The independent effects of sleep deprivation and sleep fragmentation on processing of emotional information

Disrupted sleep through sleep deprivation or sleep fragmentation has previously been shown to impair cognitive processing. Nevertheless, limited studies have examined the impact of disrupted sleep on the processing of emotional information. The current study aimed to use an experimental approach to generate sleep disruption and examine whether SD and SF in otherwise healthy individuals would impair emotional facial processing. Thirty-five healthy individuals participated in three-day/two-night laboratory study which consisted of two consecutive overnight polysomnograms and cognitive testing during the day. The first night was an adaptation night of normal sleep while the second was an experimental night where participants underwent either a night of 1) normal sleep, 2) no sleep (SD) or 3) fragmented sleep (SF). The emotional Go/No-Go task was completed in the morning following each night. Data from 33 participants (14 females, mean age = 24.6 years) were included in the final analysis. Following a night of SD or SF, participants performed significantly poorer with emotional (fearful and happy) targets, while no significant changes occurred after a night of normal sleep. Further, sleep deprived individuals experienced additional impairments with notably poorer performance with neutral targets and slower reaction time for all targets, suggesting an overall slowing of cognitive processing speed. These findings suggest that facial recognition in socio-emotional contexts may be impaired in individuals who experience disrupted sleep.