Mental representations of movements. Brain potentials associated with imagination of eye movements

Abstract

Objective: Current research in motor imagery is focused on similarities between actual and imagined movements on a central and a peripheral level of the nervous system. The present study measured slow cortical potentials (DC-potentials) during execution and internal simulation of memorized saccadic eye movements.

Methods: In 19 healthy righthanded subjects DC-potentials were recorded from 28 electrodes during execution and during imagination of a sequence of memorized eye movements during a visual imagery condition.

Results: Both oculomotor conditions showed a similar global level and similar topography of performance related DC-potentials, both strongly differed from the visual imagery condition and were lateralized to the left hemisphere.

Conclusion: This study therefore supports the hypothesis that cortical brain structures responsible for execution and imagination of memorized saccadic eye movements are similar. The observed left hemispheric lateralization is in contrast to a previous study using bimanual movements. This discrepancy is discussed in relation to recent observations in apractic patients with parietal lesions.