Woman uses brain implant to stimulate her brain’s pleasure center, study reports

io9.com reports:

The 1986 case of a woman addicted to stimulating herself with a brain implant is chronicled in a scientific article from Pain journal called Compulsive thalamic self-stimulation: a case with metabolic, electrophysiologic and behavioral correlates.

The unnamed woman had been suffering from chronic pain… and had tried a number of drugs to deal with it. Though she was an alcoholic, doctors prescribed opium-based painkillers to her and she had been known to take more than her recommended dose. With her history of drug addiction, it’s easy to see why doctors would have imagined that a brain implant would be the best course of action for the treatment of her chronic pain. Little did they know that the woman would become addicted to that, too…

Is dopamine the neural basis for motivation?

The NY Times reports:

People talk of getting their “dopamine rush” from chocolate, music, the stock market, the BlackBerry buzz on the thigh — anything that imparts a small, pleasurable thrill. Familiar agents of vice like cocaine, methamphetamine, alcohol and nicotine are known to stimulate the brain’s dopamine circuits, as do increasingly popular stimulants like Adderall and Ritalin.

In the communal imagination, dopamine is about rewards, and feeling good, and wanting to feel good again, and if you don’t watch out, you’ll be hooked, a slave to the pleasure lines cruising through your brain. Hey, why do you think they call it dopamine?

Yet as new research on dopamine-deficient mice and other studies reveal, the image of dopamine as our little Bacchus in the brain is misleading…

In the emerging view, discussed in part at the Society for Neuroscience meeting last week in Chicago, dopamine is less about pleasure and reward than about drive and motivation, about figuring out what you have to do to survive and then doing it. “When you can’t breathe, and you’re gasping for air, would you call that pleasurable?” said Nora D. Volkow, a dopamine researcher and director of the National Institute on Drug Abuse. “Or when you’re so hungry that you eat something disgusting, is that pleasurable?”

New field of ‘optogenetics’ offers new insights into brain function

Wired reports on the new field of optogentics. This research takes light-sensitive plant cells and implants them in animals, allowing light to activate specific neurons in a way not previously possible.

Internet use can “boost” brain function

Science Daily reports:

UCLA scientists… found that middle-aged and older adults with little Internet experience were able to trigger key centers in the brain that control decision-making and complex reasoning after just one week of surfing the Web.

The findings, presented Oct. 19 at the 2009 meeting of the Society for Neuroscience, suggest that Internet training can stimulate neural activation patterns and could potentially enhance brain function and cognition in older adults.

The “new science of learning”

The journal Science has published a paper on a developing “new science of learning.” The article’s abstract states:

Human learning is distinguished by the range and complexity of skills that can be learned and the degree of abstraction that can be achieved compared with those of other species. Homo sapiens is also the only species that has developed formal ways to enhance learning: teachers, schools, and curricula. Human infants have an intense interest in people and their behavior and possess powerful implicit learning mechanisms that are affected by social interaction. Neuroscientists are beginning to understand the brain mechanisms underlying learning and how shared brain systems for perception and action support social learning. Machine learning algorithms are being developed that allow robots and computers to learn autonomously. New insights from many different fields are converging to create a new science of learning that may transform educational practices.

The article is available here (subscription required). Science Daily has a summary of the article here.

Note: this is cross-posted with my Education Blog.

New study suggests we learn more from successes than from failures

Science Daily reports:

If you’ve ever felt doomed to repeat your mistakes, researchers at MIT’s Picower Institute for Learning and Memory may have explained why: Brain cells may only learn from experience when we do something right and not when we fail.

In the July 30 issue of the journal Neuron, Earl K. Miller, the Picower Professor of Neuroscience, and MIT colleagues Mark Histed and Anitha Pasupathy have created for the first time a unique snapshot of the learning process that shows how single cells change their responses in real time as a result of information about what is the right action and what is the wrong one.

“We have shown that brain cells keep track of whether recent behaviors were successful or not,” Miller said. Furthermore, when a behavior was successful, cells became more finely tuned to what the animal was learning. After a failure, there was little or no change in the brain — nor was there any improvement in behavior.

New drug restores memories lost by Alzheimer’s patients

Science Daily reports:

A drug similar to one used in clinical trials for treatment of rheumatoid arthritis and psoriasis has been found to rescue memory in mice exhibiting Alzheimer’s symptoms.The discovery by UC Irvine scientists offers hope that a new treatment may be on the horizon for people in the early stages of Alzheimer’s, the leading cause of elderly dementia afflicting more than 5 million people in the U.S. and for which no cure exists.

This finding seems to support the notion that memory is ‘hard wired’ into our brains but some kind of executive function is necessary to retrieve memory…

The validity of evolutionary psychology

NEWSWEEK takes a critical look at evolutionary psychology:

Founded in the late 1980s in the ashes of sociobiology, [evolutionary psychology] asserts that behaviors that conferred a fitness advantage during the era when modern humans were evolving are the result of hundreds of genetically based cognitive “modules” preprogrammed in the brain. Since they are genetic, these modules and the behaviors they encode are heritable—passed down to future generations—and, together, constitute a universal human nature that describes how people think, feel and act, from the nightclubs of Manhattan to the farms of the Amish, from the huts of New Guinea aborigines to the madrassas of Karachi… We in the 21st century, asserts evo psych, are operating with Stone Age minds.

Over the years these arguments have attracted legions of critics who thought the science was weak and the message (what philosopher David Buller of Northern Illinois University called “a get-out-of-jail-free card” for heinous behavior) pernicious.

Right ear more responsive to requests than left ear, study finds

Wired reports:

You’re in a loud and sweaty Italian dance club when a woman approaches you. To be heard over the techno, she leans in close and yells into your ear, “Hai una sigaretta?”

If she spoke into your right ear, you would be twice as likely to give her a cigarette than if she asked by your left ear, according to a new study that employed this methodology in the clubs of Pescara, Italy. Of 88 clubbers who were approached on the right, 34 let the researcher bum a smoke, compared with 17 of 88 whom she approached on the left.

“The present work is one of the few studies demonstrating the natural expression of hemispheric asymmetries, showing their effect in everyday human behavior,” write psychologists Daniele Marzoli and Luca Tommasi of the University G. d’Annunzio in Italy in the journal Naturwissenschaften.

It’s the latest in a series of studies that show that sound from both human ears is processed differently within the brain. Researchers have noted that humans tend to have a preference for listening to verbal input with their right ears and that given stimulus in both ears, they’ll privilege the syllables that went into the right ear. Brain scientists hypothesize that the right ear auditory stream receives precedence in the left hemisphere of the brain, where the bulk of linguistic processing is carried out.

Brain perceives happiness more quickly than it perceives fear, study finds

Science Daily reports:

…An international group of experts has carried out an in-depth study into how we process emotional expressions, looking at the pattern of cerebral asymmetry in the perception of positive and negative facial signals…

The results, published in the latest issue of the journal Laterality, show that the right hemisphere performs better in processing emotions. “However, this advantage appears to be more evident when it comes to processing happy and surprised faces than sad or frightened ones”, [study co-author J. Antonio Aznar-Casanova] points out.

“Positive expressions, or expressions of approach, are perceived more quickly and more precisely than negative, or withdrawal, ones. So happiness and surprise are processed faster than sadness and fear”, explains Aznar-Casanova.

This research study adds to previous ones, which had revealed asymmetries in the way the brain processes emotions, and enriches the international debate in cognitive-emotional neuroscience in terms of how to define the exact way in which human beings process these facial expressions.