Friday, August 30, 2013
This is a wonderful succinct video that has gone viral, and I would encourage MindBlog readers to have a look at it. I can't imagine a more effective presentation of how connectivity can destroy real community.
A colleague sends me material he finds on longevity, life enhancement, etc. and I thought I would pass on two links on trendy compounds du jour, galantamine and theanine. The magazine on this site offers articles on various compounds suspected to be beneficial and actually lists supporting scientific references. This is a contrast with many sites that hawk some proprietary expensive mixture of amino acids or whatever, with no documentation or journal citations pointing to original research.
Thursday, August 29, 2013
Herbert Benson (of "relaxation response" fame) and collaborators have offered a study suggesting that meditation or relaxation down regulates expression of genes involved in inflammation and HPA stress axis (fight or flight) responses. Beneficial changes in genes regulating mitochondrial energy metabolism and insulin production were also noted. Here is their technical abstract:
The relaxation response (RR) is the counterpart of the stress response. Millennia-old practices evoking the RR include meditation, yoga and repetitive prayer. Although RR elicitation is an effective therapeutic intervention that counteracts the adverse clinical effects of stress in disorders including hypertension, anxiety, insomnia and aging, the underlying molecular mechanisms that explain these clinical benefits remain undetermined. To assess rapid time-dependent (temporal) genomic changes during one session of RR practice among healthy practitioners with years of RR practice and also in novices before and after 8 weeks of RR training, we measured the transcriptome in peripheral blood prior to, immediately after, and 15 minutes after listening to an RR-eliciting or a health education CD. Both short-term and long-term practitioners evoked significant temporal gene expression changes with greater significance in the latter as compared to novices. RR practice enhanced expression of genes associated with energy metabolism, mitochondrial function, insulin secretion and telomere maintenance, and reduced expression of genes linked to inflammatory response and stress-related pathways. Interactive network analyses of RR-affected pathways identified mitochondrial ATP synthase and insulin (INS) as top upregulated critical molecules (focus hubs) and NF-κB pathway genes as top downregulated focus hubs. Our results for the first time indicate that RR elicitation, particularly after long-term practice, may evoke its downstream health benefits by improving mitochondrial energy production and utilization and thus promoting mitochondrial resiliency through upregulation of ATPase and insulin function. Mitochondrial resiliency might also be promoted by RR-induced downregulation of NF-κB-associated upstream and downstream targets that mitigates stress.The second item: Posner and collaborators find that brief meditation training induces smoking reduction
More than 5 million deaths a year are attributable to tobacco smoking, but attempts to help people either quit or reduce their smoking often fail, perhaps in part because the intention to quit activates brain networks related to craving. We recruited participants interested in general stress reduction and randomly assigned them to meditation training or a relaxation training control. Among smokers, 2 wk of meditation training (5 h in total) produced a significant reduction in smoking of 60%; no reduction was found in the relaxation control. Resting-state brain scans showed increased activity for the meditation group in the anterior cingulate and prefrontal cortex, brain areas related to self-control. These results suggest that brief meditation training improves self-control capacity and reduces smoking.
Wednesday, August 28, 2013
A recent article by Benjamin Fong. "Bursting the neuro-utopian bubble" was so widely reported that I have delayed mention of it. In that article he takes on the hubris of some proponents of Obama's "Brain Activity Map Project" that I have mentioned previously. In response to extensive feedback, Fong has issued a clarification of the core of his argument which is worth excerpting here:
One way to present my view would thus be to say that I would like to see a more comprehensive view of scientific inquiry that tames its more “religious” elements, which have gravitated to a particular position that accords the study of the brain a primary importance, and the investigation of psychosocial factors a definitively secondary one...I believe that the $100 million going to the Brain Initiative shows where our priorities lie. We are still far from rectifying a gross imbalance in funding and focus, one that has stemmed, in my view, from an ardent desire for an increasing instrumental control over the world and ourselves.
I attempted to consider two conceptions of scientific inquiry, one of which (science as agent of technological mastery) has come to dominate the other (science as critical examination of our current practices). Drawing on the tradition of critical social theory, I called one “instrumental” and the other “communicative.” My point in distinguishing these two forces was not to give preference to the subordinate party but to argue for the necessity of maintaining a healthy tension between them, especially when it comes to the problem of mental health. I thus heartily agree with many responders that we need both...my concern in the piece was not with “abuses” of science but with the very desire itself and what it unconsciously represses. One does not have to be a psychoanalyst to know that our desires often make us do things of which we are not aware.
