Science Tattoos

An amazing gallery of what people will do to themselves (in the name of science?).

The cognitive neuroscience of dyslexia and its repair

John Gabrieli offers a review article in the July 17 issue of Science. Several clips:

Reading is essential in modern societies, but many children have dyslexia, a difficulty in learning to read. Dyslexia often arises from impaired phonological awareness, the auditory analysis of spoken language that relates the sounds of language to print. Behavioral remediation, especially at a young age, is effective for many, but not all, children. Neuroimaging in children with dyslexia has revealed reduced engagement of the left temporo-parietal cortex for phonological processing of print, altered white-matter connectivity, and functional plasticity associated with effective intervention. Behavioral and brain measures identify infants and young children at risk for dyslexia, and preventive intervention is often effective. A combination of evidence-based teaching practices and cognitive neuroscience measures could prevent dyslexia from occurring in the majority of children who would otherwise develop dyslexia.


Brain activation differences in dyslexia and its treatment. Functional magnetic resonance imaging activations shown on the left hemisphere for phonological processing in typically developing readers (left), age-matched dyslexic readers (middle), and the difference before and after remediation in the same dyslexic readers (right). Red circles identify the frontal region, and blue circles identify the temporo-parietal region of the brain. Both regions are hypoactivated in dyslexia and become more activated after remediation.

Brain changes from childhood to young adulthood

Supekar et al. compare large scale brain functional networks in 7-9 and 19-22 year olds and find that they differ significantly in hierarchical organization and interregional connectivity. Subcortical areas are more strongly connected with primary sensory, association, and paralimbic areas in children, whereas young-adults show stronger cortico-cortical connectivity between paralimbic, limbic, and association areas.

National Institutes of Health to be run by a religionist??

Sam Harris doesn't like the idea. Neither do I.

For a mellow start to the week - a Grieg Nocturne

Reason, emotion, and decision-making

Steven Quartz does an opinion piece in Trends in Cognitive Science noting that the tidy separation of our decision making into cognitive and emotional components is not appropriate. Two slightly edited clips:

Many models of judgment and decision-making (JDM) posit distinct cognitive and emotional contributions to decision-making under uncertainty. Cognitive processes typically involve exact computations according to a cost-benefit calculus, whereas emotional processes typically involve approximate, heuristic processes that deliver rapid evaluations without mental effort. However, it remains largely unknown what specific parameters of uncertain decision the brain encodes, the extent to which these parameters correspond to various decision-making frameworks, and their correspondence to emotional and rational processes. A review of basic research suggests that emotional processes encode in a precise quantitative manner the basic parameters of financial decision theory, indicating a reorientation of emotional and cognitive contributions to risky choice.

Despite the popularity and commonsense appeal of distinguishing between cognitive and emotional contributions to JDM, many fundamental issues remain unresolved. Theories can be characterized in terms of the representations and the computations over those representations they posit, and it remains unclear in what ways cognitive and emotional contributions to JDM differ along these dimensions. That is, at the level of representation, what specific parameters of uncertain decision contexts are encoded by the brain, to what extent do such representations correspond to the parameters of various decision-making frameworks, and to what extent do putatively distinct cognitive and emotional contributions to JDM correspond to distinct underlying representations of uncertain decision contexts? Addressing these issues poses several challenges, not least that competing theories are not behaviorally distinguishable. This suggests that adjudicating among different theories requires neural studies that use quantitative and parametric frameworks with suitable resolution to distinguish among the main parameters of these various models and disassociating the representation of their basic parameters from other potential components of uncertain choice, including learning, motivation and salience. Based on recent work using such experimental designs, I suggest that putative distinctions between cognitive and emotional contributions to JDM at the level of representation collapse. Emerging evidence suggests that emotional contributions to JDM do not encode approximate, heuristic evaluations. Rather, it suggests that emotional processes encode the precise, mathematically defined parameters of traditionally cognitive accounts of decision-making from economics and related fields, such as finance. On a more general note, such findings indicate that once-considered basic distinctions, such as that between cognition and emotion, do not map seamlessly onto brain functioning. That is, just as studies of the deep interconnectivity among emotional and cognitive structures suggests that assigning cognitive or emotional specialization to structures is deeply problematic, proposed functional distinctions, such as complexity differences between emotional and cognitive representations and computations, are likewise problematic.

