Enhanced speech perception capabilities in a blind listener are associated with activation of fusiform gyrus and primary visual cortex

Neurocase. 2009;15(2):163-70. doi: 10.1080/13554790802709054. Epub 2009 Feb 25.

Abstract

Blind individuals may learn to understand ultra-fast synthetic speech at a rate of up to about 25 syllables per second (syl)/s, an accomplishment by far exceeding the maximum performance level of normal-sighted listeners (8-10 syl/s). The present study indicates that this exceptional skill engages distinct regions of the central-visual system. Hemodynamic brain activation during listening to moderately- (8 syl/s) and ultra-fast speech (16 syl/s) was measured in a blind individual and six normal-sighted controls. Moderately-fast speech activated posterior and anterior 'language zones' in all subjects. Regarding ultra-fast tokens, the controls showed exclusive activation of supratemporal regions whereas the blind participant exhibited enhanced left inferior frontal and temporoparietal responses as well as significant hemodynamic activation of left fusiform gyrus (FG) and right primary visual cortex. Since left FG is known to be involved in phonological processing, this structure, presumably, provides the functional link between the central-auditory and -visual systems.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blindness / physiopathology*
  • Cluster Analysis
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Psycholinguistics
  • Speech Perception / physiology*
  • Task Performance and Analysis
  • Temporal Lobe / physiology*
  • Visual Cortex / physiology*
  • Visually Impaired Persons*