,
emotion,
fear/anxiety/stress
Wednesday, March 30, 2011
Sleep deprivation biases economic risk-taking.
Venkatraman et al. make these fascinating observations:
A single night of sleep deprivation (SD) evoked a strategy shift during risky decision making such that healthy human volunteers moved from defending against losses to seeking increased gains. This change in economic preferences was correlated with the magnitude of an SD-driven increase in ventromedial prefrontal activation as well as by an SD-driven decrease in anterior insula activation during decision making. Analogous changes were observed during receipt of reward outcomes: elevated activation to gains in ventromedial prefrontal cortex and ventral striatum, but attenuated anterior insula activation following losses. Finally, the observed shift in economic preferences was not correlated with change in psychomotor vigilance. These results suggest that a night of total sleep deprivation affects the neural mechanisms underlying economic preferences independent of its effects on vigilant attention.
Blog Categories:
acting/choosing,
fear/anxiety/stress,
sleep
Tuesday, March 29, 2011
A revolution in evolution - cooperation
Milinski reviews Martin Novak's new book "SuperCooperators: Altruism, Evolution, and Why We Need Each Other to Succeed," written with journalist Roger Highfield. (This post is another instance of my passing on some information on a book that I would like very much to read, but never will find time for...).
...evolutionary theorist Martin Nowak sees cooperation as the master architect of evolution. He believes that next to mutation and selection, cooperation is the driving force at every level, from the primordial soup to cells, organisms, societies and even galaxies.Novak shows where the experts disagree, and questions the theoretical basis of kin selection, or inclusive fitness theory. He offers:
Game theory is central to Nowak's work and the book highlights five ways to work together for mutual benefit: direct reciprocity, indirect reciprocity, spatial games, group or multilevel selection and kin selection. Direct reciprocity is the tit-for-tat exchange of resources...Nowak believes that indirect reciprocity, where I help you and someone else helps me, is the most important mechanism driving human sociality. It enforces the power of reputation, gained by helping or refusing help, which is spread through gossip, thus selecting in evolutionary terms for sophisticated language...Cooperators can prevail through exchanges that are played out across and between networks and clusters of individuals...Multilevel or group selection follows among communities that are small, numerous and isolated
...a new model for the evolution of sociality, in which relatedness...is a consequence rather than the cause of social behaviour. By assuming only one mutation — one that causes offspring to stay in the nest rather than leave — he claims to explain why progeny happen to be around to help their related mother.A massive amount of data supporting the idea of kin selection has accumulated, however, and Novak actually says “kin selection is a valid mechanism if properly formulated.”
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