The unconscionable rip-offs of American cell phone companies

Have an iPhone and fume at AT&T? Get furious over listening to Verizon's long introduction before you can leave a message? (They make 850 million a year by forcing us to sit there and wait).. Pogue writes a nice summary of your frustrations. Also, I can't resist passing on this New Yorker cartoon on the iPhone (click on the cartoon to enlarge it).

Training our minds to move matter

We know that our body schema is plastic (see recent post on this), and that our brain's motor routines can learn stable habits of controlling tools and prostheses as if they were our own actual body parts. Ganguly and Carmena have now taken the obvious step of pairing stable recordings from ensembles of primary motor cortex neurons in macaque monkeys with a constant decoder that transforms neural activity to prosthetic movements. Blakeslee points out that this work suggests that learning to move a computer cursor or robotic arm with nothing but thoughts can be no different from learning how to play tennis or ride a bicycle. The brain can form a motor memory to control a disembodied device in a way that mirrors how it controls its own body. Here is their summary, followed by an illustration:

Brain–machine interfaces (BMIs) have the potential to revolutionize the care of neurologically impaired patients. Numerous studies have now shown the feasibility of direct “brain control” of a neuroprosthetic device, yet it remains unclear whether the neural representation for prosthetic control can become consolidated and remain stable over time. This question is especially intriguing given the evidence demonstrating that the neural representation for natural movements can be unstable: BMIs provide a window into the plasticity of cortical circuits in awake-behaving subjects. Here, we show that long-term neuroprosthetic control leads to the formation of a remarkably stable cortical map. Interestingly, this map has the putative attributes of a memory trace, namely, it is stable across time, readily recalled, and resistant to the storage of a second map. The demonstration of such a cortical map for prosthetic control indicates that neuroprosthetic devices could eventually be controlled through the effortless recall of motor memory in a manner that mimics natural skill acquisition and motor control.


Schematics for manual control (MC) and brain control (BC). During MC, the animal physically performs a two-dimensional center-out task using the right upper extremity while the neural activity is recorded. Under BC, the animal performs a similar center-out task using a computer cursor under direct neural control through a decoder trained during MC.

Why I take an omega-3 supplement before bedtime...

I'm into dietary supplements that might be relevant to aging (as in the previous posts on resveratrol), and so thought this study was interesting, along with this summary from Rabin. (By the way, the 'before bedtime' in the title is chosen because we know that significant renewal and turnover of brain nerve cells membranes - whose fluidity is modulated by omega-3 content - occurs during sleep.)

Cortical thickness, MRI, and early Alzheimer's diagnosis

Alongside today's brief post on diet and aging, I thought I would pass on the links to two open access articles in the neurology journal "Brain." The first deals with early diagnosis of Alzheimer's disease using cortical thickness, and the second uses automated MRI measurements to identify individuals with mild cognitive impairment and Alzheimer's disease. (And, I suppose this is a good post in which to act on a request that I provide a link to Caring.com, "a website dedicated to helping people take care of their aging parents and other loved ones.")

Thursday morning Grieg, a Berceuse

I just looked up what a Berceuse is.... it's a lullaby, or soothing composition... This version would have to be considered a fairly robust rendering of the style.

Positive self statements: power for some, peril for others

Wood et al. offer an interesting article in Psychological Science. They present experiments showing that positive self-statements have the potential to make one feel worse if they lie outside one's latitude of acceptance, are self-discrepant and thereby highlight one's failures to meet one's standards, and arouse self-verification motives. Positive self-statements are especially likely to backfire for the very people they are meant to benefit: people with low self-esteem. Such people, by definition, see themselves as failing to meet standards in more domains or in more important domains than do people with high self-esteem. Moreover, self-verification motives should bias people with low self-esteem to reject positive self-statements, but encourage people with high self-esteem to accept them. Here is their abstract:

Positive self-statements are widely believed to boost mood and self-esteem, yet their effectiveness has not been demonstrated. We examined the contrary prediction that positive self-statements can be ineffective or even harmful. A survey study confirmed that people often use positive self-statements and believe them to be effective. Two experiments showed that among participants with low self-esteem, those who repeated a positive self-statement ("I'm a lovable person") or who focused on how that statement was true felt worse than those who did not repeat the statement or who focused on how it was both true and not true. Among participants with high self-esteem, those who repeated the statement or focused on how it was true felt better than those who did not, but to a limited degree. Repeating positive self-statements may benefit certain people, but backfire for the very people who "need" them the most.

