Ricerc@Sapienza

When binary economical rewards are offered along a temporal dimension (e.g., Do you prefer 5€ now or 15€ in 120days?) people may show decision conflicts depending on how sensitive they are to the discounting effect of time. EEG studies have shown that during conflict processing of cognitive representations, a rhythmic oscillatory activity in theta rhythm, named midfrontal theta (MFT), increases over the medial frontal cortex (MFC). MFT may index the temporal dynamics of different brain areas, operating as a synchronizer during the request of control. Despite the correlational link between MFC activation and MFT has been demonstrated, what remains unknown is the extent to which MFT causally reflects cognitive control processing during behavioural performance. The transcranial Alternating Current Stimulation (tACS) is an emerging technique that changes endogenous patterns of oscillatory activity by entraining the neural networks acting on the behavioural performance in a frequency-dependent manner. The present within-subject, sham controlled, cross-over study, aims at exploring the tendency to choose between economic offers in a temporal discounting paradigm during theta, gamma, and sham tACS, with the goal of modulating reaction times (RTs) and choice preferences when different levels of conflict, induced by combining specific delays and payoffs, occur. Hypothesis testing, sample size estimate and analysis of pilot results have been conducted using Bayesian statistics. The study received a priori peer-review (1 Stage) and In-Principle-Acceptance (IPA) as a Registered Report (RR) from the Cortex Journal (https://osf.io/x52vm/) even if data collection has not been already initiated. Importantly, the RR format guarantees publication also in case of null results or mismatch between hypothesis and results. The present proposal aims at securing for the second phase of the study (Stage 2) where data collection and analysis will be finalized.