Dissociation, hemispheric asymmetry, and dysfunction of hemispheric interaction: a transcranial magnetic stimulation approach.
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.
Spitzer
Carsten
C
Department of Psychiatry and Psychotherapy, Ernst-Moritz-Arndt-University, Greifswald/Stralsund, Germany. spitzer@mail.uni-greifswald.de
Willert
Carsten
C
Grabe
Hans-Joergen
HJ
Rizos
Timolaos
T
Möller
Bertram
B
Freyberger
Harald J
HJ
D000293:Adolescent; D000328:Adult; D016009:Chi-Square Distribution; D003337:Corpus Callosum / Q000502:physiology; D004213:Dissociative Disorders / Q000503:physiopathology* / Q000523:psychology; D004574:Electromagnetic Fields; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D018709:Statistics, Nonparametric