MRI can decode subjective, but not objective, memories

In experiments that cast further doubt on claims of lie detection by fMRI measurements, Rissman et al. find that subjective memory states can be decoded accurately under controlled experimental conditions, but that fMRI has uncertain utility for objectively detecting an individual's past experiences. Here is a nice summary of their work from Gilbert Chin:

As a consequence of recent investigations that have used sophisticated methods of analyzing brain activity to propose that objective lie detection may be feasible, it has become apparent that designing a task in which subjects lie whole-heartedly and voluntarily (as opposed to being instructed to do so every fifth answer, for instance) is a nontrivial undertaking. Rissman et al. have approached this challenge by adapting a well-established laboratory paradigm—that of face recognition—to conditions that approximate those of quotidian experience. They asked subjects to study 200 faces and then interrogated them 1 hour later, using a mix of new and old test faces. The menu of responses offered a choice of (i) definitely remembered; (ii–iii) high and low confidence that the face was familiar; and (iv–v) high and low confidence that the face was new.

An analysis of brain activity during the response phase revealed distinctive patterns when old (that is, previously studied) faces were rated by the subject as definitely remembered versus strongly familiar, and also when they were rated as being strongly versus weakly familiar. In contrast, for faces rated as being weakly unfamiliar, it was not possible to tell from the neural activity patterns which were actually new and which had been seen during the study phase, and for weakly familiar faces, the new/old distinction was achievable only some of the time. Furthermore, if subjects were instead told to rate attractiveness during the study phase and then asked to categorize faces by gender during the response phase, it was not possible to diagnose which faces were new and which were not. Taken together, these findings suggest that brain activity reflects subjective, rather than objective, face recognition.

How we read the minds of others.

Tamir et al. do some interesting MRI studies that suggest that understanding the mental states of others starts with self perception as an anchor from which serial adjustments of the perceptions of others are made:

Recent studies have suggested that the medial prefrontal cortex (MPFC) contributes both to understanding the mental states of others and to introspecting about one's own mind. This finding has suggested that perceivers might use their own thoughts and feelings as a starting point for making inferences about others, consistent with “simulation” or “self-projection” views of social cognition. However, perceivers cannot simply assume that others think and feel exactly as they do; social cognition also must include processes that adjust for perceived differences between self and other. Recent cognitive work has suggested that such correction occurs through a process of “anchoring-and-adjustment” by which perceivers serially tune their inferences from an initial starting point based on their own introspections. Here, we used functional MRI to test two predictions derived from this anchoring-and-adjustment view. Participants (n = 64) used a Likert scale to judge the preferences of another person and to indicate their own preferences on the same items, allowing us to calculate the discrepancy between the participant's answers for self and other. Whole-brain parametric analyses identified a region in the MPFC in which activity was related linearly to this self–other discrepancy when inferring the mental states of others. These findings suggest both that the self serves as an important starting point from which to understand others and that perceivers customize such inferences by serially adjusting away from this anchor.

Figure - The relation between BOLD response and self–other discrepancy during Other trials was calculated separately for subregions of the MPFC. Although the response of dorsal MPFC (A) increased linearly with increasing self–other discrepancy, the response of ventral MPFC (B) distinguished only between trials on which self–other discrepancy was zero (overlap between self and other) versus greater than zero (discrepancy between self and other). Error bars indicate the SEM.

A bit more on the actual experimental design:

Although the specific design of the four experiments differed slightly, each required participants to answer a series of questions about their opinions and preferences and to judge how other individuals would answer the same questions. On each trial, participants saw a cue that indicated the target of the judgment (self or another person) and a brief phrase (e.g., “enjoy winter sports such as skiing or snowboarding”; “fear speaking in public”). Participants used either a four- or five-point scale either to report how well the statement described themselves or to judge how well it described the other person. Within each experiment, participants considered the same set of statements for self and other.

Before scanning, participants were told that the purpose of the experiment was to examine how people make inferences about target individuals on the basis of minimal or no information. In all studies, targets were college-aged individuals depicted by a photograph downloaded from an internet dating website, although the specific identity of individuals varied across studies.