In short, it was not my primary intention to argue against the advances of neuroscience, but simply to convey a philosophical wonder about the fact that the idea of changing human physiology — transforming the human being itself — is, at least in some circles, both more “scientific” and more “realistic” than changing human society.
Tuesday, August 27, 2013
A colleague in the chaos seminar group here at the Univ. of Wisconsin sent around this video translating global warming data into a musical piece. I wanted to pass it on to you, because I find it very effective....
I have to pass on this great montage cover and its legend from the journal Neuron. The article referenced described a gene mutation that leads to progressive hearing loss.
The Beethoven mouse, like its namesake the classical music composer Ludwig von Beethoven, suffers progressive hearing loss and eventual profound deafness. In this issue, Pan et al. examined sensory transduction in inner ear hair cells of Beethoven mice, which carry a point mutation in Transmembrane channel-like 1 gene (Tmc1). They report reduced calcium permeability and reduced single-channel conductance in Beethoven hair cells relative to hair cells that expressed wild type Tmc1. The Beethoven data demonstrate that TMC1 is a component of the hair cell transduction channel. The authors found that a closely related homolog, TMC2, also functions as a component of the transduction channel. The image shows Ludwig von Beethoven as portrayed by Joseph Stieler (1820). A cross-section of the ear, including external ear, middle, and inner ear, appears below. Within the inner ear is the spiral-shaped cochlea. The inset below shows the sensory organ, or organ of Corti. At the bottom right is a scanning electron micrograph of a hair bundle from an inner hair cell, which was the main focus of the Pan et al. study. Cover montage by Emily Mills.
Monday, August 26, 2013
Here is a fascinating finding. Not surprising, I suppose, but Telzer et al. show that orphan human infants raised with exposure to only same-race faces (European or Asian) have heightened amygdala responses to out-group faces than those raised with exposure to same- and other-race faces. Later age of adoption is associated with greater biases to race.
In the current study, we investigated how complete infant deprivation to out-group race impacts behavioral and neural sensitivity to race. Although monkey models have successfully achieved complete face deprivation in early life, this is typically impossible in human studies. We overcame this barrier by examining youths with exclusively homogenous racial experience in early postnatal development. These were youths raised in orphanage care in either East Asia or Eastern Europe as infants and later adopted by American families. The use of international adoption bolsters confidence of infant exposure to race (e.g., to solely Asian faces or European faces). Participants completed an emotional matching task during functional MRI. Our findings show that deprivation to other-race faces in infancy disrupts recognition of emotion and results in heightened amygdala response to out-group faces. Greater early deprivation (i.e., later age of adoption) is associated with greater biases to race. These data demonstrate how early social deprivation to race shapes amygdala function later in life and provides support that early postnatal development may represent a sensitive period for race perception.
Thursday, August 22, 2013
I recently did a post pointing to Patricia Marx's article on brain exercises meant to counter aging. The authors went through the training regime of Mike Merzenich's company "Posit Science." I just got the Kindle version of his new book (pub. date July 27, 2013) "Soft Wired - How the new science of brain plasticity can change your life." I got impatient with the excellent presentation of background material in parts I-III of the book that I am familiar with and noted that at the end of each chapter a URL pointed to a bibliography of original articles supporting its statements. On reaching part IV of the book, "The Brain in Retreat," after a brief scan of the text, I ditched reading the book and went straight to the richly annotated gold mine of references. Below, for example, are some slightly edited clips from the references for Chapter 19 "Losing Ground, Just By Having a Birthday! How, more exactly, do mental and physical performance abilities change as we grow older?"...probably more than you wanted to know about how our brains and bodies lose it with aging. I soon found that the references are a work in progress. Detailed literature citations disappear at chapter 22 then reappear with chapter 25, and then trying to pull up references for chapters 32-37 gets a "bad link" message. Both the book and the references detail hassles with getting patents on brain training exercises, forming first one, and then a second company. I would have been happy to be spared this information and would like to have seen some justification why patents and private profits were appropriate for research publicly funded by foundations and the government. I was frustrated by Part V, "Strengthening, correction, and rejuvenation through brain training" because it was mainly a string of homilies on good living, an advertisement for Posit Science, and an account of Merzenich's personal regimes. What about actually explaing a few of the exercises??? The references did give the meat of studies testing the efficacy of various attention, memory, and language exercises. I'm currently looking at some of the free exercises, and may get back to you if I decide to cough up the subscription fee for the whole set and really get into it. Here then are samples from the Merzenich Ch. 19 references:
-Several hundred studies have documented changes in processing speed associated with aging. There are many measured brain process “speeds;” they ALL slow down. See Salthouse TA (2000) Aging and measures of processing speed. Biol Psychol 45:35
-There is one interesting exception: The strength of fast inhibitory processes normally weaken, to the extent that the modulatory response characteristics of neurons in the cortex support faster successive-signal responding (because post-excitatory inhibition is weaker). This change confers no behavioral advantage because the responding in such an inhibition-impaired brain is so noisy that information that comes from signal processing with such degradation declines dramatically. See de Villers-Sidani et al (2010) Recovery of functional and structural age-related changes in the primary auditory cortex with operant training. PNAS 107:13900.
