H. Babkoff et al., Trial-to-trial variance in choice reaction time as a measure of the effectof stimulants during sleep deprivation, MIL PSYCHOL, 13(1), 2001, pp. 1-16
Performance stability, as assessed by trial-to-trial variance in a choice r
eaction time (RT) task, was evaluated as a measure of stimulant effects on
performance during sleep deprivation. Administration of methylphenidate, pe
moline, and a placebo began 16 hr into a 64-hr sleep-deprivation protocol.
Performance stability deteriorated significantly, especially during the cir
cadian nadirs. In absolute terms, sleep deprivation increased trial-to-tria
l variance more than it increased the mean correct RT. In addition, this me
asure demonstrated differing effects of the 2 drug regimens. Pemoline, at a
dose of 37.5 mg every 12 hr, significantly reduced the overall average eff
ects of sleep loss on performance stability during the first 24 hr of drug
administration. Pemoline also reduced circadian-related instability in perf
ormance throughout the study. Methylphenidate, at a dose of 10 mg every 6 h
r, counteracted circadian-related instability in performance during the fir
st 24-hr period of drug administration (16-40 hr of sleep deprivation) but
not during the second 24-hr period (40-64 hr of sleep deprivation). Methylp
henidate did not significantly affect the overall average effects of sleep
loss on performance stability. Thus, trial-to-trial variance appears to be
a valuable measure for elucidating stimulant effects during sleep deprivati
on.