"The Singularity" - and Singularity University

I've been meaning to point to this interesting New York Times article, on techno-utopian Singularity University (whose sponsors include Google co-founders Sergey Brin and Larry Page), which aims to enhance and prepare us for the arrival of "The Singularity" — "a time, possibly just a couple decades from now, when a superior intelligence will dominate and life will take on an altered form that we can’t predict or comprehend in our current, limited state." The article focuses on Raymond Kurzweil, the inventor and businessman who is the Singularity’s most ubiquitous spokesman:

...(who, in August)..will begin a cross-country multimedia road show to promote “Transcendent Man,” a documentary about his life and beliefs. Another of his projects, “The Singularity Is Near: A True Story About the Future,” has also started to make its way around the film festival circuit....some Singularitarians aren’t all that fond of Mr. Kurzweil...“I think he’s a genius and has certainly brought a lot of these ideas into the public discourse,” says James J. Hughes, the executive director of the Institute for Ethics and Emerging Technologies, a nonprofit that studies the implications of advancing technology. “But there are plenty of people that say he has hijacked the Singularity term.”

Some of the Singularity’s adherents portray a future where humans break off into two species: the Haves, who have superior intelligence and can live for hundreds of years, and the Have-Nots, who are hampered by their antiquated, corporeal forms and beliefs....“The Singularity is not the great vision for society that Lenin had or Milton Friedman might have,” says Andrew Orlowski, a British journalist who has written extensively on techno-utopianism. “It is rich people building a lifeboat and getting off the ship.”

Despite all of the zeal behind the movement, there are those who look askance at its promises and prospects...Jonathan Huebner, for example, is often held up as Mr. Kurzweil’s foil. A physicist who works at the Naval Air Warfare Center as a weapons designer, he, like Mr. Kurzweil, has compiled his own cathedral of graphs and lists of important inventions. He is unimpressed with the state of progress and, in 2005, published in a scientific journal a paper called “A Possible Declining Trend for Worldwide Innovation.”..Measuring the number of innovations divided by the size of the worldwide population, Dr. Huebner contends that the rate of innovation peaked in 1873. Or, based on the number of patents in the United States weighed against the population, he found a peak around 1916. (Both Dr. Huebner and Mr. Kurzweil are occasionally teased about their faith in graphs.)

Presidential Harrisment

A clip from an article by Steve Mirsky in the June issue of Scientific American:

In early March, Harris Interactive conducted an on-line survey to gauge the attitudes of Americans toward President Barack Obama. The Harris Poll generated some fascinating data. For example, 40 percent of those polled believe Obama is a socialist. (He’s not—ask any socialist.) Thirty-two percent believe he is a Muslim. (I had predicted that a Mormon, Jew, Wiccan, atheist and Quetzalcoatl worshipper would become president before America elected a Muslim, so a third of this country actually may be quite open-minded, in an obtuse way.) Also, 14 percent believe that Obama may be the Antichrist. Of those who identified themselves as Republicans, 24 percent think Obama might be.

Concert pianists as genius models?

Not likely in my case.... but I will mention an article by Charles Ambrose in the July-August issue of American Scientist, pointed out to me by a friend who is a loyal MindBlog reader. I started this blog post at the same time I plunged into read the article, assuming I would be passing on some juicy clips, but alas have to report coming up short of much substance - although the article is worth a link because of its review of brain plasticity, and notes specific brain changes associated with development of various skilled activities. Ambrose mentions the increased areas in the parietal lobe found in Albert Einstein's brain, and then goes on to note other examples of increases in brain areas associated with expertise, as for example in professional musicians who have enlarged areas in their auditory cortex. The article doesn't even begin to engage the teaser sentence at its beginning: "What accounts for highly intelligent and greatly gifted individuals?" and is disjointed and wandering enough that I'm surprised that editors at American Scientist let it through their filters.

Antipsychotic drug shrinks the brain

It turns out that haloperidol, a commonly-prescribed antipsychotic drug, shrinks the brain within hours of administration, specifically diminishing grey-matter volume in the striatum — a region that mediates movement. The effect is reversible. The Meyer-Lindberg group doing the study suggests that by acting on Dopamine D2 receptors it may downsize synaptic connections, and thus cause the lapses in motor control that affect many patients on antipsychotics.

