• Human;
  • Sleep;
  • K-complex;
  • ANS


Spontaneous K-complexes during stage 2 sleep were scored on nine subjects to study 1) rate of occurrence and 2) autonomic correlates, specifically the heart rate response, number of finger vasoconstrictions, number of galvanic skin responses, and number of skin potential responses. Records for two nights of sleep were available for five subjects.

Spontaneous K-complexes occur with considerable regularity at a rate of 1.21 per minute with a range over subjects from. 75 to 1.93 per minute. There was no significant change in this rate over six hours of sleep nor was there a significant difference over two nights of sleep.

When compared with control portions of the record, spontaneous K-complexes were significantly associated on both nights one and two with an increase in heart rate, increased frequency of vasoconstrictions, an increase in number of GSRs, and an increase in number of skin potential responses. There were no autonomic changes associated with isolated sleep spindles.