Ultradian Rhythms of right and left Hemisphere Function

Abstract

Two studies are described that demonstrate ultradian shifts in performance on tests of specialized function associated with the left or right cerebral hemispheres. The first study demonstrated that right-handed males who were tested upon wakening from Rapid Eye Movement sleep performed relatively better on visuospatial skills compared to themselves when tested upon wakening from Non-Rapid Eye Movement sleep. In the second study, subjects were tested continuously for eight hours on a written word production test, a test of point localization, and a test of symbol digit substitution. Each of the tests was performed cyclically but with different periods. The results from both studies suggest that underlying cerebral mechanisms for verbosequential and visuospatial function are neurochemical in nature and not neuroanatomical because of the rapid (ultradian) shifts in performance level.

Key Words:

• ultradian
• hemispheric function
• visuospatial
• verbosequential
• cerebral asymmetry
• REM sleep