SLEEP-DEPRIVATION AFFECTS SPEECH

Historical accounts of sleep loss studies have described changes in th e content and patterns of speech, although to date these claims have n ot been systematically studied. We examined the effects of sleep loss on the spontaneous generation of words during a verbal word fluency ta sk and the articulation of speech during a vocalized reading task. Nin e subjects underwent two counterbalanced 36-hour trials involving slee p deprivation (SD) and no sleep deprivation (NSD). After SD, there was a significant deterioration in word generation and a tendency for sub jects to become fixated within a semantic category. There was a signif icant reduction in the subjects' use of appropriate intonation in the voice after SD, with subjects displaying more monotonic or flattened v oices. These findings are discussed in light of neuropsychological evi dence concerning the functions of sleep in relation to the frontal cor tex and in light of the implications for interpersonal communication i n the event of sleep loss.