Investigation of Motor Inhibition Influence on Working Memory Representations

Motor inhibition is a cognitive control ability that allows humans to rapidly stop an action even after initiation. Previous research has demonstrated that motor inhibition influence can extend beyond the action one is trying to suppress (Wessel & Aron, 2017). For example, stopping an action initiated in the right had will also decrease muscle excitability in task-unrelated leg muscles. This discovery led to a global theory of inhibition, which tries to explain this non-selective nature of the inhibition process. Researchers began studying this inhibitory process with Electroencephalography (EEG) and found that the psychological motor inhibition process was reflected in a neural signature, known as the fronto-central P3 event-related potential, that indexes successful response inhibition (Wessel & Aron, 2015). With a way to index response inhibition, scientists were able to demonstrate P3 activation and decreased muscle excitability in task-unrelated muscles when following surprising events (Dutra et al., 2018), which lead to a reappraisal of the breadth of psychologically relevant events that induce inhibitory effects. Scientists then began to wonder if this global theory of inhibition extended even beyond the motor system itself. Indeed, working memory was also inhibited when the P3 component was activated via surprise (Wessel et al., 2016). In our study, we designed a new way of quantifying this disruption of working memory by inhibitory control systems during a hybrid working memory/go-nogo task. Specifically, we tested working memory precision when participants received a go-trial (no inhibition) or a nogo-trial (inhibition).