Changes in cognitive asymmetries from waking to REM and NREM sleep.

In previous studies, a right hemisphere superiority was shown during REM sleep with respect to Wake and NREM states for right hemisphere tasks. The question can be raised whether the increasing right hemisphere performance during REM is related to right hemisphere tasks only, or whether it is of more general nature. This hypothesis was tested by giving the lateralized Consonant Recognition Task to 16 subjects during waking and upon awakenings from REM and NREM sleep. Results support the hypothesis that right hemisphere superiority in REM sleep is not restricted to right hemisphere tasks.