In a study led by Virginia Commonwealth University researchers, it was found that loss of one sensory modality is replaced by the remaining senses. The part of the brain that uses hearing to determine sound location is reorganized in deaf animals to locate visual targets.
These findings propose a new theory for cross-modal plasticity: loss of one sensory modality is substituted by another while maintaining the original function of the brain region.
In a study, the team first examined the region of auditory cortex in hearing adult animals that responded to auditory stimuli and controlled orienting and localization behaviors in response to sounds.
"However, in deaf animals, that same cortical region responded to visual stimuli yet still controlled orienting and localization behaviors, thus preserving the functional role of the region despite the loss of its original sensory inputs," said principal investigator Alex Meredith.
According to Meredith, this research provides insight into brain reorganization following sensory loss, which may help researchers better understand how rehabilitative medicine, such as cochlear implants, may function more effectively in deaf patients.
The study was recently published in the Proceedings of the National Academy of Sciences.