SIMPLE BRAIN MECHANISMS EXPLAIN ARBITRARY HUMAN VISUAL DECISIONS

Science Daily, November 10, 2008

Mark Twain, a skeptic of the idea of free will, argues in his essay "What Is Man?" that humans do not command their minds or the opinions they form. "You did not form that [opinion]," a speaker identified as "old man" says in the essay. "Your [mental] machinery did it for you—automatically and instantly, without reflection or the need of it."

Twain's views get a boost this week from researchers at Washington University School of Medicine in St. Louis and University of Chieti, Italy. In Nature Neuroscience, scientists report that a simple decision-making task does not involve the frontal lobes, where many of the higher aspects of human cognition, including self-awareness, are thought to originate. Instead, the regions that decide are the same brain regions that receive stimuli relevant to the decision and control the body's response to it.

Other researchers had already demonstrated the same principle in primates. But many still assumed that the more complex human brain would have a more general decision-making module that involved the frontal lobe independently of the neural systems for perception and action.

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http://www.scienced aily.com/ releases/ 2008/11/08110919 3435.htm