Speed-accuracy modulation in case of conflict: the roles of activation and inhibition

Abstract

This study investigated how the speed-accuracy balance is modulated by changes in the time course of motor activation and inhibition of a primed response. Responses and event-related brain potentials were recorded in a paradigm in which the first stimulus indicated the correct response with 80% validity. The remaining 20% of the trials required no response (no-go) or a response opposite to the cued hand (change trials). Subjects were instructed either to balance speed and accuracy or to emphasize speed at the cost of accuracy. Analyses of error patterns, reaction time distributions and brain potentials show that subjects can modulate the amount of activation of the primed response. More surprisingly, the engagement of inhibition of the response also varied with the speed-accuracy instruction. The results are consistent with a model where the frontothalamic loop actively controls both the activation and the inhibition of responses, depending on the current task requirements.

Event-rate effects in the flanker task: ERPs and task performance in children with and without AD/HD

“…Together these results suggest that the N2 is an index of the processing of conflicting response information, a theory that is supported by evidence of the N2 in other conflict-related paradigms such as the Stroop task (Liotti et al, 2000;West and Alain, 2000) and stop-signal task (Band et al, 2003).…”

How to withhold or replace a prepotent response: An analysis of the underlying control processes and their temporal dynamics

“…This led them to conclude that a fast but non-selective inhibition mechanism is involved in the stop-signal task (consequently, responses could be suppressed at late, peripheral stages), whereas a slower but more selective mechanism is involved in the stop-change task (consequently, responses would be suppressed at central stages). Subsequent studies using different stop-change paradigms were not able to replicate de Jong et al's LRP results (Band et al, 2003;Krämer, Knight, & Münte, 2011). Nevertheless, Krämer et al (2011) still argued that different inhibitory mechanisms were involved in both tasks because they observed a fronto-central N2 component on stop-signal trials but not on stop-change trials.…”

“…'X') appears. In the cued variant of the go/nogo task (Band, Ridderinkhof, van der Molen, 2003;Bekker, Kenemans & Verbaten, 2004;Bruin, Wijers, & van Staveren, 2001;Jonkman, Lansbergen & Stauder, 2003;Randall & Smith, 2011;Smith, Jonstone & Barry, 2006), a cue provides information about which response is probably required and subjects are asked to prepare this response (a key press with a left finger, a right finger, or no response). Whether or not the cued response is subsequently required is clarified by a second stimulus that follows after a variable delay.…”

“…Some studies compared trials on which subjects had to cancel a planned go response (go/nogo) with trials on which they had to replace it (go/change) (e.g. Band et al, 2003;Randall & Smith, 2011). Band et al observed an N2 in both conditions (although there were some subtle differences), and proposed that similar inhibitory mechanisms might be involved.…”

“…In this period, subjects should have prepared the go1 response, but they do not know yet whether a go1 cue or a stop/change signal will appear. We included amplitudes of all trials except those on which the go1 response was given too late (those trials were also excluded from subsequent ERP analyses), and submitted them to a one-tailed t-test assessing whether they are different from zero (see Band et al, 2003 for a similar assessment of motor preparation in the response-priming paradigm).…”