-The extensions of time required to identify successively presented inputs are, on the average, substantially longer in older populations…I identify the MIT professor Jim DiCarlo as making the most convincing arguments that the richer exploration of stimuli via repeated eye movements—more strongly expressed in young vs older individual—is a key to accurate recognition. For example, see DiCarlo JJ et al (2012) How does the brain solve visual object recognition? Neuron 73:415.
-We commonly record correlated changes in representational accuracy and speed in variously impaired (including aging) brains…The less accurate the brain’s neurological representation of what it sees or hears or feels, the longer it takes to “get the answer right,” i.e., to resolve what it is being seen or heard or felt.
-The degradation of our ability to suppress distractors of either external or internal origin with age has been repeatedly documented in behavioral and brain imaging studies; and the susceptibility to distractors has been shown to directly contribute to forgetfulness in older and otherwise-impaired individuals. See, as an introduction to this rapidly growing literature, Gazzaley A, D’Esposito M (2007) Top-down modulation and normal aging. Ann NY Acad Sci 1097:67.
-Many studies have shown that the strength of modulation of brain activity by attention is weaker in most neurologically and psychiatrically impaired populations. That modulation is largely controlled by the release of the neuromodulator acetylcholine. On the statistical average, acetylcholine-based modulation progressively weakens as the decades pass by. For an introduction to this literature, see, for example, Pekkonen E et al (2005) Cholinergic modulation of preattentive auditory processing in aging. Neuroimage 27:387The list goes on: references on contraction of useful field of vision, changes in driving abilities with aging, hearing loss, less vestibular control, less 'executive control'
-For documentation of the multifaceted decline into a more egocentric older life, see, for example, Orth U et al (2010) Tracking the trajectory of shame, guilt and pride across the life span. J Per Soc Psychol 99:1061; or McFarland C et al (1992) Biased recollections in older adults: The role of implicit theories of aging. J Pers Soc Psychol 62:837.
Wednesday, August 21, 2013
Gremel et al. do a nice explication of the brain's upstairs/downstairs story, illustrating with direct electrical recordings how the mouse brain switches between different action strategies (goal-directed and habitual). Goal directed action recruits the frontal cortex while habitual action correlates more with activity in a deeper subcortical structure, the striatum. More indirect imaging data show the story is almost surely same for us. It is the upstairs stuff that is more susceptible to aging, and most of us find it more of an effort to do novel versus habitual actions as we age.
Shifting between goal-directed and habitual actions allows for efficient and flexible decision making. Here we demonstrate a novel, within-subject instrumental lever-pressing paradigm, in which mice shift between goal-directed and habitual actions. We identify a role for orbitofrontal cortex (OFC) in actions following outcome revaluation, and confirm that dorsal medial (DMS) and lateral striatum (DLS) mediate different action strategies. Simultaneous in vivo recordings of OFC, DMS and DLS neuronal ensembles during shifting reveal that the same neurons display different activities depending on whether presses are goal-directed or habitual, with DMS and OFC becoming more and DLS less engaged during goal-directed actions. Importantly, the magnitude of neural activity changes in OFC following changes in outcome value positively correlates with the level of goal-directed behavior. Chemogenetic inhibition of OFC disrupts goal-directed actions, whereas optogenetic activation of OFC specifically increases goal-directed pressing. These results also reveal a role for OFC in action revaluation, which has implications for understanding compulsive behavior.
Tuesday, August 20, 2013
Borjigin et al. make some fascinating observations on brain activity that occurs during the moments of cardiac arrest when brain glucose levels have dropped precipitously. Activity associated with information processing briefly increases 8-fold, a burst even after 'clinical death.' Maybe this is why some patients can recall conversation happening in the operating room.
