Word recall correlates with sleep cycles in elderly subjects

Morning recall of words presented before sleep was studied in relation to i ntervening night sleep measures in elderly subjects. Night sleep of 30 elde rly subjects aged 61-75 years was recorded. Before sleep, subjects were pre sented with a list of paired non-related words and cued recall was asked im mediately after the morning awakening. Recall positively correlated with av erage duration of NREM/REM cycles, and with the proportion of time spent in cycles (TCT) over total sleep time (TST). No significant correlations were found with other sleep or wake measures. These results suggest the importa nce of sleep structure for sleep-related memory processes in elderly adults .