PASADENA, Calif.Our belief as to whether we will likely succeed or fail at a given taskand the consequences of winning or losingdirectly affects the levels of neural effort put forth in movement-planning circuits in the human cortex, according to a new brain-imaging study by neuroscientists at the California Institute of Technology (Caltech).
A paper about the researchled by Richard A. Andersen, the James G. Boswell Professor of Neuroscience at Caltechappears in the August issue of PLoS Biology.
Research in Andersen's laboratory includes work to understand the neural mechanisms of action planning and decision-making. The lab is working toward the development of implanted neural prosthetic devices that would serve as an interface between severely paralyzed individuals' brain signals and artificial limbsallowing their planned actions to control the limbs' movements.
In particular, Andersen's group focuses on a high-level area of the brain called the posterior parietal cortex (PPC), where sensory stimuli are transformed into movement plans.
In the current study, Andersen and his colleagues used a functional magnetic resonance imaging scanner to monitor activity in the PPC and other brain areas in subjects who were asked to perform a complex task. Using a trackball, they had to move a cursor to a number of memorized locations on a computer screen, in a predetermined order.
"The subjects were given 1 second to memorize the sequence, 15 seconds to plan their movements in advance, and then only 10 seconds to finish the task," says Igor Kagan, a senior research fellow in biology in the Andersen lab, and a coauthor of the PLoS Biology paper. "We intentionally made the task hardI couldn't do it myself," he says.
The subjects received monetary compensation for participating in the experiment, with their earnings tied to their performance. The amount of money that would be gained (or lost) varied
|Contact: Kathy Svitil|
California Institute of Technology