by ilene - September 15th, 2010 8:18 pm
But I know plenty of right-handed people who are not balanced. Whatever. – Ilene
INGRAM PUBLISHING / GETTY IMAGES
We used to think that the left brain controlled your thinking and that the right brain controlled your heart. But neuroscientists have learned that it’s a lot more complicated.
In 2007, an influential paper in the journal Behavioral and Brain Functions found that while most of us process emotions through the right hemisphere of the brain, about 35% of people — especially victims of trauma — process their hurt and anger through their left brain, where logic and language sit. That may be because they had worked so hard to explain, logically, why they were suffering. But pushing emotions through the left brain taxed it: these people performed significantly worse on memory tests.
Now a new paper — out in the September issue of The Journal of Nervous and Mental Disease — further complicates the picture with a surprising finding: whether you are right-handed, left-handed or ambidextrous (which the authors call, rather delightfully, “inconsistently handed”) seems to be an important clue in understanding how you use your brain to process emotions.
It’s been known for some time that lefties and the ambidextrous are more prone to negative emotions. The new study shows that they also have a greater imbalance in activity between the left and right brains when they process emotions. Of course, you can’t be sure which comes first: maybe angry people are more out of balance, or maybe the inability to find equilibrium makes you angry. As for the left-handed: maybe they’re more angry because the world is designed for the right-handed majority.
The study also used an interesting method to find that angry people are, literally, hot-headed: the authors of the paper — led by Ruth Propper, a psychology professor at Merrimack College in Massachusetts — measured brain-hemisphere activation with a relatively old method called tympanic membrane temperature, which is essentially how hot it is in your inner ear. If you get angry a lot, your head tends to be warmer.
One problem is that the study was small — just 55 undergraduates participated (they were paid $20 each for having to endure ear-temperature tests and psychological questioning). Also, The Journal of Nervous and Mental Disease, while peer-reviewed, is one of less-respected psychology journals. Still, I like…
by ilene - June 6th, 2010 10:58 pm
This is a good article highlighting how scientific research gets misrepresented in the media, making it important to go to the original source. Moreover, often an experiment measures one thing (a surrogate) but makes conclusions that go well beyond what was actually measured. (E.g. high cholesterol levels being used as a surrogate for heart attack risk.) – Ilene
Fish oil helps schoolchildren to concentrate ran a headline in the Observer. Regular readers will remember the omega-3 fish oil pill issue. The entire British news media has been claiming for several years now that there are trials showing that the pill improves school performance and behaviour in mainstream children, despite the fact that no such trial has ever been published.
There is something very attractive about the idea that solutions to complex problems in education lie in a pill.
This paper showed no difference in performance at all. Since it was a brain imaging study, not a trial, the results of the children’s actual performance in the attention task was only reported in a single paragraph. But these results were clear: "There were no significant group differences in percentage correct, commission errors, discriminability, or reaction time."
So this is all looking pretty wrong. Are we even talking about the same academic paper? I’ve a long-standing campaign to get mainstream media to link to original academic papers when they write about them, at least online, with some limited success on the BBC website. I asked the writer Campbell which academic paper he was referring to, but he declined to answer, and passed me on the Stephen Pritchard, the readers’ editor for the Observer, who answered a couple of days later to say he did not understand why he was being involved. Eventually Campbell confirmed, but through Pritchard, that it was indeed a paper from the April edition of the American Journal of Clinical Nutrition.
Similarly, drug reps and researchers will often announce that their intervention has some kind of effect on some kind of elaborate measure of some kind of surrogate outcome: maybe a molecule in the blood goes up in concentration, or down, in a way that suggests the intervention might be effective.
This is all very well. But it’s not the same as showing that something really does actually work back here in
by ilene - April 2nd, 2010 12:01 pm
Déjà vu, all over again.
by ilene - March 16th, 2010 11:19 am
This is interesting. However, the conclusion that "individuals with antisocial personality disorder may not be unaware of… consequences… but instead that their intense reward-seeking motivation consumes their attention wholly until they have fulfilled their desire for reward" seems overstated, and only a small piece of the psychopath puzzle.
For a different perspective, that of a financial writer, and an even farther-fetched conclusion, read the second article below. The same data can be interpreted to show that a trader taking on excessive risk is "hopped up on dopamine" so they can’t see negative consequences, making them "kind of a psychopath." Take all this with a grain of
salt haloperidol. - Ilene
An overactive dopamine reward system in the brain may help explain why psychopaths pursue rewards without regard for consequences, according to new research published this week in the journal Nature Neuroscience. Previous research has found that individuals who suffer from antisocial personality disorder—often referred to as sociopathology or psychopathology, despite debate over whether these are distinct conditions—lack empathy and fear. Yet this new study, from researchers at Vanderbilt University examines what these individuals may have in excess. According to the study, led by Joshua Buckholtz, a graduate student in psychology at Vanderbilt, individuals with antisocial personality disorder traits show signs of dysfunction in dopamine reward systems—suggesting that, in psychopaths, the drive toward reward can overwhelm all else.
Prior to participating in two different experiments, study subjects completed personality tests to identify presence and severity of psychopathic characteristic—including aggression, lack of empathy, and capacity for manipulation, among other things. Drawing on previous research that has established a strong link between substance abuse and psychopathology, in the first experiment researchers gave participants amphetamine, then used functional Magentic Resonance Imaging (fMRI) brain scans to monitor how dopamine release was affected by the stimulant. In a second experiment, study participants were told that they would be paid for performing a simple task, and researchers conducted brain scans while they completed the tasks.
