Saturday 10 January 2009

How our brains work as GPS devices to bring things back in perspective
Washington: Very often people forget where they are, but luckily enough, the feeling of being disoriented doesn't last for more than a few seconds-all thanks to the mind. Now, scientists have described how our brain works as a GPS device and tells us the right direction.
The researchers have indicated that animals and young children mainly rely on geometric cues (e.g. lengths, distances, angles) to help them get reoriented.
On the other hand, human adults can also make use of feature cues (e.g. color, texture, landmarks) in their surrounding area.
However, to know which method do we use more often, scientists conducted a set of experiments investigating if human adults have a preference for using geometric or feature cues to become reoriented.
The first experiment, conducted by psychologists Kristin R. Ratliff from the University of Chicago and Nora S. Newcombe from Temple University, was set in either a large or small white, rectangular room with a landmark (a big piece of colourful fabric) hanging on one wall.
Volunteers in the study saw the researcher place a set of keys in a box in one of the corners. All of them were blindfolded and spun around, and were made disoriented. After removing the blindfold, they had to point to the corner where the keys were.
After a break, the volunteers were told the experiment would be repeated, although they wouldn't watch the researcher hide the keys. Without telling the volunteers, the researchers moved the landmark to an adjacent wall during the break.
The change forced the volunteers to use either geometric cues or feature cues, but not both, to reorient themselves and locate the keys.
In the second experiment, the researchers used a similar method, except they switched room sizes (the volunteers moved from a larger room to a smaller room and vice versa) during the break.
According to the results, the brain does not have a distinct preference for certain cues during reorientation.
In the first experiment, volunteers reoriented themselves by using geometric cues in the smaller room but used feature cues in the larger room.
However, the volunteers who went from the larger room to the smaller room in the second experiment also relied on feature cues, searching for the landmark to become reoriented.
During the second experiment, the researchers concluded that the volunteers had a positive experience using feature cues in the large room, so they kept on relying on the landmark in the smaller room to become reoriented.
The results suggested that the brain takes into account a number of factors, including the environment and our past experiences, while determining the best way to reorient us to our surroundings.
The findings were reported in Psychological Science, a journal of the Association for Psychological Science.

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