Investigating task preparation and task performance as triggers of the backward inhibition effect

Psychological Research (2023) 87:1816–1835 https://doi.org/10.1007/s00426-022-01780-x ORIGINAL ARTICLE Investigating task preparation and task performance as triggers of the backward inhibition effect Laura Joy Prosser1 · Motonori Yamaguchi2 · Rachel Swainson1 Received: 25 May 2022 / Accepted: 9 December 2022 / Published online: 26 December 2022 © The Author(s) 2022 Abstract Backward inhibition is posited to aid task switching by counteracting the tendency to repeat a recent task. Evidence that factors such as cue transparency affect backward inhibition seems to imply that it is generated during task preparation, making its absence following trials on which a prepared task was not performed (nogo trials) surprising. However, the nogo method used in previous studies might have prevented detection of preparation-driven effects. We used a truncated-trial method instead, omitting stages of a trial with no need for a nogo signal. In Experiment 1, an n − 2 repetition cost (suggested to indicate backward inhibition) followed trials truncated after response selection, indicating that response execution is not necessary to trigger backward inhibition. In Experiments 2 and 3, no n − 2 repetition cost was obtained following trials truncated after cue presentation. To ensure some task preparation on cue-only trials, Experiment 4 used a double-registration procedure where participants responded to the task cue and the target on each trial. In contrast to Experiments 2 and 3, a small n − 2 repetition cost followed trials truncated after cue responses, affecting cue responses on the current trial. In addition, the n − 2 repetition cost was increased at cue responses and became evident at target responses when the preceding trial also involved a target response. These results imply that backward inhibition might be generated by processes occurring up to and including a cue response, affecting subsequent cue responses, as well as during task performance itself, affecting subsequent cue and target responses. Introduction The environment that we live in is complex, providing a multitude of options for actions that can be performed. Our goals also shift frequently, such that what is an appropriate action from one moment to the next differs. Mayr and Keele (2000) proposed that there is a cognitive control mechanism that enables us to shift more effectively from one goal to the next. This mechanism, known as backward inhibition, is thought to decrease the amount of competition arising from the previous goal/task by inhibiting it when we try to perform a new task, to prevent the previous task from being performed again by mistake. This article asks when backward inhibition is triggered: is it triggered proactively, * Rachel Swainson 1 School of Psychology, University of Aberdeen, Aberdeen, UK 2 Department of Psychology, University of Essex, Colchester, UK 13 Vol:.(1234567890) in advance of difficulty resulting from shifting goals, or reactively, in response to difficulty resulting from shifting goals? Braver and colleagues proposed two distinct modes of cognitive control (Braver, 2012; Braver et al., 2007) that make up the Dual Mechanisms of Control framework. One mode is reactive control, which involves control being assigned when it is needed, at the point at which interference is detected. The other mode of control is proactive control, which is where attention is assigned prior to the need for it. For cognitive control to be reactive there needs to be conflict that is detected, whereas for proactive control there needs to be a contextual task cue that causes goal activation and goal maintenance. Within a backward inhibition task switching paradigm (as was used in this set of experiments), cognitive control would apply a reactive mechanism to dampen conflict that arises from the sharing of responses between tasks (i.e. using the left and right response button for all three tasks) or the use of trivalent stimuli (i.e. stimuli which allow a response from all three tasks), for example. Within the same paradigm, proactive control would be driven by processing of the task cue which occurs on the screen prior to a target being presented. The task cue indicates which task Psychological Research (2023) 87:1816–1835 participants must perform on the upcoming target and therefore processing of this task cue should cause goal activation (i.e. the selection of a task) and goal maintenance (continued selection of the task), which Braver and colleagues suggested results in proactive control. Mayr and Keele (2000) measured backward inhibition by comparing performance on the final trial of two three-trial sequences, ABA and CBA (where A, B and C refer to different tasks). They found that responses were slower on trial n (the final trial) of the ABA trial sequences relative to the CBA trial sequences; this difference is known as the n − 2 repetition cost. Mayr and Keele suggested that this cost is caused by the inhibition put in place on trial n − 1, to prevent interference from the task completed on trial n − 2, needing to be overcome on ABA sequences but not CBA sequences. In Experiment 3, they removed irrelevant distractors from the target screen, so that only one task could be performed on each trial. Although participants could perform the task correctly without a task cue, the researchers still presented task cues and instructed participants to use them explicitly in one condition, whereas participants were not presented with task cues in the other condition. They found an n − 2 repetition cost in the former condition but not in the latter, indicating that backward inhibition depends on proactive control. We also found similar results (Prosser et al., 2020), supporting the idea that backward inhibition is triggered proactively. Several other studies have provided indirect evidence for backward inhibition being triggered proactively. In studies by Astle et al. (2012) and by Costa and Friedrich (2012), finding backward inhibition with stimuli that afforded a response in only one task led the authors to propose that task cues were the most likely trigger. Several studies reported that less transparent (more arbitrary) cue-task relationships were associated with higher n − 2 repetition costs (Arbuthnott, 2005; Arbuthnott & Woodward, 2002; Gade & Koch, 2014; Houghton et al., 2009); the dependency of the size of backward inhibition on an aspect of the task cues in these studies implies that the cue itself might be the trigger for the application of inhibition. [Also see Kuhns et al., (2007), and Hübner et al., (2003), for evidence of inhibition of the previous task being triggered prior to target processing in a flanker-compatibility-effect design.] If backward inhibition is a form of proactive control, it would be triggered prior to target onset, so it should be evident even when target processing was not required on the preceding trial. However, the studies by Schuch and Koch (2003) an (...truncated)