Dreaming, handedness, and sleep architecture: interhemispheric mechanisms.

Research on individual differences in sleep as a function of handedness is reviewed. Special emphasis is placed on a new way of approaching handedness in terms of degree (strong/consistent versus mixed/inconsistent), as opposed to the traditional focus on direction (right versus left). Handedness differences in sleep architecture reflect increased time in REM sleep and decreased time in NREM sleep in consistent right-handers. A framework relating increased interhemispheric interaction in mixed-handers, increased interhemispheric interaction during episodic retrieval, increased interhemispheric interaction during NREM sleep, and the role of NREM sleep in memory consolidation is discussed.