Background: Depending on baseline catecholamine levels and executive cognitive function, caffeine may enhance or disturb such functions. Trait anxiety and stress are associated with increased...Show moreBackground: Depending on baseline catecholamine levels and executive cognitive function, caffeine may enhance or disturb such functions. Trait anxiety and stress are associated with increased catecholamine action and cognitive effects of caffeine as a function of these factors is largely unknown. Hypotheses: First, high trait performance anxiety increases state performance anxiety after a stressor. Second, caffeine leads to a higher increase in state performance anxiety, also moderated by trait anxiety. Third, caffeine leads to a worse WM performance, also depending on trait anxiety. Fourth, after the consumption of caffeine, high TBR will enhance WM, whereas low TBR will impair it. Methods: A continuous performance task (N-back) was used to assess WM and the interference by negative stimuli. A stress procedure was used to induce performance anxiety and electroencephalogram was used to calculate TBR. To assess trait anxiety and state performance anxiety, the Cognitive Test Anxiety Scale (CTAS) and the State Performance Anxiety Scale (SPAS) were used. Results: TBR moderated the effect of caffeine on WM. High TBR corresponded to an enhancement of WM, whereas caffeine may have overruled the effect of TBR on WM. CTAS moderated increases in SPAS after a stressor, but not when in interaction with caffeine manipulation. CTAS, in interaction with caffeine manipulation, did not influence WM. Conclusions: Our first and fourth hypotheses were confirmed, as the association between high CTAS and a higher increase in SPAS after a stressor, and the moderation role of TBR towards WM, alone and partially when in interaction with the caffeine manipulation, were confirmed. Our second and third hypotheses were rejected, as CTAS, in interaction with caffeine manipulation, did not influence WM or the increase in SPAS after a stressor.Show less
