Stop-Signal Task¶
HED Task ID: hedtsk_stop_signal
Also known as: SST, Stop Task
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¶
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¶
Variation |
Description |
Justification |
|---|---|---|
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 |
Predetermined SSDs; simpler but less efficient for SSRT estimation. |
Non-adaptive fixed delays; different trial structure |
Stop-Change Task |
Stop signal requires switching to alternative response rather than pure inhibition. |
Stop signal replaced by change signal; different inhibition-and-substitute |
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 |
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 |
Non-button-press responses; extends to oculomotor and reaching domains. |
Arm reaching or eye movement response; different motor effector |
Context-Dependent Stop-Signal |
Environmental context predicts stop-signal probability. |
Stop signal context varies; tests context-sensitive inhibition |
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 engages the following cognitive processes:
Key references¶
{‘authors’: ‘Logan, G. D., & Cowan, W. B.’, ‘year’: 1984, ‘title’: ‘On the ability to inhibit thought and action: A theory of an act of control.’, ‘venue’: ‘Psychological Review’, ‘venue_type’: ‘journal’, ‘journal’: ‘Psychological Review’, ‘volume’: ‘91’, ‘issue’: ‘3’, ‘pages’: ‘295-327’, ‘doi’: ‘10.1037/0033-295x.91.3.295’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1037/0033-295x.91.3.295’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Aron, A. R., & Poldrack, R. A.’, ‘year’: 2006, ‘title’: ‘Cortical and Subcortical Contributions to Stop Signal Response Inhibition: Role of the Subthalamic Nucleus’, ‘venue’: ‘The Journal of Neuroscience’, ‘venue_type’: ‘journal’, ‘journal’: ‘The Journal of Neuroscience’, ‘volume’: ‘26’, ‘issue’: ‘9’, ‘pages’: ‘2424-2433’, ‘doi’: ‘10.1523/jneurosci.4682-05.2006’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1523/jneurosci.4682-05.2006’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Verbruggen, F., & Logan, G. D.’, ‘year’: 2008, ‘title’: ‘Response inhibition in the stop-signal paradigm’, ‘venue’: ‘Trends in Cognitive Sciences’, ‘venue_type’: ‘journal’, ‘journal’: ‘Trends in Cognitive Sciences’, ‘volume’: ‘12’, ‘issue’: ‘11’, ‘pages’: ‘418-424’, ‘doi’: ‘10.1016/j.tics.2008.07.005’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Verbruggen, F., & Logan, G. D. (2008). Response inhibition in the stop-signal paradigm. Trends in Cognitive Sciences, 12(11), 418-424.’, ‘url’: ‘https://doi.org/10.1016/j.tics.2008.07.005’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
Recent references¶
{‘authors’: ‘Verbruggen, F., Aron, A. R., Band, G. P., Beste, C., Bissett, P. G., Brockett, A. T., Brown, J. W., Chamberlain, S. R., Chambers, C. D., Colonius, H., Colzato, L. S., Corneil, B. D., Coxon, J. P., Dupuis, A., Eagle, D. M., Garavan, H., Greenhouse, I., Heathcote, A., Huster, R. J., Jahfari, S., Kenemans, J. L., Leunissen, I., Li, C. R., Logan, G. D., Matzke, D., Morein-Zamir, S., Murthy, A., Paré, M., Poldrack, R. A., Ridderinkhof, K. R., Robbins, T. W., Roesch, M., Rubia, K., Schachar, R. J., Schall, J. D., Stock, A., Swann, N. C., Thakkar, K. N., van der Molen, M. W., Vermeylen, L., Vink, M., Wessel, J. R., Whelan, R., Zandbelt, B. B., & Boehler, C. N.’, ‘year’: 2019, ‘title’: ‘A consensus guide to capturing the ability to inhibit actions and impulsive behaviors in the stop-signal task’, ‘venue’: ‘eLife’, ‘venue_type’: ‘journal’, ‘journal’: ‘eLife’, ‘volume’: ‘8’, ‘issue’: None, ‘pages’: None, ‘doi’: ‘10.7554/elife.46323’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.7554/elife.46323’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Weigard, A., Heathcote, A., Matzke, D., & Huang-Pollock, C.’, ‘year’: 2019, ‘title’: ‘Cognitive Modeling Suggests That Attentional Failures Drive Longer Stop-Signal Reaction Time Estimates in Attention Deficit/Hyperactivity Disorder’, ‘venue’: ‘Clinical Psychological Science’, ‘venue_type’: ‘journal’, ‘journal’: ‘Clinical Psychological Science’, ‘volume’: ‘7’, ‘issue’: ‘4’, ‘pages’: ‘856-872’, ‘doi’: ‘10.1177/2167702619838466’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Matzke, D., Curley, S., Gong, Q., & Heathcote, A. (2019). Bayesian modeling of stop-signal reaction time distributions. Psychological Review, 126(5), 663–722.’, ‘url’: ‘https://doi.org/10.1177/2167702619838466’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Skippen, P., Matzke, D., Heathcote, A., Fulham, W. R., Michie, P., & Karayanidis, F.’, ‘year’: 2019, ‘title’: ‘Reliability of triggering inhibitory process is a better predictor of impulsivity than SSRT’, ‘venue’: ‘Acta Psychologica’, ‘venue_type’: ‘journal’, ‘journal’: ‘Acta Psychologica’, ‘volume’: ‘192’, ‘issue’: None, ‘pages’: ‘104-117’, ‘doi’: ‘10.1016/j.actpsy.2018.10.016’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1016/j.actpsy.2018.10.016’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Bissett, P. G., Hagen, M. P., Jones, H. M., & Poldrack, R. A.’, ‘year’: 2021, ‘title’: ‘Design issues and solutions for stop-signal data from the Adolescent Brain Cognitive Development (ABCD) study’, ‘venue’: ‘eLife’, ‘venue_type’: ‘journal’, ‘journal’: ‘eLife’, ‘volume’: ‘10’, ‘issue’: None, ‘pages’: None, ‘doi’: ‘10.7554/elife.60185’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.7554/elife.60185’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}