title: Individual differences in diurnal rhythms and multiple activation states: a reply to M. W. Eysenck and Folkard.
abstract: Three issues raised by M. W. Eysenck and Folkard are discussed. These include (a) just what individual difference variable is mediating the time of day and caffeine effects; (b) what the difference is in the diurnal rhythms of low and high impulsives; and (c) whether it is necessary to postulate multiple activation states. Suggestions for future research are then given.
mesh_terms: D001143:Arousal / Q000187:drug effects*; D002110:Caffeine / Q000494:pharmacology*; D002940:Circadian Rhythm; D003071:Cognition / Q000187:drug effects; D005120:Extraversion, Psychological; D006801:Humans; D007175:Impulsive Behavior / Q000523:psychology; D007206:Individuality; D007439:Introversion, Psychological; D012919:Social Behavior
chemical_list: D002110:Caffeine