Merck

Caffeine as an attention enhancer: reviewing existing assumptions.

Psychopharmacology (2012-12-18)
Suzanne J L Einöther, Timo Giesbrecht
ABSTRACT

Despite the large number of studies on the behavioural effects of caffeine, an unequivocal conclusion had not been reached. In this review, we seek to disentangle a number of questions. Whereas there is a general consensus that caffeine can improve performance on simple tasks, it is not clear whether complex tasks are also affected, or if caffeine affects performance of the three attention networks (alerting, orienting and executive control). Other questions being raised in this review are whether effects are more pronounced for higher levels of caffeine, are influenced by habitual caffeine use and whether there effects are due to withdrawal reversal. Literature review of double-blind placebo controlled studies that assessed acute effects of caffeine on attention tasks in healthy adult volunteers. Caffeine improves performance on simple and complex attention tasks, and affects the alerting, and executive control networks. Furthermore, there is inconclusive evidence on dose-related performance effects of caffeine, or the influence of habitual caffeine consumption on the performance effects of caffeine. Finally, caffeine's effects cannot be attributed to withdrawal reversal. Evidence shows that caffeine has clear beneficial effects on attention, and that the effects are even more widespread than previously assumed.

MATERIALS
Product Number
Brand
Product Description

Supelco
Melting point standard 235-237°C, analytical standard
Supelco
Caffeine solution, analytical standard, 1.0 mg/mL in methanol
Caffeine for system suitability, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Caffeine, Sigma Reference Standard, vial of 250 mg
Sigma-Aldrich
Caffeine, meets USP testing specifications, anhydrous
Sigma-Aldrich
Caffeine, powder, ReagentPlus®
Sigma-Aldrich
Caffeine, BioXtra
Supelco
Caffeine Melting Point Standard, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Caffeine, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Caffeine, anhydrous, 99%, FCC, FG
Supelco
Mettler-Toledo Calibration substance ME 18872, Caffeine, analytical standard, for the calibration of the thermosystem 900, traceable to primary standards (LGC)
Sigma-Aldrich
Caffeine, anhydrous, tested according to Ph. Eur.
Caffeine, European Pharmacopoeia (EP) Reference Standard
Supelco
Caffeine, certified reference material, TraceCERT®
USP
Caffeine melting point standard, United States Pharmacopeia (USP) Reference Standard
USP
Caffeine, United States Pharmacopeia (USP) Reference Standard