The HED Task Catalog is under development. IDs are not stable until formal release. Comments are welcome at github.com/hed-standard/hed-task/issues.

Stop-Signal Task

HED task ID: hedtsk_stop_signal

Family: Response inhibition and stopping tasks

Also known as: SST, Stop Task, Stop-Signal, Stop Signal

Choice RT task in which an occasional stop signal requires response cancellation; stop-signal reaction time (SSRT) estimates inhibitory latency.

Description

The Stop-Signal Task measures the ability to inhibit a prepotent motor response after it has been initiated. Participants perform a primary go task (button press to go signals) but on a subset of trials, a stop signal (auditory tone or visual cue) appears after a variable delay (stop-signal delay, SSD), instructing them to cancel their response. SSD is adjusted dynamically using a staircase procedure converging on 50% inhibition probability. The key measure is stop-signal reaction time (SSRT), estimated using the race model framework, which indexes the latency of the internal inhibitory process.

Inclusion test

An experiment is an instance of this task when its procedure matches, it manipulates at least one of the listed variables, and it records at least one of the listed measures.

Procedure

On most trials, participants make a speeded response to a go stimulus. On a minority of trials, a stop signal (tone or visual cue) appears after the go stimulus, instructing them to withhold their response.

Manipulation

Stop-signal delay (SSD, adjusted by staircase); proportion of stop trials (typically 25%); go stimulus type.

Measurement

Stop-signal reaction time (SSRT, estimated via race model); go RT; probability of stopping at each SSD.

Variations

Named versions that change what the participant experiences or does. The identifier of a variation is hedvar_<task>__<variation>.

Variation

Description

Justification

Standard SST with Staircase SSD

hedvar_stop_signal__standard_sst_with_staircase_ssd

Dynamic SSD adjustment converging on 50% inhibition probability; yields SSRT via race model.

Canonical adaptive stop-signal delay tracking

Fixed SSD Procedure

hedvar_stop_signal__fixed_ssd_procedure

Predetermined SSDs; simpler but less efficient for SSRT estimation.

Non-adaptive fixed delays; different trial structure

Stop-Change Task

hedvar_stop_signal__stop_change

Stop signal requires switching to alternative response rather than pure inhibition.

Stop signal replaced by change signal; different inhibition-and-substitute

Selective Stop-Signal

hedvar_stop_signal__selective_stop_signal

Stop signal applies to only one of multiple possible responses; probes response-specific inhibition.

Stop signal applies to one response type only; selective inhibition

Proactive vs. Reactive Inhibition Manipulation

hedvar_stop_signal__proactive_vs_reactive_inhibition_manipulation

Varying stop-signal probability across blocks to separate anticipatory from stimulus-triggered control.

Pre-signal preparatory inhibition vs. post-signal reactive; different inhibition timing

Stop-Signal in Reaching/Saccade Tasks

hedvar_stop_signal__stop_signal_in_reaching_saccade_tasks

Non-button-press responses; extends to oculomotor and reaching domains.

Arm reaching or eye movement response; different motor effector

Context-Dependent Stop-Signal

hedvar_stop_signal__context_dependent_stop_signal

Environmental context predicts stop-signal probability.

Stop signal context varies; tests context-sensitive inhibition

Conditional Stop-Signal

hedvar_stop_signal__conditional_stop_signal

Stop signal presented but inhibition required only under certain conditions (e.g., specific signal color).

Inhibit only under specific conditions; conditional stopping logic

Cognitive processes

This task is designed to engage the following processes:

Key references

  • Logan, G. D., & Cowan, W. B. (1984). On the ability to inhibit thought and action: A theory of an act of control. Psychological Review, 91(3), 295-327. (DOI)

  • Aron, A. R., & Poldrack, R. A. (2006). Cortical and subcortical contributions to Stop signal response inhibition: Role of the subthalamic nucleus. Journal of Neuroscience, 26(9), 2424-2433. (DOI, PubMed)

  • Verbruggen, F., & Logan, G. D. (2008). Response inhibition in the stop-signal paradigm. Trends in Cognitive Sciences, 12(11), 418-424. (DOI, PubMed)

Further references

  • Verbruggen, F., Aron, A. R., Band, G. P., Beste, C., et al. (2019). A consensus guide to capturing the ability to inhibit actions and impulsive behaviors in the stop-signal task. eLife, 8, e46323. (DOI, PubMed)

  • Matzke, D., Curley, S., Gong, Q., & Heathcote, A. (2019). Bayesian modeling of stop-signal reaction time distributions. Psychological Review, 126(5), 663–722.

  • Skippen, P., Matzke, D., Heathcote, A., Fulham, W. R., Michie, P., & Karayanidis, F. (2019). Reliability of triggering inhibitory process is a better predictor of impulsivity than SSRT. Acta Psychologica, 192, 104–117. (DOI, PubMed)

  • Bissett, P. G., Hagen, M. P., Jones, H. M., & Poldrack, R. A. (2021). Design issues and solutions for stop-signal data from the Adolescent Brain Cognitive Development (ABCD) study. eLife, 10, e60185. (DOI, PubMed)