OSARI, an Open-Source Anticipated Response Inhibition Task

Action initiation and action inhibition follow the same time course when compared under matched experimental conditions

The ability to initiate an action quickly when needed and the ability to cancel an impending action are both fundamental to action control. It is often presumed that they are qualitatively distinct processes, yet they have largely been studied in isolation and little is known about how they relate to one another. Comparing previous experimental results shows a similar time course for response initiation and response inhibition. However, the exact time course varies widely depending on experimental conditions, including the frequency of different trial types and the urgency to respond. For example, in the stop-signal task, where both action initiation and action inhibition are involved and could be compared, action inhibition is typically found to be much faster. However, this apparent difference is likely due to there being much greater urgency to inhibit an action than to initiate one in order to avoid failing at the task. This asymmetry in the urgency between action initiation and action inhibition makes it impossible to compare their relative time courses in a single task. Here, we demonstrate that when action initiation and action inhibition are measured separately under conditions that are matched as closely as possible, their speeds are not distinguishable and are positively correlated across participants. Our results raise the possibility that action initiation and action inhibition may not necessarily be qualitatively distinct processes but may instead reflect complementary outcomes of a single decision process determining whether or not to act.NEW & NOTEWORTHY The time courses of initiating an action and canceling an action have largely been studied in isolation, and little is known about their relationship. Here, we show that when measured under comparable conditions the speeds of action initiation and action inhibition are the same. This finding raises the possibility that these two functions may be more closely related than previously assumed, with potentially important implications for their underlying neural basis.

The effect of staircase stopping accuracy and testing environment on stop-signal reaction time

The stop-signal task is widely used in experimental psychology and cognitive neuroscience research, as well as neuropsychological and clinical practice for assessing response inhibition. The task requires participants to make speeded responses on a majority of trials, but to inhibit responses when a stop signal appears after the imperative cue. The stop-signal delay after the onset of the imperative cue determines how difficult it is to cancel an initiated action. The delay is typically staircased to maintain a 50% stopping accuracy for an estimation of stopping speed to be calculated. However, the validity of this estimation is compromised when participants engage in strategic slowing, motivated by a desire to avoid stopping failures. We hypothesized that maintaining stopping accuracy at 66.67% reduces this bias, and that slowing may also be impacted by the level of experimenter supervision. We found that compared with 50%, using a 66.67% stopping accuracy staircase produced slower stop-signal reaction time estimations (≈7 ms), but resulted in fewer strategic slowing exclusions. Additionally, both staircase procedures had similar within-experiment test-retest reliability. We also found that while individual and group testing in a laboratory setting produced similar estimations of stopping speed, participants tested online produced slower estimates. Our findings indicate that maintaining stopping accuracy at 66.67% is a reliable method for estimating stopping speed and can have benefits over the standard 50% staircase procedure. Further, our results show that care should be taken when comparing between experiments using different staircases or conducted in different testing environments.

Comparing anticipatory and stop-signal response inhibition with a novel, open-source selective stopping toolbox

Response inhibition is essential for terminating inappropriate actions and, in some cases, may be required selectively. Selective stopping can be investigated with multicomponent anticipatory or stop-signal response inhibition paradigms. Here we provide a freely available open-source Selective Stopping Toolbox (SeleST) to investigate selective stopping using either anticipatory or stop-signal task variants. This study aimed to evaluate selective stopping between the anticipatory and stop-signal variants using SeleST and provide guidance to researchers for future use. Forty healthy human participants performed bimanual anticipatory response inhibition and stop-signal tasks in SeleST. Responses were more variable and slowed to a greater extent during the stop-signal than in the anticipatory paradigm. However, the stop-signal paradigm better conformed to the assumption of the independent race model of response inhibition. The expected response delay during selective stop trials was present in both variants. These findings indicate that selective stopping can successfully be investigated with either anticipatory or stop-signal paradigms in SeleST. We propose that the anticipatory paradigm should be used when strict control of response times is desired, while the stop-signal paradigm should be used when it is desired to estimate stop-signal reaction time with the independent race model. Importantly, the dual functionality of SeleST allows researchers flexibility in paradigm selection when investigating selective stopping.

Impairments in Emotion Recognition and Positive Emotion Regulation Predict Social Difficulties in Adolescent With ADHD

BACKGROUND

Emotional dysregulation, poor emotion recognition and impaired response inhibition have been highlighted as potential contributors to social difficulties in adolescents with attention-deficit/hyperactivity disorder (ADHD). It is currently unknown how these areas of impairment relate to one another; therefore, this study aims to identify the areas of emotion regulation which are associated with social difficulties in adolescents with ADHD, and determine whether emotion regulation mediates the relationship between deficits in response inhibition and emotion recognition, and social functioning, in this cohort.

METHODS

Thirty Australian adolescents (Male = 21) with ADHD completed measures of response inhibition, emotion recognition, and emotion regulation.

RESULTS

Positive emotion regulation was significantly associated with social difficulties. Although emotion recognition significantly predicted social difficulties, there was no relationship between emotion recognition and emotion regulation in this sample, ruling out emotion regulation as a mediator of emotion recognition and social difficulties. Whilst response inhibition was significantly correlated with positive emotion regulation, positive emotion regulation did not mediate the relationship between response inhibition and social difficulties.

CONCLUSIONS

Difficulties recognising and regulating emotions appear to independently contribute to social difficulties in adolescents with ADHD. Interventions to increase emotional understanding and developing strategies to down-regulate positive emotions may be beneficial.

Exploring stop signal reaction time over two sessions of the anticipatory response inhibition task

Various behavioural tasks measure response inhibition encompassing the ability to cancel unwanted actions, evaluated via stop signal reaction time (SSRT). It is unclear whether SSRT is an unchangeable inherent measure of inhibitory network integrity or whether it can improve with repetition. The current study explored if and how SSRT changed over two sessions for the Anticipatory Response Inhibition Task (ARIT), and how this compared with the Stop Signal Task (SST). Forty-four participants repeated the ARIT and SST over two sessions. SSRT and its constituent measures (Go trial reaction time, stop signal delay) were calculated. SSRT reflecting non-selective response inhibition was consistent between sessions in the ARIT and SST (both p > 0.293). Reaction time and stop signal delay also remained stable across sessions in the ARIT (all p > 0.063), whereas in the SST, reaction time (p = 0.013) and stop signal delay (p = 0.009) increased. SSRT reflecting behaviourally selective stopping on the ARIT improved (p < 0.001) over two sessions, which was underpinned by changes to reaction time (p < 0.001) and stop signal delay (p < 0.001). Overall, the maximal efficiency of non-selective inhibition remained stable across two sessions in the ARIT. Results of the SST confirmed that non-selective inhibition can, however, be affected by more than inhibitory network integrity. Behaviourally selective stopping on the ARIT changed across sessions, suggesting the sequential neural process captured by the SSRT occurred more quickly in session two. These findings have implications for future studies that necessitate behavioural measures over multiple sessions.