title: Impulsivity and time of day: is rate of change in arousal a function of impulsivity?
abstract: Impulsivity has been interpreted as a stable mediator of rate of change in arousal states. To test this hypothesis, 129 Ss differing in impulsivity were given placebo or caffeine at 9:00 a.m. or 7:30 p.m. Recognition memory was tested for the last 20 items from 2 lists of 24 items and 2 lists of 80 items. Scores from this paradigm reflect sustained attention and are thus sensitive to changes in arousal. A 4-way interaction among impulsivity, time of day, drug, and prior stimuli (p < .05) indicated that for those given placebo, recognition memory for long and late lists was poorer the higher the impulsivity in the morning; this pattern reversed in the evening. Caffeine reduced recognition errors. These results indicate that impulsivity is not a stable predictor of rate of change in arousal states. Instead, susceptibility to attentional lapses is mediated by impulsivity-related phase differences in diurnal arousal rhythms.
authors.affiliation: Department of Psychology, Northwestern University, Evanston, Illinois 60208.
authors.forename: K J
authors.initials: KJ
authors.lastname: Anderson
authors.forename: W
authors.initials: W
authors.lastname: Revelle
mesh_terms: D001143:Arousal / Q000187:drug effects; D001288:Attention; D002110:Caffeine / Q000494:pharmacology; D002940:Circadian Rhythm; D005120:Extraversion, Psychological; D006801:Humans; D007175:Impulsive Behavior / Q000523:psychology*; D016014:Linear Models; D008568:Memory / Q000187:drug effects; D008960:Models, Psychological; D013997:Time Factors
chemical_list: D002110:Caffeine