Visual stimuli activate auditory cortex in the deaf

Abstract

Previous brain imaging studies have demonstrated responses to tactile and auditory stimuli in visual cortex of blind subjects, suggesting that removal of one sensory modality leads to neural reorganization of the remaining modalities. To investigate whether similar 'cross-modal' plasticity occurs in human auditory cortex, we used functional magnetic resonance imaging (fMRI) to measure visually evoked activity in auditory areas of both early-deafened and hearing individuals. Here we find that deaf subjects exhibit activation in a region of the right auditory cortex, corresponding to Brodmann's areas 42 and 22, as well as in area 41 (primary auditory cortex), demonstrating that early deafness results in the processing of visual stimuli in auditory cortex.

Dissociating cognitive and sensory neural plasticity in human superior temporal cortex

“…Previous studies have used stimuli with different levels of linguistic content to look at plasticity in deaf individuals 2,3 . However, they have not compared language experiences, typically testing only DS.…”

“…These can arise from physiological or developmental processes, or damage or insult 1 , and can be mediated by cognitive or sensory mechanisms. In congenitally deaf people, neural plasticity has been observed in the superior temporal cortex (STC) 2,3 , a region that is associated with auditory and speech sound processing. Although sensory deprivation triggers the reorganization of the cortex, the origin of the anatomical and functional changes observed in the STC of deaf individuals is not only sensory, but also cognitive, as they cannot acquire language through sound, and visual communication strategies, such as the use of sign language and speechreading, need to be developed.…”

Cross-modal plasticity in cuban visually-impaired child cochlear implant candidates: topography of somatosensory evoked potentials

“…The longer the duration of auditory deprivation, the greater the over-representation of visual stimulation in hearing areas. [2][3][4] Furthermore, it has been shown that in the congenitally blind, visual cortical areas are activated during linguistic processing via touch. [5] This evidence of cortical reorganization is known as cross-modal plasticity (CMP).…”

Perte sensorielle et réorganisation cérébrale

“…De nombreuses études ont démontré qu'une plasticité similaire à celle détectée chez les aveugles existerait également chez les sourds. Il semblerait effectivement que, chez ces personnes, les régions auditives soient mobilisées afin de réaliser des tâches de nature visuelle [19][20][21]. Par ailleurs, le développement de prothè-ses auditives (implants cochléaires) permet aujourd'hui de rétablir l'audition chez les sujets sourds [22].…”