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

The present study analyses the variations of the skin resistance level (SRL) during 48 h of total sleep deprivation (TSD) and its relationship to body temperature, self-informed sleepiness in the Stanford Sleepiness Scale (SSS), and reaction time (RT). All of the variables were evaluated every 2 h except for the SSS, which was evaluated every hour. A total of 30 healthy subjects (15 men and 15 women) from 18 to 24 years old participated in the experiment. Analyses of variance (ANOVAs) with TSD days and time-of-day as factors showed a substantial increase of SRL, SSS, and RT, and a decrease in body temperature marked by strong circadian oscillations. The interaction between day by time-of-day was only significant for RT. Furthermore, Pearson's correlations showed that the increase of SRL is associated to the decrease in temperature (mean r=-0.511), the increase of SSS (mean r=0.509), and the deterioration of RT (mean r=0.425). The results support previous TSD reports and demonstrate the sensitivity of SRL to TSD. The non-invasive character of SRL, its simplicity, and its relationships with other activation parameters, widely validated by previous literature, convert SRL into an interesting and useful measure in this field.