A Study Of The Effect Of 50 Hours Of Total Sleep Deprivation On The Physiological And Psychological Functions In Healthy Young Men

Objective: To study the effect of prolonged sleep deprivation on human physiological and psychological functions, and explore the relationship between the changes in this two type of functions, and study the restorative effect of recovery sleep as a countermeasure against sleep deprivation. Methods: 10 healthy young male volunteers (18-21 years old) were subjected to 50 hours of total sleep deprivation (TSD). Oral temperature, electroencephalogram (EEG) with eye closed, mood and reaction time in three tests (visual searching pattern (VSP) test, visual searching figure (VSF) test and serial addition test (SAT)) were recorded before sleep deprivation, during sleep deprivation (6 hours intervals) and after one night of recovery sleep. EEG samples were Fourier transformed. Absolute power was calculated for six bands. Results: (1) TSD induced a significant linear decrease in oral temperature (P < 0.001). (2) TSD induced a significant linear increase in delta (P < 0.01) and theta (P < 0.001) power and a linear decrease in alpha2 power (P <0.001) at C3 derivation. Alpha2, theta and delta power changed significantly in turn by time. (3) TSD led to deterioration in mood states. The negative mood states such as fatigue-inertia, anxiety, depression and confusion-bewilderment showed a linear increase with accumulating hours of TSD (P < 0.01 - 0.00 1), while the positive mood state of vigor-activity showed a linear decrease (P <0.001). (4) The reaction time of VSP, VSF and SAT prolonged significantly (P < 0.01 - 0.00 1). VSP and SAT showed a positive correlation with TSD (P < 0.00 1). SAT changed the earliest at 32 hours of TSD. The three reaction time curves were different. The higher cognitive load the test demanded, the more obviously the reaction time prolonged. After one night of recovery sleep, all parameters returned to the baseline except fatigue-inertia and vigor-activity (P < 0.05 - 0.01). Oral temperature, EEG power spectra and mood states, reaction time had linear correlations (P < 0.05 - 0.00 1). Psychological parameters changed earlier than physiological parameters, and recovered later. Conclusions: Prolonged total sleep deprivation alters thermal modulation, EEG activity, mood states and reaction time. The changes in the physiological and psychological functions have close relations. One night of recovery sleep can be an effective countermeasure against 50 hours of TSD.