Correlations between hand preference and cortical thickness in the secondary somatosensory (SII) cortex of the common marmoset, Callithrix jacchus

Behav Neurosci. 2008 Dec;122(6):1343-51. doi: 10.1037/a0013279.

Abstract

Cortical asymmetries are well established in humans for language and motor regions and correlate with handedness. Here the authors investigate structural differences in the hemispheres of left- and right-handed common marmosets using surface photography and histology. The hand preferences of 11 marmosets were assessed over their adult life span using a simple reaching task. A significant correlation was found between the length of the right lateral sulcus/brain weight and the % right-hand preference (r = .86, p = .001). Cortical thickness on the superior bank of the right lateral sulcus posteriorly was also positively correlated with % right-hand preference (r = .69, p = .025). Comparison of this site with previously published functional maps of the marmoset cortex show this area corresponds to SII, a region involved in tactile processing and somatosensory discriminations. It is suggested that the correlation between SII thickness and right-hand preference would be consistent with the fact that right-handed marmosets are more proactive than left-handers in exploring novel objects by touch. Enlargement of a cortical area involved tactile discriminations could be a precursor to the evolution of right-handedness as a population bias.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Brain Mapping
  • Callithrix / anatomy & histology*
  • Callithrix / physiology*
  • Evoked Potentials, Somatosensory / physiology*
  • Functional Laterality
  • Neural Pathways
  • Psychomotor Performance / physiology*
  • Somatosensory Cortex / anatomy & histology*
  • Upper Extremity*