Sense of Wonder

As we age our brains become so stuffed with our history that we loose the capacity to open to novel experiences, to sense things with the naive freshness of a child. I pass on this brief fable by Richard A. Lovett in the June 3 Issue of Nature about a miraculous cure for this condition:

Clay Nadir wanted a book for the beach. Not just any book, but the type that makes you forget the beach, other than as the place where you discovered Jack London or Sherlock Holmes or Norman Mailer. But even on the shelves of his city's largest bookstore, he wasn't finding anything. It was as though everything new had long ago been stuffed into his brain.

Maybe he was jaded. Maybe, once you'd worked your way through Agatha Christie, no manor house would ever again hold your attention. And was The Time Machine really that good, or had it simply been a first, both for Clay and the world?

Nature writing, westerns, mountaineering, ghost stories, dysfunctional families ... literarily, Clay had been there, done that. In the past hour he'd wandered though fantasy, mystery, biography and what a friend called 'Qual. Lit.' — a conceited term if ever there was one. Quality literature, ha! As though any genre had a monopoly. Not to mention that once you'd read Nabokov and Woolf and Joyce, you could get as jaded with that stuff as anything else. Even Shakespeare you could eventually memorize.

Maybe he should try romance. He'd never dabbled in it before, so at least it would be different.

Then, in the occult section, something caught his eye. It was an odd book: black, with a red, spiral vortex on the cover. It made him think of Hitchcock's Vertigo. Now that was a movie: Jimmy Stewart and Kim Novak in a deceptively simple story you had to see several times to fully grasp. But once you did, so many other movies seemed so ... trivial.

The book also made him think of something from his youth. Something to do with an old TV show. What was it called? Oh yes, The Time Tunnel. Each week, they'd spun this thing like a giant pinwheel and run off to some distant era. Probably unbelievably stupid if he watched it today, but at the time it hit him like his first viewing of Doctor Who, another show involving a time vortex, plus a lot of other things he'd never seen before.

There was no author listed, and as he picked up the book, he seemed to be falling into the vortex. On the back was a simple endorsement: 'Guaranteed to restore your sense of wonder'.

Yeah, right. He'd heard that one before.

He opened it but there was no preface, no introduction, no writing at all. Just more spirals, one to a page, these in black-and-white.

He nearly set it back down, but the sense of being sucked in was too strong. It was as though the entire room were spinning: just what Jimmy Stewart's character must have felt as he looked into the depths ... Dizzying enough that Clay no longer wanted to think about Stewart or Hitchcock or old TV shows.

There was a white circle in the centre of the first spiral. Peering into it he saw flickers of motion: barely remembered images of Jimmy Stewart, Kim Novak and maybe The Time Tunnel.

With an effort, he turned the page. Another spiral, again sucking him in. This time, he saw words.

Call me Ishmael.

It was the best of times ...

In the beginning God created the heavens and earth.

Once upon a time there was a Martian named Valentine Michael Smith.

To be, or not to be ...

Rather than simply reading them, he felt as though the words were being pulled from him, faster and faster. He turned another page and another and another. It wasn't just words and videos. There were also stills: a stern-looking couple with a pitchfork; a woman with an odd half-smile. Guitar riffs, symphonies, something about Lucy in the sky with a yellow submarine. Names for these would tickle his memory then be gone, often faster than he could grasp what they had been. Something about whistling and moaning. Something about singing insects.

Then, it was over. Clay had no idea how long he'd been staring at the book. All he knew was that he'd flipped through most of the pages, but not all. He looked at the next few, but they were simply spirals. Still dizzying, but not like before. He flipped back, but there were no longer any words or images. Just paper.

There was no price tag on the book. Clay wondered briefly why it had been so captivating. Maybe he'd merely let his blood sugar dip too low. Maybe the spirals caught him off guard.

He put the book back where he'd found it, on a countertop beside a computer terminal where customers could check the store's inventory. It was as though a prior reader, if that was the proper term for the peruser of such a book, had placed it there, easy to find.

Clay still needed something for the beach.

He wandered the store, more or less at random, until he fetched up in the mystery section. Mysteries were fun, he thought, although he didn't know why. There were a lot of books and he couldn't remember which ones he'd read, so he picked the first that caught his eye.

'It was a dark and stormy night,' he read. Wow, he breathed, and was instantly hooked.

The Devil's grimmace.

