Preparing for (valenced) action: The role of differential effort in the orthogonalized go/no-go task

Associating reward to task performance has been shown to benefit scores of cognitive functions. Importantly, this typically entails associating reward to the execution of a response, hence intertwining action-related processes with motivational ones. However, recently, preparatory action requirements (go/no-go) and outcome valence (reward/punishment) were elegantly separated using a cued orthogonalized go/no-go task. Functional magnetic resonance imaging results from this task showed that typical areas of the "reward network," like the dopaminergic midbrain and the striatum, predominantly encode action rather than valence, displaying enhanced activity when preparing for action (go) compared to inaction (no-go). In the current study, we used ERPs to probe for differences in preparatory state related to cognitive effort in this task, which has similarly been linked to reward-network activity. Importantly, the contingent negative variation, which is linked to effortful cognitive preparation processes during cue-target intervals, was clearly observed in go trials but not in no-go trials. Moreover, target-locked ERP results (N1 and P3) suggested that attention to the target was enhanced when an action had to be performed (go trials), and typical inhibition-related ERP components were not observed in no-go trials, suggesting a lack of active response inhibition. Finally, feedback-related P3 results could suggest that correct feedback was valued more in motivated go trials, again implying that more effort was required to correctly perform the task. Together, these results indicate that the anticipation of action compared to inaction simultaneously entails differences in mental effort, highlighting the need for further dissociation of these concepts.