The brain is assumed to be hypoactive during cardiac arrest. However, the neurophysiological state of the brain immediately following cardiac arrest has not been systematically investigated. In this study, we performed continuous electroencephalography in rats undergoing experimental cardiac arrest and analyzed changes in power density, coherence, directed connectivity, and cross-frequency coupling. We identified a transient surge of synchronous gamma oscillations that occurred within the first 30 s after cardiac arrest and preceded isoelectric electroencephalogram. Gamma oscillations during cardiac arrest were global and highly coherent; moreover, this frequency band exhibited a striking increase in anterior–posterior-directed connectivity and tight phase-coupling to both theta and alpha waves. High-frequency neurophysiological activity in the near-death state exceeded levels found during the conscious waking state. These data demonstrate that the mammalian brain can, albeit paradoxically, generate neural correlates of heightened conscious processing at near-death.
Monday, August 19, 2013
I enjoyed a very well written article by Steven Pinker in the New Republic titled "Science is not your enemy", which argued that an increasing melding of science and the humanities should not be seen at a threat to, but rather as an expansion of, humanistic studies - enhanced by science's quest for intelligibility of the world and a quest for objectivity about its workings. Ross Douthat writes a critique that nails more clearly than I would have the insidious naturalistic fallacy that still lurks in Pinker's prose, the conflating of "is" with "ought to be". He notes that Pinker offers a
...defensible-if-tendentious account of how the progress of science has undercut the world-pictures bequeathed to us by tradition, intuition and religion. Now an innocent reader might assume that the crack-up of these world pictures, with their tight link between cosmic design and human purposes, might make moral consensus more difficult to realistically achieve. After all, if our universe’s testable laws and empirical realities have no experimentally-verifiable connection to human ends and values, then one would expect rival ideas of the good to have difficulty engaging with one another fruitfully, escaping from the pull of relativism or nihilism, and/or grounding their appeals in anything stronger than aesthetic preference.But then cites the following passage from Pinker to point out that isn't where Pinker is going:
In other words, the worldview that guides the moral and spiritual values of an educated person today is the worldview given to us by science. Though the scientific facts do not by themselves dictate values, they certainly hem in the possibilities. By stripping ecclesiastical authority of its credibility on factual matters, they cast doubt on its claims to certitude in matters of morality. … The facts of science, by exposing the absence of purpose in the laws governing the universe, force us to take responsibility for the welfare of ourselves, our species, and our planet. For the same reason, they undercut any moral or political system based on mystical forces, quests, destinies, dialectics, struggles, or messianic ages. And in combination with a few unexceptionable convictions— that all of us value our own welfare and that we are social beings who impinge on each other and can negotiate codes of conduct—the scientific facts militate toward a defensible morality, namely adhering to principles that maximize the flourishing of humans and other sentient beings. This humanism, which is inextricable from a scientific understanding of the world, is becoming the de facto morality of modern democracies, international organizations, and liberalizing religions, and its unfulfilled promises define the moral imperatives we face today.Douthat:
This is an impressively swift march from allowing, grudgingly, that scientific discoveries do not “dictate” values to asserting that they “militate” very strongly in favor of … why, of Steven Pinker’s very own moral worldview! You see, because we do not try witches, we must be utilitarians! Because we know the universe has no purpose, we must imbue it with the purposes of a (non-species-ist) liberal cosmopolitanism! Because of science, we know that modern civilization has no dialectic or destiny … so we must pursue its “unfulfilled promises” and accept its “moral imperatives” instead!Douthat suggest Pinker is promulgating the Whig interpretation of history (from Wikipedia: Whig history ... is the approach to historiography which presents the past as an inevitable progression towards ever greater liberty and enlightenment, culminating in modern forms of liberal democracy and constitutional monarchy. In general, Whig historians emphasize the rise of constitutional government, personal freedoms and scientific progress. The term is often applied generally (and pejoratively) to histories that present the past as the inexorable march of progress toward enlightenment.)
Like Sam Harris, who wrote an entire book claiming that “science” somehow vindicates his preferred form of philosophical utilitarianism (when what he really meant was that if you assume utilitarian goals, science can help you pursue them), Pinker seems to have trouble imagining any reasoning person disagreeing about either the moral necessity of “maximizing human flourishing” or the content of what “flourishing” actually means — even though recent history furnishes plenty of examples and a decent imagination can furnish many more. Like his whiggish antecedents, he mistakes a real-but-complicated historical relationship between science and humanism for a necessary intellectual line in which the latter vindicates the former, or at least militates strongly in its favor.That's the nub of it. What authority does science have to define what "maximizing human flourishing" means?
