Behavioral and neurophysiological modulation of error-related processes

The term brain modulation refers to a wide range of interventions that allow modifying the central nervous system. The general purpose of this dissertation will regard the investigation and modulation of error-related processes through the use of behavioral interventions and noninvasive brain stimulation (NIBS). In order to accomplish this aim, three studies were conducted. Study 1 investigated the motivation-cognition interaction. In particular, this study aimed to increase error awareness by using rewards in a group of healthy older adults, compared to younger adults. Results showed a reduction of error awareness when participants were rewarded, both older and younger adults. This detrimental effect of rewards suggests more attention in planning motivational interventions with the aim to modulate error awareness. Study 2 aimed to investigate the neural bases of error awareness and modulate error awareness by using on-line transcranial magnetic stimulation (TMS). Results revealed an implication of the dorsolateral prefrontal cortex (DLPFC) in error awareness. However, this modulation was specifically induced by a single-pulse TMS paradigm, compared to a paired-pulse TMS paradigm that did not produce a modulation of the process. These results highlight how subtle variations of the TMS paradigm can differently affect error awareness. Study 3 investigated the behavioral and neurophysiological modulation of error-related processes induced by a low-frequency repetitive TMS paradigm. Results showed a reduction of the error positivity (Pe), an electrophysiological component associated with error awareness, only when the left DLPFC was stimulated, compared to the homologous right DLPFC and the Vertex. This result contributes to provide new knowledge about error-related processes, in particular about the neural bases of the Pe. Finally, a critical review of these studies will provide general insights for the design of future modulatory interventions.