Date of this Version

January 2004

Document Type

Journal Article

Publication Details

Lyvers, M., Brooks, J., & Matica, D. (2004). Effects of caffeine on cognitive and autonomic measures in heavy and light caffeine users. Australian Journal of Psychology, 56 (1), 33-41.
This is an electronic version of an article published in The Australian Journal of Psychology

Abstract

Caffeine effects on arousal and cognition were assessed in relation to habitual caffeine intake. After drinking either decaffeinated coffee or decaffeinated coffee plus 300 mg caffeine, 22 heavy caffeine consumers (HCCs) and 26 light caffeine consumers (LCCs) were examined on various cognitive, autonomic, and anxiety measures. In LCCs only, caffeine significantly improved performance of the Wisconsin Card Sorting Test, and significantly increased state anxiety scores. Caffeine significantly increased spontaneous skin conductance responses in HCCs and LCCs alike. The HCCs and LCCs did not differ on measures of trait anxiety or neuroticism. Results are discussed in terms of the cognitive enhancing and nonspecific arousing effects of caffeine in relation to caffeine tolerance.