Friday, August 16, 2013
In my scans of journals' tables of contents for potential MindBlog posts I keep an eye out for articles on exercise, probably the most life enhancing activity one can engage in. A large number of studies document enhancement of learning and memory in animals and people who exercise, and more structure is added to this effect by the study of Schmidt-Kassow et al., that shows that light to moderate physical activity while listening to equivalent nouns in German (familiar language) and Polish (the unfamiliar language) enhances the memorization of the unfamiliar words. Recall two days later was better for this group than for a group sitting quietly before the word presentations or another group that exercised just before the word presentations. Here is their abstract:
Acute physical activity has been repeatedly shown to improve various cognitive functions. However, there have been no investigations comparing the effects of exercise during verbal encoding versus exercise prior to encoding on long-term memory performance. In this current psychoneuroendocrinological study we aim to test whether light to moderate ergometric bicycling during vocabulary encoding enhances subsequent recall compared to encoding during physical rest and encoding after being physically active. Furthermore, we examined the kinetics of brain-derived neurotrophic factor (BDNF) in serum which has been previously shown to correlate with learning performance. We also controlled for the BDNF val66met polymorphism. We found better vocabulary test performance for subjects that were physically active during the encoding phase compared to sedentary subjects. Post-hoc tests revealed that this effect was particularly present in initially low performers. BDNF in serum and BDNF genotype failed to account for the current result. Our data indicates that light to moderate simultaneous physical activity during encoding, but not prior to encoding, is beneficial for subsequent recall of new items.Another study finds a different result for more strenuous exercise during reading for which retention was tested. Exercise decreased retention tested immediately after exercise but after two days retention was the same for exercise and non-exercise groups. Perhaps the low level of physiological arousal in the first study primed the brain for the intake of new information while more vigorous exercise overstimulated and monopolized more of the brain's attentional resources. (This second study had only 11 subjects in the test group, versus 105 used for the first study.)
Wednesday, August 14, 2013
Vohs et al. have done an interesting experiment that suggests that physical order enhances healthy choices, generosity, and conventionality, while disorder correlates with greater creativity. I don't go with their "novel hypothesis" description, but the results describe my partner and myself rather well (I'm the tidy one). The abstract:
Order and disorder are prevalent in both nature and culture, which suggests that each environ confers advantages for different outcomes. Three experiments tested the novel hypotheses that orderly environments lead people toward tradition and convention, whereas disorderly environments encourage breaking with tradition and convention—and that both settings can alter preferences, choice, and behavior. A first experiment showed that relative to participants in a disorderly room, participants in an orderly room chose healthier snacks and donated more money. A second experiment showed that participants in a disorderly room were more creative than participants in an orderly room. A final experiment showed a predicted crossover effect: Participants in an orderly room preferred an option labeled as classic, but those in a disorderly room preferred an option labeled as new. Whereas prior research on physical settings has shown that orderly settings encourage better behavior than disorderly ones, the current research tells a nuanced story of how different environments suit different outcomes.Clips from the text:
Being in a clean room seemed to encourage people to do what was expected of them. Compared with participants in the messy room, they donated more of their own money to charity and were more likely to choose the apple over the candy bar....Being in a messy room led to something that firms, industries, and societies want more of: Creativity...Orderly environments promote convention and healthy choices, which could improve life by helping people follow social norms and boosting well-being. Disorderly environments stimulated creativity, which has widespread importance for culture, business, and the arts.
Tuesday, August 13, 2013
Here is yet another of the increasing number of articles examining the effects of very weak electrical stimulation of our frontal scalp with surface electrodes. I've done a number of posts on this topic, the most recent citing concerns over do it yourself kits now available to anyone. Santarnecchi et al. address the frequency-specific effect of stimulation with the main physiological brain rhythms by comparing performance during four tACS (transcranial alternating current stimulation) conditions — 5 Hz (θ band), 10 Hz (α band), 20 Hz (β band), and 40 Hz (γ band) — and a placebo, sham stimulation. Their summary:
-Online prefrontal γ-tACS selectively accelerated logical reasoning.
