The measurement and characteristics of sleep in older persons.

Measures of the sleep structure, patterns and evaluative responses of 40 males and 40 females between the ages of 50-60 years are presented. Measurement methodology is emphasized. The inability to sustain sleep is clearly indexed by the sleep structure measures. These tendencies are greater in the males. The absolute diminution of slow wave sleep is questioned. Sleep pattern measures show wide inter and intra subject variability with few sex differences. Three fourths of the subjects reported naps in a two week period and men report more frequent but shorter naps. The subjective measures have limited concurrent relations to EEG measures and constitute a complex multifaceted content domain. The overall picture is of a system in change characterized by a wide range of individual differences.