Get Out of Your Own Way: Studies Show the Value of Not Overthinking a Decision
By ROBERT LEE HOTZ. June 27, 2008; Page A9. Wall Street Journal. View original.
Reprinted from The Wall Street Journal:
Fishing in the stream of consciousness, researchers now can detect our intentions and predict our choices before we are aware of them ourselves. The brain, they have found, appears to make up its mind 10 seconds before we become conscious of a decision — an eternity at the speed of thought.
Their findings challenge conventional notions of choice.
“We think our decisions are conscious,” said neuroscientist John-Dylan Haynes at the Bernstein Center for Computational Neuroscience in Berlin, who is pioneering this research. “But these data show that consciousness is just the tip of the iceberg. This doesn’t rule out free will, but it does make it implausible.”
Through a series of intriguing experiments, scientists in Germany, Norway and the U.S. have analyzed the distinctive cerebral activity that foreshadows our choices. They have tracked telltale waves of change through the cells that orchestrate our memory, language, reason and self-awareness.
In ways we are only beginning to understand, the synapses and neurons in the human nervous system work in concert to perceive the world around them, to learn from their perceptions, to remember important experiences, to plan ahead, and to decide and act on incomplete information. In a rudimentary way, they predetermine our choices.
To probe what happens in the brain during the moments before people sense they’ve reached a decision, Dr. Haynes and his colleagues devised a deceptively simple experiment, reported in April in Nature Neuroscience. They monitored the swift neural currents coursing through the brains of student volunteers as they decided, at their own pace and at random, whether to push a button with their left or right hands.
In all, they tested seven men and seven women from 21 to 30 years old. They recorded neural changes associated with thoughts using a functional magnetic resonance imaging machine and analyzed the results with an experimental pattern-recognition computer program.
While inside the brain scanner, the students watched random letters stream across a screen. Whenever they felt the urge, they pressed a button with their right hand or a button with their left hand. Then they marked down the letter that had been on the screen in the instant they had decided to press the button.
Studying the brain behavior leading up to the moment of conscious decision, the researchers identified signals that let them know when the students had decided to move 10 seconds or so before the students knew it themselves. About 70% of the time, the researchers could also predict which button the students would push.
“It’s quite eerie,” said Dr. Haynes.