Stop Signal Reaction Time
Estimate integration-method SSRT using linearly interpolated go-RT quantiles and max-RT omission replacement; negative estimates are preserved and flagged, not validated as race-model compatible.
Description
The stop-signal integration estimate subtracts average stop delay from a go-response quantile selected by stop-response probability.
The stop-signal integration estimate subtracts average stop delay from a go-response quantile selected by stop-response probability. Handling omitted go trials affects the quantile.
The tool returns responseProbability (response probability); integrationQuantileMs (integration quantile ms); meanStopSignalDelayMs (mean stop signal delay ms); estimatedSsrtMs (estimated ssrt ms); negativeEstimate (negative estimate). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Stop Signal Reaction Time
Use Stop Signal Reaction Time when you already have goReactionTimesMs, goOmissions, failedStopTrials, totalStopTrials, stopSignalDelaysMs and want responseProbability, integrationQuantileMs, meanStopSignalDelayMs, estimatedSsrtMs, negativeEstimate. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Stop Signal Reaction Time and understand its results
- Enter goReactionTimesMs, goOmissions, failedStopTrials, totalStopTrials, stopSignalDelaysMs using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read responseProbability, integrationQuantileMs, meanStopSignalDelayMs, estimatedSsrtMs, negativeEstimate. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| goReactionTimesMs | Go reaction times ms | list of number | Required |
| goOmissions | Go omissions | integer | Required |
| failedStopTrials | Failed stop trials | integer | Required |
| totalStopTrials | Total stop trials | integer | Required |
| stopSignalDelaysMs | Stop signal delays ms | list of number | Required |
Use an interior failed-stop fraction and one nonnegative delay per stop trial. Replace omissions with the maximum successful go RT; quantiles use linear interpolation at (N−1)p.
SSRT = quantile(goRTs with omissions replaced by maximum, failedStops/totalStops) − mean(stopDelays) The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"goReactionTimesMs": [
100,
200,
300,
400
],
"goOmissions": 0,
"failedStopTrials": 2,
"totalStopTrials": 4,
"stopSignalDelaysMs": [
50,
50,
50,
50
]
},
"output": {
"responseProbability": 0.5,
"integrationQuantileMs": 250,
"meanStopSignalDelayMs": 50,
"estimatedSsrtMs": 200,
"negativeEstimate": false
}
}Limitations and assumptions
Negative estimates are retained and flagged. The race-model assumptions and experimental-quality criteria are not verified.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
Posner Cueing Effect: Measure invalid-minus-valid Posner cueing benefit after correct-trial and caller-supplied RT-window exclusions; both conditions must remain observed. Visual Search Slope: Aggregate correct-trial visual-search RTs by set size and fit equally weighted condition means; signed slopes are retained and no serial/parallel search diagnosis is asserted.
Methodological background: A consensus guide to capturing the ability to inhibit actions and impulsive behaviors in the stop-signal task.1
References
Similar or alternative tools
- Posner Cueing Effect
Measure invalid-minus-valid Posner cueing benefit after correct-trial and caller-supplied RT-window exclusions; both conditions must remain observed.
- Visual Search Slope
Aggregate correct-trial visual-search RTs by set size and fit equally weighted condition means; signed slopes are retained and no serial/parallel search diagnosis is asserted.