Forskning

August 10, 2011

Expectation of having consumed caffeine can improve performance and mood

L Dawkins et al, Expectation of having consumed caffeine can improve performance and mood, Appetite, 2011, Article in Press.

These authors explored whether caffeine, and expectation of having consumed caffeine, affects attention, reward responsivity and mood using double-blinded methodology. 88 participants were randomly allocated to ‘drink type’, either caffeinated or decaffeinated coffee, and ‘expectancy’ manipulations. Both caffeine and expectation of having consumed caffeine improved attention and psychomotor speed. Expectation enhanced self-reported vigour and reward responsivity. Self-reported depression increased at post drink for all participants, but less in those receiving or expecting caffeine. These results suggest caffeine expectation can affect mood and performance but do not support a synergistic effect.