Masked affective stimuli moderate task difficulty effects on effort-related cardiovascular response

This experiment investigated the combined effect of masked affective stimuli and task difficulty on effort-related cardiovascular response. Cardiovascular reactivity (ICG, blood pressure) was recorded during a baseline period and performance of an easy or difficult attention task in which participants were exposed to masked sad vs. happy facial expressions. As expected, participants in the sad-faces/easy and happy-faces/difficult conditions showed stronger sympathetic nervous system discharge to the heart and vasculature--shorter preejection period, higher systolic blood pressure--indicating more effort than participants in the sad-faces/difficult and happy-faces/easy conditions. Total peripheral resistance reacted similarly as preejection period and systolic blood pressure. The findings are compatible with the effects of consciously experienced affect on effort-related cardiovascular response.