Behavioural and neural effects of caffeine on cognition in hormonally cycling females
LE3 .A278 2022
2022
Fisher, Derek Champod, Anne Sophie
Acadia University
Master of Science
Masters
Psychology
The present study examined behavioural and neurophysiological effects of caffeine on cognition across menstrual cycle phases. Sixty healthy females with hormonally-mediated menstrual cycles (i.e. using combination oral contraceptives) between the ages of 18-40 participated in a double-blind, placebo-controlled, randomized study. Participants were tested during their menstrual or combination hormonal contraceptive (HC) active cycle phase. Saliva hormone testing was used to confirm menstrual cycle phase. Participants took a caffeine or placebo pill in counterbalanced order before the completion of a visual search task while EEG was recorded. ANCOVAs were used to examine the effects of menstrual phase and drug on behavioural (RT, accuracy) and neurophysiological (amplitude, latency of ERP waveforms previously elicited in visual search tasks; the N2pc and P300) outcome measures. Spearman’s rho was used to examine correlations between hormone levels and caffeine-induced changes for outcome measures. Behavioural results revealed that caffeine improved accuracy but slowed reaction time to targets in the combination HC active phase only. EEG results showed no phase or drug effects on P300 outcome measures. In the caffeine condition, N2pc amplitudes at the parietal occipital region to distractor arrays were significantly larger compared to the placebo condition; this pattern reversed for target arrays. These results suggest a potential reallocation of attention from target to distractor stimuli during the combination HC active cycle phase to maintain task efficiency. Findings contribute to a better understanding of the neurocognitive mechanisms underlying the effects of caffeine on cognition across menstrual cycle phases, which have implications for hormonal birth control as well as hormone therapies for transgender and post-menopausal women.
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https://scholar.acadiau.ca/islandora/object/theses:3878
