Spatial frequency and right hemisphere: An electrophysiological investigation

Author(s): Bernard, C., Lannou, J., Jouen, F.

Journal/Book: Brain Cognition. 1998; 36: 525 B St, Ste 1900, San Diego, CA 92101-4495. Academic Press Inc Jnl-Comp Subscriptions. 21-29.

Abstract: The influence of the spatial frequency of visual stimuli on hemispheric asymmetry has been studied with visual evoked potentials (VEP). Nineteen different sinusoidal gratings (19 SF from 1 to 10 cpd) were presented in an ON-OFF mode to five right-handed subjects. The amplitude of the VEPs and the latency of the first positive component (C1) were analyzed. The results show that in the low range of spatial frequencies, the latency and the amplitude of C1 are similar in both hemispheres. At medium to high spatial frequencies, the VEPs on the right hemisphere (RH) present shorter latencies and larger amplitudes than those on the left hemisphere (LH). These results, discussed in relation to the directional differences in the lime of callosal interhemispheric transfer, strengthen the idea that the RH is relatively more sensitive than the LH to the spatial component of the visual stimuli.

Note: Article Rebai M, Univ Rouen, Neurophysiol Sensorielle Lab, 1 Rue Thomas Becket, F-76821 Mont St Aignan, FRANCE

Keyword(s): VISUAL-EVOKED-POTENTIALS; INTERHEMISPHERIC TRANSMISSION; ASYMMETRY; INFORMATION; HANDEDNESS

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