Masturbation in the animal kingdom

An interesting piece by Engber from Slate Magazine (The article even includes a link to a YouTube gallery on the subject!):

The recent finding that masturbation improves the quality of human sperm supports the notion that it's an evolved trait and not merely a byproduct of our physiology. According to a branch of evolutionary theory called "sperm competition" that developed in the late-1960s, natural selection can produce just such a change in reproductive behavior. The theory focuses on polyandrous species—i.e., those in which a single female takes multiple partners and the sperm from several potential fathers might end up competing to fertilize the same egg. Under those conditions, the relative quality of male ejaculate very clearly determines whose genes are passed on to the next generation.

So....this is how my cat is manipulating me

If you are a cat person, check out this interesting bit from Gisela Telis (it is open access for the new few weeks). She discusses a new study that reports that our feline friends modify their signature sound when seeking food, adding a higher-frequency element that exploits our sensitivity to infant wails-- thus making it harder to ignore. The article has some sound clips of the effect.

Rapamycin - a midlife longevity drug?

From the Nature 'Editor's Summary' of the paper by Harrison et al.

The antitumour drug rapamycin targets TOR, a kinase that is part of the PI3K–AKT–mTOR cascade, involved in regulating protein translation, cell growth and autophagy. Reducing TOR function is known to extend the life of yeast, worms and flies. Now experiments replicated in three different laboratories demonstrate that rapamycin, fed to male and female mice in a dose that substantially inhibits TOR signalling, can extend their median and maximal lifespan by up to 14%. This life extension was observed in mice fed rapamycin from 270 days of age and also at a late stage in their life, from age 600 days. These findings point to the TOR pathway as a critical point in the control of ageing in mammals and in the pathogenesis of late-life illnesses.

The brain sets fatigue.

Reynolds reviews work showing that fatigue clearly involves more than muscles - the brain also determines how far and hard we can exercise. For example, if the brain's reward center is tricked into thinking more energy is on the way (by swishing a sugar drink in the mouth but not swallowing it, for example), endurance is increased.

To Sleep, Perchance to Analyze

Pogue writes on a neat new sleep monitor that plots and reports back your periods of light sleep, REM sleep, and deep sleep - and then prompts you to note the effects coffee, booze, etc.

Insightful problem solving in birds.

An exchange of letters in PNAS as followup to the subject of the July 3 post on tool use in birds, in which the birds spontaneously use a series of tools to obtain a reward. Lind et al. question whether insight (internal mental modeling of possible problem solutions) or shaping (through successive reinforcement of behaviors) was involved. Authors Bird and Emery respond:

...our study found that rooks not only learned to obtain food by dropping a stone into a tube to collapse a platform, but that they were able to spontaneously choose the correct size and shape tool when presented with subsequent transfer tests and spontaneously solve a completely new task, whereby they had to lift a bucket by using a novel hook tool and manufacture a hook tool from a piece of wire. While we agree that the question of animal “insight” is a complex one in light of studies on chimpanzees and pigeons, we find shaping an unsatisfactory explanation for the spontaneous choice of the correct tool and the bending of the wire. We do not dispute the argument that initial acquisition of stone dropping was brought about through shaping, however, because shaping requires one or more stimulus/behaviour–reward pairings, a novel behaviour such as hook manufacture cannot simply be a case of shaping.

Lost in the internet cloud.

Cautionary sentiments about the idea of moving all of our programs and data from our personal computers to the internet 'cloud.' In the absence of rigid safeguards (which probably won't happen) the erosion of our personal power, autonomy, and privacy will be really scary.

Last week Amazon apparently conveyed a publisher’s change-of-heart to owners of its Kindle e-book reader: some purchasers of Orwell’s “1984” found it removed from their devices, with nothing to show for their purchase other than a refund. (Orwell would be amused.)

Worse, data stored online has less privacy protection both in practice and under the law. A hacker recently guessed the password to the personal e-mail account of a Twitter employee, and was thus able to extract the employee’s Google password. That in turn compromised a trove of Twitter’s corporate documents stored too conveniently in the cloud. Before, the bad guys usually needed to get their hands on people’s computers to see their secrets; in today’s cloud all you need is a password.

Thanks in part to the Patriot Act, the federal government has been able to demand some details of your online activities from service providers — and not to tell you about it. There have been thousands of such requests lodged since the law was passed, and the F.B.I.’s own audits have shown that there can be plenty of overreach — perhaps wholly inadvertent — in requests like these.

Erotica

Pretty mild stuff, by today's standards, but reasonably sensual for Grieg's time - Lyrical Piece Op 43 No 5 - Erotica