Representation of response alternatives in human presupplementary motor area: multi-voxel pattern analysis in a go/no-go task.

A debate exists as to the role of the presupplementary motor area (preSMA) in cognitive control. Recent findings suggest that preSMA plays a central role in conflict resolution and encodes response alternatives as opposed to simply the presence of conflict. Evidence of neuronal heterogeneity within preSMA of non-human primates suggests that univariate analysis of functional MRI data may not provide adequate resolution to fully characterize cognitive control-related responses. Here, multi-voxel pattern analysis (MVPA) is employed to examine the distributed patterns of activity in preSMA associated with both successful go responses and no-go inhibitions. In a go/no-go task, univariate analysis showed undifferentiated activation of preSMA in response to both go and no-go stimuli. However, when an anatomically-defined preSMA ROI was subjected to MVPA, a significant difference in the activation pattern encoded by go as compared to no-go stimuli was observed. These differences in preSMA activation are consistent with the ongoing maintenance and manipulation of stimulus-action representations.