An interesting fragment by Gisela Telis in ScienceNow:

When 15th-century Europeans first landed on the Bahamas, Cuba, and Hispaniola, they met with the "devil's grimace." That's what these foreigners dubbed the faces with bared teeth that adorned everything from necklaces to ceremonial bowls created by the native Taíno people. European chroniclers interpreted the motif as a ferocious animal's snarl or a skull's grimace, signs of the heathen islanders' aggression. But they were wrong, researchers report in the latest issue of Current Anthropology. By studying teeth-baring in humans, chimps, and rhesus macaques and comparing these to the Taíno depictions, scientists determined that open-lipped, closed-jaw displays show submission, benign intent, and even happiness—but not aggression. So the "fiendish" faces that so troubled Europeans were most likely just smiling, to signal—ironically enough—social cohesion and connection.

Oxytocin: out-group aggression, social cues, and amygdalar action

Three recent papers are a reflection of the recent outpouring of work on oxytocin (a peptide hormone containing the 9 amino acids shown in the figure), which (from Miller's review):

...promotes social bonding in a wide range of animals, including humans. Sold on the Internet in a formulation called "Liquid Trust," the peptide hormone is marketed as a romance enhancer and sure ticket to business success. Australian therapists are trying it alongside counseling for couples with ailing marriages. And police and military forces reportedly are interested in its potential to elicit cooperation from crime suspects or enemy agents.

The hormone is now being found to have a prickly side, and is coming to be regarded as much more than just a touchy-feely "trust hormone." De Dreu et al. have designed experiments to demonstrate that oxytocin drives a "tend and defend" response in that it promotes in-group trust and cooperation, and defensive, but not offensive, aggression toward competing out-groups.

In another study on oxytocin, Gamer et al. add to studies that have shown that oxytocin decreases aversive reactions to negative social stimuli, and find that subjects given oxytocin, relative to subjects given placebo, are more likely to make eye movements toward the eye region when viewing images of human faces. They find that subregions of the amygdala are important in mediating this effect. Oxytocin:

...attenuated activation in lateral and dorsal regions of the anterior amygdala for fearful faces but enhanced activity for happy expressions, thus indicating a shift of the processing focus toward positive social stimuli. On the other hand, oxytocin increased the likelihood of reflexive gaze shifts toward the eye region irrespective of the depicted emotional expression. This gazing pattern was related to an increase of activity in the posterior amygdala and an enhanced functional coupling of this region to the superior colliculi. Thus, different behavioral effects of oxytocin seem to be closely related its specific modulatory influence on subregions within the human amygdala.

These finding have implications for understanding the role of oxytocin in normal social behavior as well as the possible therapeutic impact of oxytocin in brain disorders characterized by social dysfunction.

The Wayward Mind

Continuing my review of old posts that have popped into my head over the past few days during mulling over this and that, I am reproducing my March 6, 2006 post in its entirety: 

I want to mention the excellent book by Guy Claxton - THE WAYWARD MIND, an intimate history of the unconscious (2005, Little, Brown, and Co., available from amazon.com). Here is a excerpt and paraphrase from pp. 348-252:

"What we call our "self " is an agglomeration of both conscious and unconscious ingredients, cans, needs, dos, oughts, thinks - the temptation is to assume that the "I" is the same in all of them - so that instead of having an intricate web of things that make me ME, I have to create a single imaginary hub around which they all revolve, to which they all refer - the attempt to keep this fiction going, to "hold it together" can become quite tiring and bothersome - If "I" am essentially reasonable, if I imagine that my zones of control - over my own feelings for example - are wider and more robust than they are, then I am going to get in a tangle trying to "control myself." If I have decided that who I am is clever, attractive, athletic, stable, creating the hub of "I" locks everything together and prevents it moving. It stops Me expanding to include the unconscious, or graciously shrinking to accommodate old age. I can not enjoy my waywardness, nor see it as an intrinsic part of ME - (note: he gives Ramachandran's two foot nose pinocchio demonstration as evidence of plasticity of self image), and then says - The orthodox sense of self is thrown by such experiences, and tends to suffer a sense-of-humour failure. It sees all waywardness as an affront, and tends to become earnest or myopic in response. In a nutshell: it is bad enough to have a nightmare, without your rattled sense of self telling you that you are going mad. Weird experience can never be just funny (as the pinocchio effect can be) or matter-of fact (as possession is in Bali), or transiently inconvenvient (as a bad dream is), or wonderful (as a mystical experience can be), or just mysterious (as a premonition might be). For the locked-up self they have to be denied, explained or dealt with. All the evidence is that a more relaxed attitude toward the bounds of self makes for a richer, easier and more creative life. Perhaps, after all, waywardness in all its forms is in need not so much of explanation, but of a mystified but friendly welcome. We can explain it if we wish, and the brain is beginning to a reasonable job. But the need to explain, when not motivated by the dispassionate curiosity of the scientist, is surely a sign of anxiety: of the desire to tame with words that which is experienced as unsettling.

