Effects of 24 and 36 Hours of Sleep Deprivation on Visual Dependency

Abstract: Objective: Sleep deprivation may alter sensory integration. The research question was whether 24 and 36 h of sleep deprivation affect visual dependency (the weighting of visual information for vertical perception). Method: Twenty healthy participants ( M age 25.3 years) were tested after a normal night of sleep and at 24 and 36 h of sleep deprivation. Participants sat in a dark room and rotated an illuminated projected rod to their perceived vertical without visual references (subjective visual vertical) and with a clockwise or counterclockwise frame (visual dependency). Subjective scores of sleepiness were taken. Results: Visual dependency was elevated at 24 h of sleep deprivation compared to the control for counterclockwise frame tilts ( p = .001). Subjective sleepiness increased from 0.4 in the control to 5.4 at 24 h of sleep deprivation and 6.7 at 36 h of sleep deprivation ( p < .001 vs. control). Discussion: There was an increase in visual dependency in the rod and frame test at 24 h of sleep deprivation but not at 36 h. This study suggests sensory reweighting to compensate for a night of sleep deprivation.