tDCS application for the inhibitory control. A pilot study with Event-Related Potential

Objective The present study investigates a new neurocognitive intervention aimed at rehabilitating two altered cognitive skills, inhibition and attention, in clinical populations such as addictions and alcoholic patients. Participants and methods Healthy participants (N=59; 18-31 years) were all randomly assigned to four different conditions: Group 1 (G1; n=15) was our control condition; G2 (n=17) was the placebo group; G3 (n=17) was performing a cognitive training on inhibition; G4 (n=10) was receiving the transcranial Direct Current Stimulation (tDCS) to neuromodulate the right Inferior Frontal Cortex (rIFC) four times in a week (20 minutes each session; 2mA) while performing the same cognitive training on inhibition. As pre-test (T1), post-test (T2) and follow-up (T3) all participants performed a Go/No-go task and a face detection task while an Event-Related Potential (ERPs) recording (32 channels) was conducted. Results An increase in the correct detections and a decrease in the reaction time on the Go/No-go task was registered at T2 for all groups and this effect was maintained at T3. Whereas, the rate of commission errors was similar between T1, T2 and T3 in all groups. At the neurophysiological level, instead, there is a significant difference in the latency of the N2d component, reflecting the conflict monitoring. Indeed, N2d was earlier both for G3 and G4 compared to G1 and G2. This was true at T2 compared to T1 and persisted in T3. Moreover, we found a marginal difference in the latency of the P3d component, indexing the inhibition function per se, that was reduced at T2 as compared with T1 for all groups. Conclusion Overall, our preliminary data suggest that the cognitive training specifically impacts neurophysiological processes related to inhibition. Furthermore, the inhibitory skills of healthy people seem to be enhanced by repeated paradigms, such as the Go/No-go task.