Followup on acupuncture

Following the "Acupuncture's secret revealed?" post on 6/17 a reader sent me two interesting links that I want to pass on.  Body in Mind reviews a paper in Journal of Pain that finds no significant effect of physician training or expertise on outcome, and notes studies that find no difference between needle placement at classical acupuncture points and randomly placed needles, and also that patient expectations about acupuncture influence outcome. And, Eric Mead briefly lectures on "The Magic of the Placebo."

Is life worth living?

Philosopher Peter Singer, in his "Should this be the last generation" query, offers philosophical rambling of the sort that drives me up the wall, a prime example of one of the things our brains were definitely not designed to do. My bottom line is that I refuse to get excited about existential issues ("Is life worth living", etc.) beyond those I think my two abyssinian cats would find compelling...food, shelter, a place to poop, and sex. I don't think the human overlay on top of that has shown much competence with  'the meaning of it all' questions. In this territory we are like the dog being asked to understand quantum physics. Singer starts by noting 19th century German philosopher Schopenhauer's pessimism:

...the best life possible for humans is one in which we strive for ends that, once achieved, bring only fleeting satisfaction. New desires then lead us on to further futile struggle and the cycle repeats itself.

He then goes on to note more recent arguments from philosopher David Benatar:

To bring into existence someone who will suffer is, Benatar argues, to harm that person, but to bring into existence someone who will have a good life is not to benefit him or her...Hence continued reproduction will harm some children severely, and benefit none.

Benatar also argues that human lives are, in general, much less good than we think they are....we are, in Benatar’s view, victims of the illusion of pollyannaism. This illusion may have evolved because it helped our ancestors survive, but it is an illusion nonetheless. If we could see our lives objectively, we would see that they are not something we should inflict on anyone.

...the people who will be most severely harmed by climate change have not yet been conceived. If there were to be no future generations, there would be much less for us to feel to guilty about....So why don’t we make ourselves the last generation on earth? If we would all agree to have ourselves sterilized then no sacrifices would be required — we could party our way into extinction!

Singer does end on a more upbeat note:

I do think it would be wrong to choose the non-sentient universe. In my judgment, for most people, life is worth living. Even if that is not yet the case, I am enough of an optimist to believe that, should humans survive for another century or two, we will learn from our past mistakes and bring about a world in which there is far less suffering than there is now. But justifying that choice forces us to reconsider the deep issues with which I began. Is life worth living? Are the interests of a future child a reason for bringing that child into existence? And is the continuance of our species justifiable in the face of our knowledge that it will certainly bring suffering to innocent future human beings?

Are you holding your breath?

While mulling over how I am feeling or acting during the day,  a recollection of an old MindBlog post occasionally pops into my head....I sometimes go back and look at that post, find it useful, and think it might be worth repeating. I think I will act on this impulse now, and more frequently in the future.  Here is a repeat of the entirety of a post from Jan. 28, 2008:


I notice - if I am maintaining awareness of my breathing - that the breathing frequently stops as I begin a skilled activity such as piano or computer keyboarding. At the same time I can begin to sense an array of unnecessary (and debilitating) pre-tensions in the muscle involved. If I just keep breathing and noticing those tensions, they begin to release. (Continuing to let awareness return to breathing when it drifts is a core technique of mindfulness meditation). Several sources note that attending to breathing can raise one's general level of restfulness relative to excitation, enhancing parasympathetic (restorative) over sympathetic (arousing) nervous system activities. These personal points make me feel like passing on some excerpts from a recent essay which basically agrees with these points: "Breathtaking New Technologies," by Linda Stone, a former Microsoft VP and Co-Founder and Director of Microsoft's Virtual Worlds Group/Social Computing Group. It is a bit simplistic, but does point in a useful direction.

