NEW YORK, March 05 (Reuters) -- Remember this the next time you're in Vegas: scientists now believe hunches may be the brain's "early-warning" system -- and more reliable than commonly thought.
A team of University of Iowa neuroscientists believe they have real evidence of "a complex process of nonconscious signaling" -- in other words, intuition.
The researchers worked with a group of patients who had suffered lesions in the prefrontal cortex of the brain -- located at the front of the brain just over the eyes. Although the patients have normal IQs and no problems functionally, they are emotionally inexpressive and have difficulties making sound decisions -- drifting in and out of jobs and marriages, squandering money, alienating co-workers.
The researchers set up a card game including 6 of those patients and 10 other adults, called the 'normal' subjects. Four decks of cards were placed face down on a table. When turned over, individual cards could supply players with rewards or penalties. However, unbeknownst to those playing, some decks were 'stacked.' Cards drawn from decks 1 and 2 had both higher rewards and penalties than decks 3 and 4. The rewards in decks 3 and 4 were half as great as those in decks 1 and 2, but the penalties were also much smaller. All in all, by consistently choosing cards from decks 3 and 4, a player would gain points over other players.
All of the players were measured for skin conductive response (SCR) throughout the game. SCR measures 'microsweating' -- an involuntary perspiration brought on by emotional responses.
As the game began, cards were drawn evenly from all decks by every player. But the heavy penalty cards in decks 1 and 2 began to show themselves by the 10th card, as did 'microsweating' on the skin of the 'normal' players -- indicating an apprehension regarding those decks.
The researchers began quizzing the players as to whether or not they felt anything unusual about the game. By the 20th card, none of the players had consciously decided the cards were biased, although SCR responses continued to show in the 'normal' players. By card 50, a few normals said they felt decks 1 and 2 were "bad" choices; by card 80, the majority of the 'normals' agreed it was best to stay away from decks 1 and 2.
The brain-damaged players never developed SCR responses throughout the course of the game, and never questioned that decks were 'stacked.' In fact, they continued to choose from the "bad" decks, claiming they felt it was "exciting" to choose from those decks, or that they anticipated the results might change.
Researchers believe the study shows that in normal brains, an emotionally based early-warning system exists, forcing changes in behavior even before intellectual reasoning makes conscious decisions. They speculate the adverse life decisions made by the brain-damaged group may stem from a lack of this intuitive sense.
"These findings are really exciting," Harvard psychologist Dr. Stephen Kosslyn said in the February issue of Science. "Emotion apparently is not something that necessarily clouds reasoning, but rather seems to provide an essential foundation for at least some kinds of reasoning."
Neuroscientists believe the prefrontal cortex is the home of stored emotional 'records' -- and may organize data based on the remembered consequences of past experience. Among other things, "human beings are also the sum of all their previous emotional experiences of rewards and punishments," study co-author Dr. Antonio Damasio told Science.
Behavioral urges drawing on this data may help to form "nonconscious biases (which) guide behavior before conscious knowledge does," the study authors conclude. "Without the help of such biases, overt knowledge may be insufficient to ensure advantageous behavior."
SOURCE: Science (1997;275:1293-1294)