-Effects were frequency and task specific
-This contrasts with views of gamma-band activity as a byproduct of neuronal activity
-Gamma-band activity plays a functional role in fluid-intelligence-based reasoning
Everyday problem solving requires the ability to go beyond experience by efficiently encoding and manipulating new information, i.e., fluid intelligence (Gf). Performance in tasks involving Gf, such as logical and abstract reasoning, has been shown to rely on distributed neural networks, with a crucial role played by prefrontal regions. Synchronization of neuronal activity in the gamma band is a ubiquitous phenomenon within the brain; however, no evidence of its causal involvement in cognition exists to date. Here, we show an enhancement of Gf ability in a cognitive task induced by exogenous rhythmic stimulation within the gamma band. Imperceptible alternating current delivered through the scalp over the left middle frontal gyrus resulted in a frequency-specific shortening of the time required to find the correct solution in a visuospatial abstract reasoning task classically employed to measure Gf abilities (i.e., Raven’s matrices). Crucially, gamma-band stimulation (γ-tACS) selectively enhanced performance only on more complex trials involving conditional/logical reasoning. The present finding supports a direct involvement of gamma oscillatory activity in the mechanisms underlying higher-order human cognition.
Left Middle Frontal Gyrus
Monday, August 12, 2013
I have kept a log for many years that has convinced me that I have roughly monthly oscillations in motivation and libido, but I've not come across convincing evidence for roughly lunar or monthly cycles in men in literature searches. So, I perk up on seeing the examination by Cajochen et al. of sleep behavior under highly controlled conditions of a circadian laboratory study protocol without time cues. They find that subjective and objective measures of sleep vary according to lunar periodicity (~29.5 days). Subjects in the study were seventeen healthy young volunteers (nine women and eight men; age range, 20–31 years; mean, 25.0 ± 3.6 years [SD]) and 16 healthy older volunteers (eight women and eight men; age range, 57–74 years; mean, 65.0 ± 5.5 years) Here is their abstract:
Endogenous rhythms of circalunar periodicity (∼29.5 days) and their underlying molecular and genetic basis have been demonstrated in a number of marine species. In contrast, there is a great deal of folklore but no consistent association of moon cycles with human physiology and behavior. Here we show that subjective and objective measures of sleep vary according to lunar phase and thus may reflect circalunar rhythmicity in humans. To exclude confounders such as increased light at night or the potential bias in perception regarding a lunar influence on sleep, we retrospectively analyzed sleep structure, electroencephalographic activity during non-rapid-eye-movement (NREM) sleep, and secretion of the hormones melatonin and cortisol found under stringently controlled laboratory conditions in a cross-sectional setting. At no point during and after the study were volunteers or investigators aware of the a posteriori analysis relative to lunar phase. We found that around full moon, electroencephalogram (EEG) delta activity during NREM sleep, an indicator of deep sleep, decreased by 30%, time to fall asleep increased by 5 min, and EEG-assessed total sleep duration was reduced by 20 min. These changes were associated with a decrease in subjective sleep quality and diminished endogenous melatonin levels. This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues.
Friday, August 09, 2013
An interesting fragment, relating to the powerful vs helplessness theme of a recent post, subjects faced with alternative pain control drugs (both actually placebos) reported better pain relief if they chose the drug rather than having it chosen for them. From Geers et al.:
In modern health care, individuals frequently exercise choice over health treatment alternatives. A growing body of research suggests that when individuals choose between treatment options, treatment effectiveness can increase, although little experimental evidence exists clarifying this effect. Four studies were conducted to test the hypothesis that exercising choice over treatment alternatives enhances outcomes by providing greater personal control. Consistent with this possibility, in Study 1 individuals who chronically desired control reported less pain from a laboratory pain task when they were able to select between placebo analgesic treatments. Study 2 replicated this finding with an auditory discomfort paradigm. In Study 3, the desire for control was experimentally induced, and participants with high desire for control benefited more from a placebo treatment when they were able to choose their treatment. Study 4 revealed that the benefit of choice on treatment efficacy was partially mediated by thoughts of personal control. This research suggests that when individuals desire control, choice over treatment alternatives improves treatment effectiveness by enhancing personal control.
