October 29, 2010

Blindness Gives Better Perception Of Touch

(Ivanhoe Newswire) -- The brain can process sensory information in a fraction of a second, but in special cases it can be processed quicker.  A recent study from the Journal of Neuroscience found that those who are born blind can process tactile signals quicker than those with unimpaired vision.

Daniel Goldreich, PhD and his research team at McMaster University tested the tactile aptitude of 89 non-blind subjects against 57 vision-impaired subjects by tapping each individual's index fingertip with a probe.  After completing simple tasks such as differentiating between small taps and big taps, the subjects of both groups were tested with a small tap that was immediately followed by a bigger, more prolonged vibration used interfere with, or "mask," the subject's ability to perceive the tap.  The vibration interrupts the brain's neural processing of the tap and typically causes the subject to fail to perceive the tap fully.

The researchers found that both groups responded similarly to the simple tasks, but that the vision-impaired group responded much more strongly to the later tests, despite the sensory interference of the vibration.  Subjects in the blind group required shorter gaps of time between the tap and vibration, meaning that they could perceive the tactile signals quicker.  This small gap of time was found to be about equal to the amount of time a blind subject typically needed to move a finger between individual Braille characters while reading.

"Our findings reveal that one way the brain adapts to the absence of vision is to accelerate the sense of touch," Goldreich was quoted as saying.  "The ability to quickly process non-visual information probably enhances the quality of life of blind individuals who rely to an extraordinary degree on the non-visual senses."

SOURCE: The Journal of Neuroscience, October 2010