10 January 2007
Use The Force, Luke
by Kate Melville
A University College London (UCL) study has found that you are more likely to perform well if you do not think too hard and instead trust your instincts. Appearing in the journal Current Biology, the research shows that instinctive snap decisions are sometimes more reliable than decisions taken using higher-level cognitive processes.
The experiment involved subjects picking the odd symbol (a rotated version) out of over 650 identical symbols presented on a computer screen. Tracking participants' eye movements, the researchers controlled the time allotted to each individual's search for their target. The visual display screen was switched off at various time intervals either before or after the subjects' eyes landed on the target (between 0 and 1.5 seconds). They then had to decide whether the odd one out was on the left or the right-hand side of the screen.
Intriguingly, the researchers found that participants scored better if they were given no scrutinizing time at all. With only a tiny fraction of a second for scrutinizing the target, subjects performed with 95 percent accuracy. With over a second to scrutinize the image, subjects were only 70 percent accurate. Accuracy was recovered if scrutinizing was allowed to run for more than 4 seconds.
"This finding seems counter-intuitive. You would expect people to make more accurate decisions when given the time to look properly. Instead they performed better when given almost no time to think. The conscious or top-level function of the brain, when active, vetoes our initial subconscious decision - even when it is correct - leaving us unaware or distrustful of our instincts and at an immediate disadvantage. Falling back on our inbuilt, involuntary subconscious processes for certain tasks is actually more effective than using our higher-level cognitive functions," explained Dr Li Zhaoping, of the UCL Department of Psychology.
The researchers say the instinctive decisions were more likely to be correct because the subconscious brain recognizes a rotated version of the same object as different from the original, whereas the conscious brain sees the two objects as identical. For the conscious brain, an apple is still an apple whether rotated or not. So while the lower-level cognitive process spots the rotated image as the odd one out, the higher-level functions override that decision and dismiss the rotated object because it is the same as all the other symbols. When subjects were given the time to engage their higher-level functions, their decisions were therefore more likely to be wrong.
"If our higher-level and lower-level cognitive processes are leading us to the same conclusions, there is no issue. Often though, our instincts and higher-level functions are in conflict and in this case our instincts are often silenced by our reasoning conscious mind. Participants would have improved their performance if they had been able to switch off their higher-level cognition by, for example, acting quickly," explained Dr Zhaoping. "Our eye movements are often involuntary. What seems like a random darting of the eye is often an essential subconscious scanning technique that allows us to pick out unique and distinctive features in a crowd - such as color or orientation. Soon after our eyes have fixed on a target, the conscious or top-down part of cognition engages and examines whether the candidate really is the target or not. If the target is not distinctive enough in the 'eyes' of the conscious, failure of identification can occur."
Source: University College London