Effects of caffeine on visual evoked potential (P300) and neuromotor performance.
The stimulant effects of caffeine on cognitive performance have been widely investigated. The visual evoked potential, specially the P300 component, has been used in studies that explain the stimulant mechanisms of caffeine through neurophysiological methods. In this context, the present study aimed to investigate electrophysiological changes (P300 latency) and modification of cognitive and motor performance produced by caffeine. Fifteen healthy volunteers, 9 women and 6 men (26 +/- 5 years, 67 +/- 12.5 kg) were submitted three times to the following procedure: electroencefalographic recording, Word Color Stroop Test, and visual discrimination task. Subjects took a gelatin caffeine capsule (400 mg) or a placebo (P1 and P2), in a randomized, crossover, double-blind design. A one-factor ANOVA and Tukey post hoc test were used to compare dependent variables on the C, P1 and P2 moments. The statistical analyses indicated a non-significant decrease in reaction time, Stroop execution time and latency at Cz on the caffeine moment when compared to the others. Moreover, a non-significant increase in Stroop raw score and latency at Pz could be observed. The only significant result was found at Fz. These findings suggest that the positive tendency of caffeine to improve cognitive performance is probably associated with changes in the frontal cortex, a widely recognized attention area.
Setor de Mapeamento Cerebral e Integração Sensório-Motora, Instituto de Psiquiatria, Universidade Federal do Rio de Janeiro Rio de Janeiro. andreadeslandes@olimpo.com.br
Andréa Camaz
AC
Deslandes
Heloisa
H
Veiga
Maurício
M
Cagy
Roberto
R
Piedade
Fernando
F
Pompeu
Pedro
P
Ribeiro
D000328:Adult; D000704:Analysis of Variance; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000187:drug effects*; D005074:Evoked Potentials, Visual / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects
D000697:Central Nervous System Stimulants; D002110:Caffeine