The role of blind humans' visual cortex in auditory change detection.

Several studies using brain imaging have demonstrated occipital-cortex activation in blind individuals during tactile and auditory tasks, suggesting that the visual cortex deprived of its normal input has adopted a new role in information processing. So far, however, at what stages of information processing and to which perceptual sub-processes this applies remains unclear. We determined the auditory functions of this cortical region in early-blind humans by means of functional magnetic resonance imaging. We found that these areas were not activated by the mere presence of sound, but were involved in the attentive processing of changes in the auditory environment, which is important in detecting potentially dangerous or other important events in the surroundings, for example.