Read more: 鈥�Consciousness: The what, why and how鈥�
HUMANS are rather proud of their powers of conscious thought 鈥� and rightly so. But there is one aspect of our cognitive prowess that rarely gets the credit it deserves: a silent thinking partner that whirrs away in the background. Behold the power of the unconscious mind!
Perhaps this was demonstrated most startlingly with an experiment done in the 1980s by Benjamin Libet at the University of California, San Francisco (see diagram). People were told to wait a little while and then press a button, and to note the exact time they decided to act on an ultra-precise clock. They also had electrodes placed on their scalp to measure electrical activity in their brain.
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This set-up revealed that . More recently a similar experiment placed people in an fMRI scanner instead of hooking them up to electrodes. This found stirrings in the brain鈥檚 prefrontal cortex up to 10 seconds before someone became aware of having made a decision ().
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These results are sometimes interpreted as disproving the existence of free will. They could equally well mean that we do have free will, but that it is our unconscious mind that is, in fact, in charge, not the conscious one, Neuroscientist John-Dylan Haynes at the Max Planck Institute in Leipzig, Germany, who led the brain scanning study, warns against jumping to this conclusion. 鈥淚 wouldn鈥檛 interpret these early [brain] signals as an 鈥榰nconscious decision鈥�,鈥� he says. 鈥淚 would think of it more like an unconscious bias of a later decision.鈥�
Unfortunately, it is tricky to analyse mental processes that are outside our conscious awareness. Some researchers have even resorted to using ouija boards to try to communicate with people鈥檚 unconscious. And they have had some success, too.
A more orthodox technique is to use a method called 鈥渕asking鈥�, in which an image is flashed in front of the eyes only to be quickly replaced with another before the first image can consciously register. In this way it has been demonstrated that information shown to the unconscious can spill over into conscious thoughts and decisions. For instance, .
Asking people to choose words from a list might seem a rather artificial test, but such unconscious associations can spill over into life outside the research lab. One study, for instance, showed that if the pen and paper were taken out of a briefcase rather than a rucksack. Afterwards no one was aware of it affecting their behaviour.
Make your mind up time
If these ideas are disconcerting, there may be an upside, points out in the Netherlands. Our ability to unconsciously process information may help us to make decisions.
In one study by Dijksterhuis, for instance, people were asked to . These were: making an instant decision, mulling over all the pros and cons for a few minutes, or thinking about an unrelated problem in order to distract them from consciously thinking about the apartments. People chose the objectively best apartment when they used the distraction method. Dijksterhuis thinks that this is because they were unconsciously mulling over the decision while their consciousness was elsewhere.
Some of these findings have recently been questioned as others have been unable to replicate them. Yet there is certainly growing attention paid to the powers of the unconscious. Dijksterhuis reckons that unconscious deliberation can also explain those 鈥渁-ha!鈥� moments when the answer to a problem seems to come from nowhere, as well as times when a searched-for word comes to mind only after we stop trying. 鈥淔or all sorts of decisions we are never aware of all the myriads of influencing factors,鈥� says Haynes.
This article appeared in print under the headline 鈥淭he silent partner鈥�
