Caffeine, cognitive function, and mood:
Caffeine, mood, reaction time, attention, and memory: The ingestion of 250 mg caffeine, by 17 caffeine consumers (mean intake 375mg caffeine per day), after 30 hours of abstinence, had a greater effect than placebo on mood and choice reaction time. Caffeine also improved selective attention and memory in both those who had abstained from caffeine and those who had maintained their habitual intake levels, suggesting no evidence of withdrawal on these markers of mental performance. (13)
Caffeine, attention, cognitive function, mood, and performance:
Expectations of caffeine consumption on attention, reward response and mood were tested in 88 participants who were randomly assigned to caffeinated coffee, decaffeinated coffee or placebo. In both groups attention and cognitive/physical function speed increased. Alertness and reward responsiveness were improved in the placebo group. In all participants, self-reported depression increased, but less in the caffeine coffee group than the decaffeinated coffee group. (14)