Monday, April 21, 2008

Intelligence And Rhythmic Accuracy Go Hand In Hand

ScienceDaily (Apr. 21, 2008) — People who score high on intelligence tests are also good at keeping time, new Swedish research shows. The team that carried out the study also suspect that accuracy in timing is important to the brain processes responsible for problem solving and reasoning.
Researchers at the medical university Karolinska Institutet and Umeå University have now demonstrated a correlation between general intelligence and the ability to tap out a simple regular rhythm. They stress that the task subjects performed had nothing to do with any musical rhythmic sense but simply measured the capacity for rhythmic accuracy. Those who scored highest on intelligence tests also had least variation in the regular rhythm they tapped out in the experiment.
"It's interesting as the task didn't involve any kind of problem solving," says Fredrik Ullén at Karolinska Institutet, who led the study with Guy Madison at Umeå University. "Irregularity of timing probably arises at a more fundamental biological level owing to a kind of noise in brain activity."
According to Fredrik Ullén, the results suggest that the rhythmic accuracy in brain activity observable when the person just maintains a steady beat is also important to the problem-solving capacity that is measured with intelligence tests.
"We know that accuracy at millisecond level in neuronal activity is critical to information processing and learning processes," he says.
They also demonstrated a correlation between high intelligence, a good ability to keep time, and a high volume of white matter in the parts of the brain's frontal lobes involved in problem solving, planning and managing time.
"All in all, this suggests that a factor of what we call intelligence has a biological basis in the number of nerve fibres in the prefrontal lobe and the stability of neuronal activity that this provides," says Fredrik Ullén.
Publication: 'Intelligence and variability in a simple timing task share neural substrates in the prefrontal white matter', Fredrik Ullén, Lea Forsman, Örjan Blom, Anke Karabanov and Guy Madison, The Journal of Neuroscience, 16 April 2008.
Adapted from materials provided by Karolinska Institutet.
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Tuesday, April 15, 2008

Decision-making May Be Surprisingly Unconscious Activity

ScienceDaily (Apr. 15, 2008) — Contrary to what most of us would like to believe, decision-making may be a process handled to a large extent by unconscious mental activity. A team of scientists has unraveled how the brain actually unconsciously prepares our decisions. Even several seconds before we consciously make a decision its outcome can be predicted from unconscious activity in the brain.
This is shown in a study by scientists from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, in collaboration with the Charité University Hospital and the Bernstein Center for Computational Neuroscience in Berlin. The researchers from the group of Professor John-Dylan Haynes used a brain scanner to investigate what happens in the human brain just before a decision is made. "Many processes in the brain occur automatically and without involvement of our consciousness. This prevents our mind from being overloaded by simple routine tasks. But when it comes to decisions we tend to assume they are made by our conscious mind. This is questioned by our current findings."
In the study, published in Nature Neuroscience, participants could freely decide if they wanted to press a button with their left or right hand. They were free to make this decision whenever they wanted, but had to remember at which time they felt they had made up their mind. The aim of the experiment was to find out what happens in the brain in the period just before the person felt the decision was made. The researchers found that it was possible to predict from brain signals which option participants would take up to seven seconds before they consciously made their decision. Normally researchers look at what happens when the decision is made, but not at what happens several seconds before. The fact that decisions can be predicted so long before they are made is a astonishing finding.
This unprecedented prediction of a free decision was made possible by sophisticated computer programs that were trained to recognize typical brain activity patterns preceding each of the two choices. Micropatterns of activity in the frontopolar cortex were predictive of the choices even before participants knew which option they were going to choose. The decision could not be predicted perfectly, but prediction was clearly above chance. This suggests that the decision is unconsciously prepared ahead of time but the final decision might still be reversible.
"Most researchers investigate what happens when people have to decide immediately, typically as a rapid response to an event in our environment. Here we were focusing on the more interesting decisions that are made in a more natural, self-paced manner", Haynes explains.
More than 20 years ago the American brain scientist Benjamin Libet found a brain signal, the so-called "readiness-potential" that occurred a fraction of a second before a conscious decision. Libet’s experiments were highly controversial and sparked a huge debate. Many scientists argued that if our decisions are prepared unconsciously by the brain, then our feeling of "free will" must be an illusion. In this view, it is the brain that makes the decision, not a person’s conscious mind. Libet’s experiments were particularly controversial because he found only a brief time delay between brain activity and the conscious decision.
In contrast, Haynes and colleagues now show that brain activity predicts -- even up to 7 seconds ahead of time -- how a person is going to decide. But they also warn that the study does not finally rule out free will: "Our study shows that decisions are unconsciously prepared much longer ahead than previously thought. But we do not know yet where the final decision is made. We need to investigate whether a decision prepared by these brain areas can still be reversed."
Journal reference: Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze & John-Dylan Haynes. Unconscious determinants of free decisions in the human brain. Nature Neuroscience April 13th, 2008.
Adapted from materials provided by Max-Planck-Gesellschaft.
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Monday, April 14, 2008

Keep Boys And Girls Together In The Classroom To Optimize Learning, Research Suggests


ScienceDaily (Apr. 14, 2008) — Boys and girls may learn differently, but American parents should think twice before moving their children to sex-segregated schools. A new Tel Aviv University study has found that girls improve boys’ grades markedly at school.
“Being with more girls is good for everybody,” says Prof. Analia Schlosser, an economist from the Eitan Berglas School of Economics at Tel Aviv University. “We find that both boys and girls do better when there are more girls in the class.” She investigated girls and boys in mixed classrooms in the elementary, middle, and high-school grades of the Israeli school system.
In an unpublished paper, Prof. Schlosser concluded that classes with more than 55 percent of girls resulted in better exam results and less violent outbursts overall. “It appears that this effect is due to the positive influence the girls are adding to the classroom environment,” says Prof. Schlosser. She carried out the study while on a post-doctoral fellowship at Princeton University, and will study the effects of gender in higher education lecture halls next.
This is one of few studies of its kind to use scientific data to address the question of gender effects in school.
The Report Card
Boys with more female peers in their classes show higher enrollment rates in both advanced math and science classes, but overall benefits were found in all grades for both sexes.
Prof. Schlosser found that primary-school classrooms with a female majority showed increased academic success for both boys and girls, along with a notable improvement in subjects like science and math. In the middle schools, girls were found to have better academic achievement in English, languages and math. And in high school, the classrooms which had the best academic achievements overall were consistently those that had a higher proportion of girls enrolled.
An Educated Guess
A higher percentage of girls lowers the amount of classroom disruption and fosters a better relationship between pupils and their teacher, a study of the data suggests. Teachers are less tired in classrooms with more girls, and pupils overall seem to be more satisfied when a high female-to-male ratio persists.
Prof. Schlosser was inspired to the study by a “renewed interest on the effects of classroom gender composition on students’ learning, since a new amendment to America’s Title IX regulations gives communities more flexibility in providing single-sex classes and schools.”
Prof. Schlosser concludes that American educators should reconsider the effects of the new trend of same-sex segregation on different sectors of society. Gains for girls from classroom gender segregation could be offset by the loss of boys.
Adapted from materials provided by Tel Aviv University.

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