Hemispheric metacontrol and cerebral dominance in healthy individuals investigated by means of chimeric faces

Brain Res Cogn Brain Res. 2005 Aug;24(3):513-25. doi: 10.1016/j.cogbrainres.2005.03.005. Epub 2005 Apr 7.

Abstract

Cerebral dominance and hemispheric metacontrol were investigated by testing the ability of healthy participants to match chimeric, entire, or half faces presented tachistoscopically. The two hemi-faces compounding chimeric or entire stimuli were presented simultaneously or asynchronously at different exposure times. Participants did not consciously detect chimeric faces for simultaneous presentations lasting up to 40 ms. Interestingly, a 20 ms separation between each half-chimera was sufficient to induce detection of conflicts at a conscious level. Although the presence of chimeric faces was not consciously perceived, performance on chimeric faces was poorer than on entire- and half-faces stimuli, thus indicating an implicit processing of perceptual conflicts. Moreover, the precedence of hemispheric stimulation over-ruled the right hemisphere dominance for face processing, insofar as the hemisphere stimulated last appeared to influence the response. This dynamic reversal of cerebral dominance, however, was not caused by a shift in hemispheric specialization, since the level of performance always reflected the right hemisphere specialization for face recognition. Thus, the dissociation between hemispheric dominance and specialization found in the present study hints at the existence of hemispheric metacontrol in healthy individuals.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Data Interpretation, Statistical
  • Dominance, Cerebral / physiology*
  • Face*
  • Female
  • Fixation, Ocular / physiology
  • Functional Laterality / physiology*
  • Humans
  • Male
  • Photic Stimulation
  • Psychomotor Performance / physiology
  • Reaction Time / physiology
  • Visual Perception / physiology*