Smooth pursuit and saccadic performance impairment upon awakening after total sleep deprivation

The potential impact of sleep inertia on measures of voluntary oculomotor control have been surprisingly neglected. The present study examined the effects of 40 hours of sleep deprivation ?n saccadic (SAC) and smooth pursuit (SP) performance, attentional/visual search performance (Letter Cancellation Task, LCT) and subjective sleepiness (Sleepiness Visual Analog Scale,.SVAS) recorded Immediately after awakening from sleep. Standard polysomnography of nine normal male subjects Was rec?rded for 3 nights (I adaptation, AD; I baseline, BSL; I recovery, REC); BSL and REC were separated by a penod of 40 h of continuous wakefulness, dunng which subjects were tested every two hours. Within 30 s of each morning awakening, a test battery (SAC, SP, U:;:r,SVAS) was administered to subjects In bed. For data analysis, mean performance obtained during thc day preceding the sleep deprivation night was considered as DIUrnalBasehnc" and compared to performance upon awakenings. 360 As a consequence of sleep deprivation, SWS percentage was doubled during REC. Saccade latency 350 Increased (F3,24=7.01; p=.OOI)and velocity decreased significantly (F3,24=7.33; p=.OOI, sec Figure) j 340 upon awakening from REC as compared to the other three conditions; accuracy was unaffected. As 8 330 regards SP, phase did not show any sl"ep inertia effect, while velocity gain of both rightward and .5 leftward SPeye movements was Significantly lower upon awakening from REC as compared to the :e: 320 other conditions p=.04, and F3,24=5.12; p=.OO7, respectively). Finally, number of hits 'S 310 on LCT upon awakening from REC was significantly lower (F2,14=4.71; p=.03) and subjective Qj 300 sleepiness higher (F3,2 I=3. 17; p=.04) a. compared to DIUrnal Baseline. :> 290 It IS concluded that Some measures of voluntary saccadic and smooth pursuit performance, recorded 2H,O upon from sleep episodes before and after 40 hours of sleep deprivation. arc 5 270 negatively affected by the increased sleep depth during the recovery night. The oculomotor performance worscrung IS limited to the measures of speed, while both SAC accuracy and SP phase are unaffected by trl 260 sleep merna. ThISresult IS.paralleled by a worsening of attcntional/visual search performance and by an 250 increase of subjective ratings of sleepiness upon awakening from the same night. Since saccadic DilltBl3a;dirr Ibrlire Rtn:M:ry velocity has recently been found to negatively correlate with simulator vehicle crash rates (I), it is suggested that the adverse effects of sleep deprivation on sleep inertia magnitude should be avoided by CONDmON personnel who perform critical tasks involving high oculomotor control immediately after awakening. 40 H OF SLEEP DEPRJVATlON IMPAIR SACCADIC SPEED AND PURSUIT GAIN ASSESSED UPON AWAKENING FROM RECOVERY SLEEP.