I believe that attention is the most powerful tool of the human spirit and that we can enhance or augment our attention with practices like meditation and exercise, diffuse it with technologies like email and Blackberries, or alter it with pharmaceuticals...but... the way in which many of us interact with our personal technologies makes it impossible to use this extraordinary tool of attention to our advantage...the vast majority of people hold their breath especially when they first begin responding to email. On cell phones, especially when talking and walking, people tend to hyper-ventilate or over-breathe. Either of these breathing patterns disturbs oxygen and carbon dioxide balance...breath holding can contribute significantly to stress-related diseases. The body becomes acidic, the kidneys begin to re-absorb sodium, and as the oxygen and CO2 balance is undermined, our biochemistry is thrown off.

The parasympathetic nervous system governs our sense of hunger and satiety, flow of saliva and digestive enzymes, the relaxation response, and many aspects of healthy organ function. Focusing on diaphragmatic breathing enables us to down regulate the sympathetic nervous system, which then causes the parasympathetic nervous system to become dominant. Shallow breathing, breath holding and hyper-ventilating triggers the sympathetic nervous system, in a "fight or flight" response...Some breathing patterns favor our body's move toward parasympathetic functions and other breathing patterns favor a sympathetic nervous system response. Buteyko (breathing techniques developed by a Russian M.D.), Andy Weil's breathing exercises, diaphragmatic breathing, certain yoga breathing techniques, all have the potential to soothe us, and to help our bodies differentiate when fight or flight is really necessary and when we can rest and digest.

I've changed my mind about how much attention to pay to my breathing patterns and how important it is to remember to breathe when I'm using a computer, PDA or cell phone...I've discovered that the more consistently I tune in to healthy breathing patterns, the clearer it is to me when I'm hungry or not, the more easily I fall asleep and rest peacefully at night, and the more my outlook is consistently positive...I've come to believe that, within the next 5-7 years, breathing exercises will be a significant part of any fitness regime.

Associating a nerve growth factor with positive affect - depression therapy?

Panksepp has made a number of interesting observations on the neurochemistry of affiliative (bonding) and hedonic behavior in animals (role of dopamine, etc). Now attention turns to nerve growth factors. Here is the abstract from a recent collaboration:

Positive emotional states have been shown to confer resilience to depression and anxiety in humans, but the molecular mechanisms underlying these effects have not yet been elucidated. In laboratory rats, positive emotional states can be measured by 50-kHz ultrasonic vocalizations (hedonic USVs), which are maximally elicited by juvenile rough-and-tumble play behavior. Using a focused microarray platform, insulin-like growth factor I (IGFI) extracellular signaling genes were found to be upregulated by hedonic rough-and-tumble play but not depressogenic social defeat. Administration of IGFI into the lateral ventricle increased rates of hedonic USVs in an IGFI receptor (IGFIR)-dependent manner. Lateral ventricle infusions of an siRNA specific to the IGFIR decreased rates of hedonic 50-kHz USVs. These results show that IGFI plays a functional role in the generation of positive affective states and that IGFI-dependent signaling is a potential therapeutic target for the treatment of depression and anxiety.

Is that my Mobile ringing? Rapid brain processing

Roye et al. show that top-down frontal-parietal attentional mechanisms prime even the earliest stages of our auditory pathways to be especially sensitive to personally significant sounds:

Anecdotal reports and also empirical observations suggest a preferential processing of personally significant sounds. The utterance of one's own name, the ringing of one's own telephone, or the like appear to be especially effective for capturing attention. However, there is a lack of knowledge about the time course and functional neuroanatomy of the voluntary and the involuntary detection of personally significant sounds. To address this issue, we applied an active and a passive listening paradigm, in which male and female human participants were presented with the SMS ringtone of their own mobile and other's ringtones, respectively. Enhanced evoked oscillatory activity in the 35–75 Hz band for one's own ringtone shows that the brain distinguishes complex personally significant and nonsignificant sounds, starting as early as 40 ms after sound onset. While in animals it has been reported that the primary auditory cortex accounts for acoustic experience-based memory matching processes, results from the present study suggest that in humans these processes are not confined to sensory processing areas. In particular, we found a coactivation of left auditory areas and left frontal gyri during passive listening. Active listening evoked additional involvement of sensory processing areas in the right hemisphere. This supports the idea that top-down mechanisms affect stimulus representations even at the level of sensory cortices. Furthermore, active detection of sounds additionally activated the superior parietal lobe supporting the existence of a frontoparietal network of selective attention.