In both experiments, researchers found that participants who had psychopathic characteristics according to the personality test, were more likely than those without those traits to have greater activity in the nucleus accumbens, the area of the brain associated with dopamine reward processing—whether in response to the chemical stimulant, or the suggestion of monetary reward.
The findings suggest that individuals
by ilene - February 10th, 2010 12:45 am
Fascinating article by Psy-Fi’s Tim. (My yellow highlighting.) – Ilene
Courtesy of Tim at The Psy-Fi Blog
Marriage Made in Heaven – or Hell?
A recent development in economics sees the combining of neurology, psychology and economics in an attempt to reduce economic behaviour to brain function and to predict market behaviour from observable brain patterns. Its aim is to glue together a subject that can’t predict human behaviour from analysis of the brain with a subject that can’t predict human behaviour from analysis of people to a subject that can’t predict human behaviour from analysis of economic data.
Welcome to the Neuroeconomics Revolution.
The Busted Flushes of Psychology and Economics
Psychology spent a large part of the last century stuck in a behaviourist dead-end, carrying out endless experiments on animals in an attempt to explain all human behaviour in terms of externally observable responses to equally observable stimuli: think ringing bells causing salivating dogs or rising markets causing manic investors. The net result of this was that the subject ended up befuddled by mice running the wrong way around mazes and found itself generally regarded as the extreme paramilitary wing of the pigeon fanciers association.
Meanwhile economics, the study of how human financial systems operate, also proceeded on the basis that how humans actually behave was irrelevant and arrived at a set of explanations that defied both logic and the evidence of real markets. Yet even as economics has reluctantly faced up to the need to involve psychology in its models so psychology is beginning to recognise that understanding people requires a more detailed look at the way the brain actually works. Taken together we’re witnessing the creation of a new subject.
Neuroeconomics is nothing more or less than the attempt to relate the now observable functioning of the brain, as provided by neuroscientific techniques, with the various models of economics. Advances in brain scanning techniques permit researchers to subject innocent participants to endless pointless questions while inspecting how their brains grapple with the problems. There is no escape.
As you might imagine, the marketeers of the world have leapt on this idea. Martin Lindstrom relates in Buyology how the inspection of people’s brains reveals what more…
by ilene - November 29th, 2009 12:21 am
Our choices are dramatically influenced by the chemicals circulating through our bodies – so how much free choice do we really have? Is free will just an illusion? - Ilene
By John Cloud, courtesy of TIME
Humans have expended a great deal of intellectual energy over the past few thousand years trying to understand the morality (or amorality) of seeking pleasure. Most of philosophy begins with the question of what defines the (or a) good life. But what if the answer to what makes us happy comes down to how much of a particular chemical is circulating in our brain at any particular moment?
(As with risk taking, romantic love, religousness…. – Ilene)
The neurotransmitter dopamine isn’t quite that powerful, but evidence has been mounting for the past 40 years that its activity is key to helping the brain recognize experiences that cause pleasure. The more dopamine a certain event (having sex or eating ice cream, say) triggers, the more strongly that event gets hard-wired in the brain, and the more intensely your brain drives you to revisit it.
That knowledge also helps the brain figure out how much pleasure it can expect from future experiences and, therefore, influences virtually any decision you make about what you might like or not like: whether you should buy the red shirt or black one, whether you’ll enjoy watching Top Chef over Mad Men, whether you should leave your job or whether you should move in with your boyfriend.
Now a new paper in the journal Current Biology shows for the first time that by tinkering with levels of dopamine in the brain, researchers were be able to influence people’s future decisions in a reliable, predictable way. Led by Tali Sharot and Tamara Shiner of the the Wellcome Trust Center for Neuroimaging at University College London, scientists presented 61 healthy volunteers with 80 different vacation locations, such as Brazil, Thailand and Greece, and asked the volunteers to rate how happy they thought they would be visiting each place. Later, 29 of the participants were given 100 mg of levodopa (or L-DOPA), a drug that increases dopamine in the brain; the other 32 were unwittingly given a sugar pill. Forty minutes later, each participant was given a questionnaire about their emotional state, then a list…
by ilene - July 14th, 2009 10:55 pm
Here’s a fascinating New Scientist article on how your brain works, swinging back and forth between order and chaos, neurons firing away in a blizzard of random activity. – Ilene
By David Robson
HAVE you ever experienced that eerie feeling of a thought popping into your head as if from nowhere, with no clue as to why you had that particular idea at that particular time? You may think that such fleeting thoughts, however random they seem, must be the product of predictable and rational processes. After all, the brain cannot be random, can it? Surely it processes information using ordered, logical operations, like a powerful computer?
Actually, no. In reality, your brain operates on the edge of chaos. Though much of the time it runs in an orderly and stable way, every now and again it suddenly and unpredictably lurches into a blizzard of noise.
Neuroscientists have long suspected as much. Only recently, however, have they come up with proof that brains work this way. Now they are trying to work out why. Some believe that near-chaotic states may be crucial to memory, and could explain why some people are smarter than others.
In technical terms, systems on the edge of chaos are said to be in a state of "self-organised criticality". These systems are right on the boundary between stable, orderly behaviour – such as a swinging pendulum – and the unpredictable world of chaos, as exemplified by turbulence…
Full article here.