Credits:
The original script was generously provided by Mario Wenzel, Thomas Kubiak and Tamlin Conner to be shared via Millisecond
Software's Script Library. Thank you!
Software's Script Library. Thank you!
Last Modified: May 05, 2026 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements a Multi Source Interference Task (cMSIT). The MSIT was originally designed by Bush et al (1998) as a behavioral fMRI task to assess the functional integrity of the acc subdivision in selected neuropsychiatric disorders. According to Bush et al the MSIT combines multiple dimensions of cognitive interference such as flanker, and Stroop interference.
The implemented procedure in this script with white stimuli and a random order of stimuli is similar to the procedure described in Wenzel et al (2013).
Wenzel, M., Kubiak, T., & Conner, T. S. (2013). Positive affect and self-control: Attention to self-control demands mediates the influence of positive affect on consecutive self-control. Cognition and Emotion. https://dx.doi.org/10.1080/02699931.2013.851069
Original MSIT: Bush, G., Shin, L.M., Holmes, J., Rosen, B.R., & Vogt, B.A. (2003). The Multi-Source Interference Task: Validation study with fMRI in individual subjects. Molecular Psychiatry, 8, 60–70.
2 minutes
Participants are presented stimuli consisting of 3 digits (1, 2, 3s) (or 1 digit and 2 X's = controls). One of the digits is different from the flanking digits and differs in size. Participants are asked to press a response button (1, 2, 3) as fast as possible to report which digit was different.
- This script runs 39 trials (3 control, 12 uni-source, 24 multi-source) in a random order.
- response buttons: 1, 2, 3 on keyboard and/or numeric pad
Trial Sequence:
- fixation cross for 500ms
- stimulus presented for 2000ms
- accuracy feedback 500ms after response or stimulus timeout
all stimuli are provided by Mario Wenzel, Thomas Kubiak and Tamlin Conner
control (target always printed larger): 3 (1 fontsize x 1 identities of flanking letters x 3 target digits x 1 possible positions of target digit)
uni-source (target position and response key position are congruent): 12 (2 fontsizes x 2 identities of flanking numbers x 3 target digits x 1 possible positions of target digit)
multi-source (target position and response key position are incongruent): 24 (2 fontsizes x 2 identities of flanking numbers x 3 target digits x 2 possible positions of target digit)
instructions are provided by Mario Wenzel, Thomas Kubiak and Tamlin Conner
and can be edited under EDITABLE CODE -> Editable Instructions
File Name: msit_digit_random_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| propCorrect | Proportion correct overall |
| meanRT | Mean latency (in ms) of all correct responses |
| std | Standard deviation of all correct latencies |
| medianRT | Median latency (in ms) of all correct responses |
| propCorrectControl | Proportion correct responses in control trials |
| propCorrectUni | Proportion correct responses in uni trials |
| propCorrectMulti | Proportion correct responses in multi trials |
| propCorrectInterference | Proportion correct responses in interference trials (across uni and multi trials) |
| msitEffectAcc | The difference between control and multi interference trial performance MSIT effect = propCorrectControl - propCorrectMulti (positive: control trials had higher proportion correct) |
| meanCorrRTControl | Mean correct response time (in ms) in control trials |
| meanCorrRTUni | Mean correct response time (in ms) in uni trials |
| meanCorrRTMulti | Mean correct response time (in ms) in multi trials |
| meanCorrRTInterference | Mean correct response time (in ms) in interference trials (across uni and multi trials) |
| msitEffectRT | The difference between control and multi trial correct latencies MSIT effect = meanCorrRTMulti - meanCorrRTControl (positive: control trials were faster) |
File Name: msit_digit_random_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| trialCounter | Tracks the number of trials run |
| interferenceSource | Uni = interfering digits but target digit's position and response key are congruent multi = interfering digits AND target digit's position and response key are incongruent control = no interfering digits, no interfering position and response key incongruency |
| controlTrial | 1 = trial is a controltrial 0 = trial is an interference trial |
| targetSize | L(arge) vs. s(mall) |
| corrResp | The correct response key |
| stimulusItem.1-stimulusItem.2 | The presented stimuli in order of trial presentation |
| response | The participant's response (scancode of response key) 2,79 => 1 3, 80 => 2 4, 81 => 3 |
| responseText | Stores the actual label of the response key pressed ("1", "2", "3") |
| correct | The correctness of the response (1 = correct; 0 = otherwise) |
| latency | The response latency (measured from onset of stimulus, in ms) |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Timing Parameters |
||
| readyDuration | The duration (in ms) of the get-ready-trial | 5000 |
| fixationDuration | The duration (in ms) of the fixation stim | 500 |
| stimPresentationDurationMS | The duration (in ms) that the stims are presented (= response timeout) | 2000 |
| feedbackDuration | The duration (in ms) of the feedback stim | 500 |