Acupuncture's secret revealed?

I've tried acupuncture therapy for myself, and found it to be somewhere between ineffective and mildly annoying. This experience, plus reading several convincing studies finding identical pain reduction effects when acupuncture was compared with sham or placebo manipulations has made me think it likely that acupuncture is in fact a placebo effect. Now Goldman et al. have found a greater than 20-fold increase in adenosine, a nerve modulator with anti-nociceptive (i.e. anti-pain) properties, in tissue around the point where  acupuncture needles are rotated in a mouse's paw. This reduces pain in the paw caused by an injected inflamatory chemical, and the effect is not observed in mice genetically altered to delete the pain nerve adenosine receptors. An adenosine receptor agonist (enhancer) boosts the effectiveness of the acupuncture treatment.

Now, what one needs to see next is experiments with humans in which adenosine release caused by rotating a needle at the classical acupuncture needle points is measured and compared with the release at randomly placed needles.  Also, it would be interesting to see whether other placebo interventions shown to cause endorphin release also caused adenosine release.

Cognitive changes caused by single exposure to a placebo

Given the mention of placebo responses in today's other post on acupuncture, I thought I would pass on this interesting bit in Neuropsychologia from Morton et al., showing that the cognitive effects of a single placebo intervention can persist for six weeks:

Placebo has been shown to be a powerful analgesic with corresponding reduction in the activation of the pain matrix in the brain. However, the response to placebo treatment is highly variable. It is unclear how anticipatory and pain-evoked potentials are affected by the treatment and how reproducible the response is. Laser stimulation was used to induce moderate pain in healthy volunteers. We induced placebo analgesia by conditioning subjects to expect pain reduction by applying a sham anaesthetic cream on one arm in conjunction with a reduced laser stimulus. Pain ratings were assessed before, during and after treatment. Using electroencephalography (EEG) we measured anticipatory neural responses and pain-evoked potentials to laser heat to determine how expectation of analgesia affected the response to a placebo manipulation. This was a reproducibility study and as such the experimental procedure was repeated after a minimum gap of 2 weeks. Significant reductions in pain-evoked potentials were shown after treatment. The anticipatory responses did not change after treatment for the control and sham-treatment groups in the first session but were significantly lower in the repeat session relative to the first session in the sham-treatment group only. A significant correlation was found between the reduction in state anxiety in the repeat session relative to the first and the reduction in the anticipatory response in the sham-treatment group. Receiving a placebo treatment appears to cause a lasting change in the cognitive processing of pain for at least 6 weeks. This cognitive change may be facilitated by a change in state anxiety.

Our brains on the internet - smarter, dumber, neither?

As part of my re-entry catching up with accumulated articles, I want to point out some contrasting takes on how gadgets, the internet, our modern pace, multi-tasking and attention span, etc. are influencing our brains:
Richtel describes a number of experiments demonstrating how multitasking can diminish the ability to focus on or switch between tasks

While many people say multitasking makes them more productive, research shows otherwise. Heavy multitaskers actually have more trouble focusing and shutting out irrelevant information...and they experience more stress...even after the multitasking ends, fractured thinking and lack of focus persist.

Jonah Lehrer reviews "The Shallows," a new book by Nicholas Carr on the internet and the brain. Carr takes a dire view of what the internet is doing to our brains, but Lehrer counters:

There is little doubt that the Internet is changing our brain. Everything changes our brain. What Carr neglects to mention, however, is that the preponderance of scientific evidence suggests that the Internet and related technologies are actually good for the mind. For instance, a comprehensive 2009 review of studies published on the cognitive effects of video games found that gaming led to significant improvements in performance on various cognitive tasks,...Carr's argument also breaks down when it comes to idle Web surfing. A 2009 study by neuroscientists at the University of California, Los Angeles, found that performing Google searches led to increased activity in the dorsolateral prefrontal cortex, at least when compared with reading a "book-like text." Interestingly, this brain area underlies the precise talents, like selective attention and deliberate analysis, that Carr says have vanished in the age of the Internet. Google, in other words, isn't making us stupid -- it's exercising the very mental muscles that make us smarter.

