Intense rapid eye movements during active sleep: an index of neurobehavioral instability.

Rapid Eye Movement (REM) Storms, intense REM bursts during Active Sleep (or REM Sleep), were investigated as an expression of the neural mechanisms involved in overall control of the sleep and waking states. Twenty normal full-term infants were observed in their homes for a 7-hr period when they were 2, 3, 4, and 5 weeks old. Sleep and waking states, and co-occurring behaviors of the mother, were recorded at 10-sec intervals throughout the observation day. During each 10-sec epoch of Active Sleep a rating was made of the infant's rapid eye movements, as follows: No REM, Light REMs, Moderate REMs, or intense REMs (REM Storms). REM Storm rates were related to a measure of stability in the distribution of the sleep and wake states over weeks, derived separately for time the infant was alone and for time the infant was with its mother. REM Storm rates were negatively correlated with state stability in each of these contexts. The results demonstrated a commonality between the incidence of REM Storms and overall sleep-wake state regulation.