Emotional information prioritizes human behavior. How much emotions influence ongoing behavior critically depends on the extent of executive control functions in a given context. One form of executive control is based on stimulus–stop associations (i.e., habitual inhibition) that rapidly and effortlessly elicits control over the interruption of ongoing behavior. So far, no behavioral accounts have explored the emotional impact on habitual inhibition. We aimed to examine the emotional modulation on habitual inhibition and associated psycho-physiological changes. A go/no-go association task asked participants to learn stimulus–stop and stimulus–response associations during 10-day training to form habitual inhibition (without emotional interference). Probabilistic feedback guided learning with varying probabilities of congruent feedback, generating stronger versus weaker pairings. A reversal test measured habitual inhibition strength counteracted by emotional cues (high-arousal positive and negative stimuli compared with neutral ones). Our training protocol induced stable behavioral and psycho-physiological responses compatible with habitual behavior. At reversal, habitual inhibition was evident as marked by significant speed costs of reversed no-go trials for strongly associated stimuli. Positive and negative emotional cues produced larger impact on habitual inhibition. We report first evidence on a cognitive control mechanism that is vulnerable to emotional stimuli and suggest alternative explanations on how emotions may boost or counteract certain behavioral abnormalities mediated by habitual inhibition.

The SMA is fundamental in planning voluntary movements and execution of some cognitive control operations. Specifically, the SMA has been known to play a dominant role in controlling goal-directed actions as well as those that are highly predicted (i.e., automatic). Yet, the essential contribution of SMA in goal-directed or automatic control of behavior is scarce. Our objective was to test the possible direct role of SMA in automatic and voluntary response inhibition. We separately applied two noninvasive brain stimulation (NIBS) inhibitory techniques over SMA: either continuous theta-burst stimulation using repetitive transcranial magnetic stimulation or transcranial static magnetic field stimulation. Each NIBS technique was performed in a randomized, crossover, sham-controlled design. Before applying NIBS, participants practiced a go/no-go learning task where associations between stimulus and stopping behaviors were created (initiation and inhibition). After applying each NIBS, participants performed a go/no-go task with reversed associations (automatic control) and the stop signal task (voluntary control). Learning associations between stimuli and response initiation/inhibition was achieved by participants and therefore automatized during training. However, no significant differences between real and sham NIBS were found in either automatic (go/no-go learning task) or voluntary inhibition (stop signal task), with Bayesian statistics providing moderate evidence of absence. In conclusion, our results are compatible with a nondirect involvement of SMA in automatic control of behavior. Further studies are needed to prove a noncausal link between prior neuroimaging findings relative to SMA controlling functions and the observed behavior.

Theta burst transcranial magnetic stimulation (TBS) is considered to produce plastic changes in human motor cortex. Here, we examined the inhibitory and excitatory effects of TBS on implicit sequence learning using a probabilistic serial reaction time paradigm. We investigated the involvement of several cortical regions associated with implicit sequence learning by examining probabilistic sequence learning in five age- and IQ-matched groups of healthy participants following continuous inhibitory TBS over primary motor cortex (M1); or the supplementary motor area (SMA) or dorsolateral prefrontal cortex (DLPFC) or following intermittent excitatory TBS of M1; or after sham TBS. Relative to sham TBS, probabilistic sequence learning was abolished by inhibitory TBS over M1, demonstrating that this region is critical for implicit motor sequence learning. Sequence learning was not significantly affected by inhibitory TBS over the SMA, DLPFC or excitatory TBS over M1. These results demonstrate that the M1 mediates implicit sequence learning.