The temporal dynamic of automatic inhibition of irrelevant actions.

Abstract

Motor inhibition can occur even without conscious perception and any voluntary effort. Although it is now clear that such an inhibitory process needs time to unfold, its exact temporal dynamic remains to be elucidated. Therefore, the present study aims to examine the impact of various temporal factors on automatic motor inhibition using the masked priming task. Results show that this process can be modulated by any factor that introduces time between the mask onset and the execution of target response, whether it stems from a purely external origin (mask-target stimulus-onset asynchrony [SOA]), a purely internal origin (spontaneous reaction time [RT] fluctuations), or a mix of both (RT fluctuations from the target sequence). Moreover, when the external temporal factor could not determine the direction of prime influence, the RT fluctuations had the strongest impact on the priming effect. These RT fluctuations are plausibly the result of spontaneous trial-to-trial changes from more impulsive and error-prone decisions to more cautious and accurate decisions to the target. Indeed, both accuracy and speed were equally required during the task, but both requirements are impossible to achieve perfectly in every trial. This suggests that fluctuations in the level of caution in voluntary decisions can modulate unconscious and involuntary motor inhibition.

A Central Component of the N1 Event-Related Brain Potential Could Index the Early and Automatic Inhibition of the Actions Systematically Activated by Objects

“…The results obtained in yet another tradition of research objectivize the existence of such a systematic inhibition of actions. These results show that selective motor inhibition occurs automatically even without conscious perception and voluntary effort (Eimer and Schlaghecken, 2003; Sumner et al, 2007; Atas and Cleeremans, 2015). They were obtained by using brief presentations of elementary visual objects (primes), which were immediately masked by another visual stimulus before a target appears.…”

A central component of the N1 event-related brain potential could index the early and automatic inhibition of the actions systematically activated by objects

“…The results obtained in yet another tradition of research objectivize the existence of such a systematic inhibition of actions. These results show that selective motor inhibition occurs automatically even without conscious perception and voluntary effort (Eimer & Schlaghecken, 2003;Sumner et al, 2007;Atas & Cleeremans, 2015). They were obtained by using brief presentations of elementary visual objects (primes), which were immediately masked by another visual stimulus before a target appears.…”

“…Without such mechanisms, we could start acting each time a stimulus associated to an action occurs in our environment. This can also be deduced from the duration of the presentation of the primes in the studies mentioned above to show that selective motor inhibition occurs automatically even without conscious perception and voluntary effort (Eimer & Schlaghecken, 2003;Sumner et al, 2007;Vanio et al, 2011;Ocampo and Finkbeiner, 2013;Atas & Cleeremans, 2015). The elementary visual objects used as primes were presented for only 30 to 70 ms before being masked.…”

“…In this type of design, compatible primes delayed reaction times (RTs) to targets. Recent works show that these RT increases reveal an automatic motor inhibition rather than a competition with an incorrect "oppositeto-prime" response (Vanio et al, 2011;Ocampo and Finkbeiner, 2013;Atas & Cleeremans, 2015).…”

“…Given that participants' attention spontaneously fluctuates across the trials of an experiment, it was assumed that both the strength of the systematic activation and the strength of the early automatic inhibition would also fluctuate across trials. In the immediate press task, these fluctuations should lead to faster presses when activation is strong and inhibition weak and to slower presses when activation is weak and inhibition strong (somewhat like in Atas & Cleeremans, 2015). The ERPs elicited by the illumination of the space bar were thus averaged separately according to whether the press was slow or fast.…”