Monday, April 14, 2008
The journal Nature Neuroscience latest edition focuses on the Nature of Decision-Making. The studies are quite interesting and do raise many questions about how our brain works. Here is the brief overview of the journal's articles,
The ability to make appropriate choices is critical for survival. Successful decision making requires the integration of sensory information, motivational states and potential outcomes to select the best action. Recently, there has been great progress in our understanding of the neural mechanisms supporting decision making in a wide range of contexts, including risky choices and social interactions. This special focus on decision making contains four reviews that highlight recent achievements in this important field.
Using sophisticated brain imaging techniques, the researchers found that they can predict people's simple decisions up to 10 seconds before they're conscious of making such a choice. "It seems that your brain starts to trigger your decision before you make up your mind," said the study's lead author, John-Dylan Haynes of the Max Planck Institute for Human Cognitive and Brain Sciences in Germany. "We can't rule out free will, but I think it's very implausible. The question is, can we still decide against the decision our brain has made?" The study is the latest salvo in a longstanding scientific and philosophical debate over whether what we perceive as "free will" decisions are actually made before we're aware that we're making them. . . .
In this experiment, however, Haynes and his colleagues found that two regions of the brain responsible for even higher-order decision-making - the frontopolar cortex and the parietal cortex - were activated even earlier when people were asked to press a button with either their right or left hands. Employing both functional magnetic resonance imaging and pattern recognition statistical techniques, the researchers were able to predict which button people would choose before they made their conscious decisions - as much as 10 seconds early, "an eternity," Haynes said. Haynes believes that delay suggests the absence of free will as most people define it. . . .
Tufts University philosopher Daniel Dennett, on the other hand, offers a different way of thinking about the results of Haynes's experiment: "If you take a deep breath and think about it more, the making of the decisions themselves takes time. The noticing of the decision takes time," Dennett said. "That doesn't mean that we don't have free will."
Decision neuroscience, as this field of study is called, has potential applications in medicine, economics, marketing, consumer behavior, even criminal justice. In the future, research in the field could help people with neurological motor disorders such as Parkinson's disease. It also could identify people whose decision-making abilities are impaired through injury or from birth, leading to poor judgment or even criminal behavior. "We're getting closer and closer to understanding how the brain works and how the mind works," Dennett said. "We obviously can't help these conditions until we do."