I believe, therefore I am: Effects of self-control beliefs on behavioral and electrophysiological markers of inhibitory and emotional attention control

In this study, a placebo/nocebo neuro-stimulation procedure was employed to investigate if expectations about self-control can influence self-control exertion. More specifically, we recorded behavioral and electrophysiological responses in an emotional antisaccade task in a between-subjects design, in which one group was led to believe that self-control was enhanced (MSC group) and the other that self-control was weakened (LSC group). This set-up allowed to investigate both response and emotional inhibition, as well as different stages at which control can be exerted during task performance, using Event-Related Potential (ERP) methods. Results showed that the bogus neuro-stimulation indeed installed the expectation of respectively better or worse self-control capacity, as well as the retrospective evaluation at the end of the experiment that the neuro-stimulation changed their self-control in that direction. Participants in the MSC compared to the LSC group showed higher accuracy in trials in which inhibitory control was necessary (antisaccade trials). ERP results showed no effect of the placebo/nocebo manipulation at the level of attention and inhibitory control. In sum, this study showed that high-order cognitive processes are not immune to the influence of expectations induced by a placebo/nocebo procedure, and shows that instructions alone can induce a placebo/nocebo effect in cognitive functioning.