Thursday, August 08, 2013
A well known video shows the famous experiment of missing a gorilla walking through a basketball game when you have been instructed to count the number of times the ball is being passed during playing. (I can not refer you to a free viewing of this video, since the academic who originated it, Dan Simons, has copyrighted it, and aggressively pursues those who might wish to watch it without paying him for a DVD that contain it.) Anyway, an extension of his basic experiment gives you reason to feel even less confident about the expertise of high priced radiologists examining your X-rays. This from Drew et al.:
Researchers have shown that people often miss the occurrence of an unexpected yet salient event if they are engaged in a different task, a phenomenon known as inattentional blindness. However, demonstrations of inattentional blindness have typically involved naive observers engaged in an unfamiliar task. What about expert searchers who have spent years honing their ability to detect small abnormalities in specific types of images? We asked 24 radiologists to perform a familiar lung-nodule detection task. A gorilla, 48 times the size of the average nodule, was inserted in the last case that was presented. Eighty-three percent of the radiologists did not see the gorilla. Eye tracking revealed that the majority of those who missed the gorilla looked directly at its location. Thus, even expert searchers, operating in their domain of expertise, are vulnerable to inattentional blindness.
Wednesday, August 07, 2013
A piece like this one by Oechslin et al. gives me some hope that my piano playing and sight reading compensate for my aversion to spending any significant amount of time on anti-aging brain exercise regimes of the sort described in a recent post. Hopefully, if I keep up my piano playing as I age, I will be going ga-ga later rather than sooner. The abstract:
Using functional magnetic resonance imaging, we show for the first time that levels of musical expertise stepwise modulate higher order brain functioning. This suggests that degree of training intensity drives such cerebral plasticity. Participants (non-musicians, amateurs, and expert musicians) listened to a comprehensive set of specifically composed string quartets with hierarchically manipulated endings. In particular, we implemented 2 irregularities at musical closure that differed in salience but were both within the tonality of the piece (in-key). Behavioral sensitivity scores (d′) of both transgressions perfectly separated participants according to their level of musical expertise. By contrasting brain responses to harmonic transgressions against regular endings, functional brain imaging data showed compelling evidence for stepwise modulation of brain responses by both violation strength and expertise level in a fronto-temporal network hosting universal functions of working memory and attention. Additional independent testing evidenced an advantage in visual working memory for the professionals, which could be predicted by musical training intensity. The here introduced findings of brain plasticity demonstrate the progressive impact of musical training on cognitive brain functions that may manifest well beyond the field of music processing.
Tuesday, August 06, 2013
Banakou et al. show that if we use some simple tricks to project ourselves into a 4-year old's body, we overestimate object sizes and more readily associate ourselves with child-like attributes:
An illusory sensation of ownership over a surrogate limb or whole body can be induced through specific forms of multisensory stimulation, such as synchronous visuotactile tapping on the hidden real and visible rubber hand in the rubber hand illusion. Such methods have been used to induce ownership over a manikin and a virtual body that substitute the real body, as seen from first-person perspective, through a head-mounted display. However, the perceptual and behavioral consequences of such transformed body ownership have hardly been explored. In the first experiment, immersive virtual reality was used to embody 30 adults as a 4-y-old child (condition C), and as an adult body scaled to the same height as the child (condition A), experienced from the first-person perspective, and with virtual and real body movements synchronized. The result was a strong body-ownership illusion equally for C and A. Moreover there was an overestimation of the sizes of objects compared with a nonembodied baseline, which was significantly greater for C compared with A. An implicit association test showed that C resulted in significantly faster reaction times for the classification of self with child-like compared with adult-like attributes. A second experiment with an additional 16 participants extinguished the ownership illusion by using visuomotor asynchrony, with all else equal. The size-estimation and implicit association test differences between C and A were also extinguished. We conclude that there are perceptual and probably behavioral correlates of body-ownership illusions that occur as a function of the type of body in which embodiment occurs.
Experimental setup. The body of the participant was substituted by a sex-matched virtual body, viewed from first-person perspective, onto which body and head movements were mapped in real time. The body could also be seen as reflected in a virtual mirror as shown. The body each participant viewed depended on the condition C (for child) or A (for adult) to which each one was assigned. (A) A female participant in a child’s body. (B) A female participant in a scaled-down adult’s body. (C) Participants’ body movements were tracked by 34 Optitrack markers.
