Dissociation, hemispheric asymmetry, and dysfunction of hemispheric interaction: a transcranial magnetic stimulation approach

J Neuropsychiatry Clin Neurosci. 2004 Spring;16(2):163-9. doi: 10.1176/jnp.16.2.163.

Abstract

The authors investigated the hypothesis that dissociation may represent a functional dysconnectivity syndrome using a transcranial magnetic stimulation (TMS) approach. Transcranial magnetic stimulation investigations that included motor thresholds and the transcallosal conduction time (TCT) reflecting the interhemispheric transfer were performed in 74 right-handed students. All subjects completed the Dissociative Experience Scale. The high dissociators had a significantly lower left hemispheric excitability than right hemispheric excitability. They also had a significantly shorter TCT from the left to the right hemisphere than did the low dissociators. These results suggest that the neural basis of dissociation may involve a cortical asymmetry with a left hemispheric superiority or, alternatively, a lack of right hemispheric integration.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Chi-Square Distribution
  • Corpus Callosum / physiology
  • Dissociative Disorders / physiopathology*
  • Dissociative Disorders / psychology
  • Electromagnetic Fields*
  • Evoked Potentials, Motor / physiology*
  • Female
  • Functional Laterality / physiology*
  • Humans
  • Male
  • Motor Cortex / physiology*
  • Pyramidal Tracts / physiology
  • Statistics, Nonparametric