Two modes of mid-frontal theta suggest a role in conflict and error processing

Mid-frontal theta is well-known to be involved in conflict and error-processing. In paradigms known to evoke response conflict, the temporal sequence of events leading up to conflict or error resolution and theta’s involvement in such scenarios is not well understood. Using single-trial analyses of electrophysiological data from participants performing the Flanker (N = 28) and Simon paradigm (N = 18), we probed the relationship between transient theta activity and the underlying metrics of response conflict. We specifically investigated “partial errors”, in which a small burst of muscle activity in the incorrect response effector occurred, quickly followed by a correction. We found evidence for two modes of theta activity, one of which was strongly related to the partial errors. The temporal distribution of this mode of theta was different in the partial error trials compared to the correct trials with no partial error. Furthermore, we saw that this mode of theta occurred later in trials in which a full error was committed. Our findings point to a possible role of theta in error-correction. This adds to the wider theoretical understanding of mid-frontal theta and the possibility of multiple functional roles of theta in different contexts.