Electrodermal activity during total sleep deprivation and its relationship with other activation and performance measures

Disturbances in the sleep–wake rhythm and/or sleep deprivation are frequent events in modern life. Many subjects can be chronically sleep deprived as a result of current life style expectations as occurs in the case of night shift workers, on-call doctors, truck drivers and airplane pilots, situations of prolonged athletic competition, insomnia or sleep apnea (Bonnet and Arand 1995). Such deteriorations in activation are frequently the cause of industrial or automobile accidents found in some sectors, and are simply added to the list of ‘human errors’ (Kuhn 2001; Philip et al. 1999). Total sleep deprivation (TSD) has been shown to negatively impact a wide range of cognitive, behavioural, physiological, and emotional measures (Dinges 1992; Horne 1988, 1992; Pilcher and Huffcutt 1996). One of the most prominent and consistent effects of sleep loss is deterioration in vigilance and activation which has been reported in a wide variety of objective and subjective measures. The basal level of electrodermal activity (EDA) is an accepted vigilance index used in diverse psychophysiological fields (Freixa i Baqué 1990). It is quite surprising that this measure has been ignored in previous sleep deprivation studies. During normal wakefulness, as a subject relaxes and nears a presomnolence state, his/her skin resistance level (SRL) progressively increases. In this situation an inverse relation between the vigilance level and the SRL is found (Freixa i Baqué 1990). The circadian variations in body temperature have been reported to positively correlate with skin conductance levels (SCL) and to negatively correlate with SRL (BuelaCasal 1990). In studies carried out during sleep, it has been found that different EDA recording procedures do not provide compatible information. Throughout the slow sleep phases an increase in SCL recordings is found until it reaches a maximum Correspondence: Elena Miró Morales, PhD, Facultad de Psicologı́a, Universidad de Granada, Campus Universitario de la Cartuja s/n., CP. 18071, Granada, Spain. Tel.: 34-958-244275; fax: 34-958-243749; e-mail: [email protected] J. Sleep Res. (2002) 11, 105–112