Pinker offers a sanguine and sane assessment:

New forms of media have always caused moral panics...such panics often fail basic reality checks...If electronic media were hazardous to intelligence, the quality of science would be plummeting. Yet discoveries are multiplying like fruit flies, and progress is dizzying. Other activities in the life of the mind, like philosophy, history and cultural criticism, are likewise flourishing.

...the effects of experience are highly specific to the experiences themselves. If you train people to do one thing (recognize shapes, solve math puzzles, find hidden words), they get better at doing that thing, but almost nothing else. Music doesn’t make you better at math, conjugating Latin doesn’t make you more logical, brain-training games don’t make you smarter...The effects of consuming electronic media are also likely to be far more limited than the panic implies. Media critics write as if the brain takes on the qualities of whatever it consumes, the informational equivalent of “you are what you eat.” As with primitive peoples who believe that eating fierce animals will make them fierce, they assume that watching quick cuts in rock videos turns your mental life into quick cuts or that reading bullet points and Twitter postings turns your thoughts into bullet points and Twitter postings.

...to encourage intellectual depth, don’t rail at PowerPoint or Google. It’s not as if habits of deep reflection, thorough research and rigorous reasoning ever came naturally to people. They must be acquired in special institutions, which we call universities, and maintained with constant upkeep, which we call analysis, criticism and debate. They are not granted by propping a heavy encyclopedia on your lap, nor are they taken away by efficient access to information on the Internet.

The new media have caught on for a reason. Knowledge is increasing exponentially; human brainpower and waking hours are not. Fortunately, the Internet and information technologies are helping us manage, search and retrieve our collective intellectual output at different scales, from Twitter and previews to e-books and online encyclopedias. Far from making us stupid, these technologies are the only things that will keep us smart.

Believing is seeing.

Langer et al. do experiments showing that vision can be improved by manipulating our mind-set:

.... In Study 1, participants were primed with the mind-set that pilots have excellent vision. Vision improved for participants who experientially became pilots (by flying a realistic flight simulator) compared with control participants (who performed the same task in an ostensibly broken flight simulator). Participants in an eye-exercise condition (primed with the mind-set that improvement occurs with practice) and a motivation condition (primed with the mind-set “try and you will succeed”) demonstrated visual improvement relative to the control group. In Study 2, participants were primed with the mind-set that athletes have better vision than nonathletes. Controlling for arousal, doing jumping jacks resulted in greater visual acuity than skipping (perceived to be a less athletic activity than jumping jacks). Study 3 took advantage of the mind-set primed by the traditional eye chart: Because letters get progressively smaller on successive lines, people expect that they will be able to read the first few lines only. When participants viewed a reversed chart and a shifted chart, they were able to see letters they could not see before. Thus, mind-set manipulation can counteract physiological limits imposed on vision.

MindBlog back in Madison - the anterior insula rests from risk alertness

I'm finally back in my University of Wisconsin office, after a month of mainly being on the road, and I'm very much looking forward to settling in to have more time to read and face the  list of accumulated articles that might be the subjects of blog posts.  No matter how comfortable I think I am feeling while traveling, I still am surprised on the return to familiar settings as I watch the body relax to reveal a stored up tiredness, indicating how much energy was being put into the alertness and vigilance - being poised for the unexpected in foreign settings.

It would appear that my being more alert to risks associated with travel was, according to Mohr et al.,  strenuously exercising my anterior insula:

In our everyday life, we often have to make decisions with risky consequences, such as choosing a restaurant for dinner or choosing a form of retirement saving. To date, however, little is known about how the brain processes risk. Recent conceptualizations of risky decision making highlight that it is generally associated with emotions but do not specify how emotions are implicated in risk processing. Moreover, little is known about risk processing in non-choice situations and how potential losses influence risk processing. Here we used quantitative meta-analyses of functional magnetic resonance imaging experiments on risk processing in the brain to investigate (1) how risk processing is influenced by emotions, (2) how it differs between choice and non-choice situations, and (3) how it changes when losses are possible. By showing that, over a range of experiments and paradigms, risk is consistently represented in the anterior insula, a brain region known to process aversive emotions such as anxiety, disappointment, or regret, we provide evidence that risk processing is influenced by emotions. Furthermore, our results show risk-related activity in the dorsolateral prefrontal cortex and the parietal cortex in choice situations but not in situations in which no choice is involved or a choice has already been made. The anterior insula was predominantly active in the presence of potential losses, indicating that potential losses modulate risk processing.