Monday, August 05, 2013
Velasquez-Manoff does a nice discussion of a topic that has been recurrent in MindBlog, understanding the kind of stress that is really bad for us. Not the stress that goes with daily personal and professional aggravations, but the long term stress that derives from feeling helpless to control our lives. Numerous studies, the best known being a long term study of British civil servants, have shown that being higher in a social hierarchy correlates with having better health. The sense of control:
...tends to decline as one descends the socioeconomic ladder, with potentially grave consequences. Those on the bottom are more than three times as likely to die prematurely as those at the top. They’re also more likely to suffer from depression, heart disease and diabetes. Perhaps most devastating, the stress of poverty early in life can have consequences that last into adulthood.The article quotes Robert Sapolsky at Stanford, whose classic book "Why Zebras Don't Get Ulcers" is still a must read, as saying:
Early-life stress and the scar tissue that it leaves, with every passing bit of aging, gets harder and harder to reverse...You’re never out of luck in terms of interventions, but the longer you wait, the more work you’ve got on your hands.Bruce McEwen and others talk about
...the “biological embedding” of social status. Your parents’ social standing and your stress level during early life change how your brain and body work, affecting your vulnerability to degenerative disease decades later. They may even alter your vulnerability to infection. In one study, scientists at Carnegie Mellon exposed volunteers to a common cold virus. Those who’d grown up poorer (measured by parental homeownership) not only resisted the virus less effectively, but also suffered more severe cold symptoms.Another clip:
Animal studies help dispel doubts that we’re really seeing sickly and anxiety-prone individuals filter to the bottom of the socioeconomic heap. In primate experiments females of low standing are more likely to develop heart disease compared with their counterparts of higher standing. When eating junk food, they more rapidly progress toward heart disease. The lower a macaque is in her troop, the higher her genes involved in inflammation are cranked. High-ranking males even heal faster than their lower-ranking counterparts. Behavioral tendencies change as well. Low-ranking males are more likely to choose cocaine over food than higher-ranking individuals.Finally:
...while Americans generally gained longevity during the late 20th century, those gains have gone disproportionately to the better-off. Those without a high school education haven’t experienced much improvement in life span since the middle of the 20th century. Poorly educated whites have lost a few years of longevity in recent decades.
A National Research Council report, meanwhile, found that Americans were generally sicker and had shorter life spans than people in 16 other wealthy nations. We rank No. 1 for diabetes in adults over age 20, and No. 2 for deaths from coronary artery disease and lung disease. The Japanese smoke more than Americans, but outlive us — as do the French and Germans, who drink more. The dismal ranking is surprising given that America spends nearly twice as much per capita on health care as the next biggest spender.
Friday, August 02, 2013
Happiness is usually classified into two main flavors: hedonic and eudaimonic. Hedonic refers mainly to self gratification and eudaimonic to a sense of meaning and purpose beyond that. In a study involving 80 healthy adult subjects, Fredrickson et al. used a questionnaire to asses levels of hedonic and eudaimonic happiness (questions such as 'over the last week, how often did you feel happy or satisfied? (hedonic); or, 'how often in the last week did you feel your life has a sense of purpose, meaning or direction?' (eudaimonic). They also looked at expression of genes associated with immune system responses. The fascinating result was that hedonic happiness correlated with higher expression of genes typically activated by extended periods of stress, activity that increases inflammation and decreases antiviral responses. Higher Eudaimonic happiness correlated with lower activation levels of these genes and strengthened immune function.
Both kinds of happiness make us "feel good." The central point is that our genome may be "more sensitive to qualitative variations in well-being than are our conscious affective experiences." Here is their abstract:
Both kinds of happiness make us "feel good." The central point is that our genome may be "more sensitive to qualitative variations in well-being than are our conscious affective experiences." Here is their abstract:
To identify molecular mechanisms underlying the prospective health advantages associated with psychological well-being, we analyzed leukocyte basal gene expression profiles in 80 healthy adults who were assessed for hedonic and eudaimonic well-being, as well as potentially confounded negative psychological and behavioral factors. Hedonic and eudaimonic well-being showed similar affective correlates but highly divergent transcriptome profiles. Peripheral blood mononuclear cells from people with high levels of hedonic well-being showed up-regulated expression of a stress-related conserved transcriptional response to adversity (CTRA) involving increased expression of proinflammatory genes and decreased expression of genes involved in antibody synthesis and type I IFN response. In contrast, high levels of eudaimonic well-being were associated with CTRA down-regulation. Promoter-based bioinformatics implicated distinct patterns of transcription factor activity in structuring the observed differences in gene expression associated with eudaimonic well-being (reduced NF-κB and AP-1 signaling and increased IRF and STAT signaling). Transcript origin analysis identified monocytes, plasmacytoid dendritic cells, and B lymphocytes as primary cellular mediators of these dynamics. The finding that hedonic and eudaimonic well-being engage distinct gene regulatory programs despite their similar effects on total well-being and depressive symptoms implies that the human genome may be more sensitive to qualitative variations in well-being than are our conscious affective experiences.