Specific forms of neural activity associated with tactile space awareness

Neuroreport. 2002 Jun 12;13(8):997-1001. doi: 10.1097/00001756-200206120-00002.

Abstract

Left tactile extinction, in which a left tactile stimulus fails to access consciousness only when a right stimulus is presented simultaneously, offers a model for studying tactile awareness from its transitory absence. Pairs of transcranial magnetic stimuli (TMS) on the parietal cortex inhibit contralateral tactile perception when separated by an interval of 1 ms. We have applied this technique on the left parietal cortex of right brain damaged (RBD) patients and normal subjects and have shown a selective lack of paired TMS inhibitory effects on right tactile perception of patients during bimanual stimulation. TMS effects were normal during unimanual right stimulation. These results suggest the presence of a specific pattern of inhibitory/excitatory interactions in parietal brain areas as critical for tactile awareness.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Attention / physiology
  • Brain Injuries / pathology
  • Brain Injuries / physiopathology*
  • Electric Stimulation
  • Evoked Potentials, Somatosensory / physiology
  • Extinction, Psychological / physiology
  • Female
  • Functional Laterality / physiology
  • Humans
  • Hypesthesia / pathology
  • Hypesthesia / physiopathology*
  • Magnetics
  • Male
  • Middle Aged
  • Neural Inhibition / physiology
  • Parietal Lobe / injuries
  • Parietal Lobe / pathology
  • Parietal Lobe / physiopathology*
  • Perceptual Disorders / pathology
  • Perceptual Disorders / physiopathology*
  • Physical Stimulation
  • Psychomotor Performance / physiology
  • Reaction Time / physiology
  • Space Perception / physiology*
  • Synaptic Transmission / physiology
  • Touch / physiology*