___________________________________________________________________________________________________________________ MULTI SOURCE INTERFERENCE TASK (MSIT) - (with single-colored items, random order) ___________________________________________________________________________________________________________________ This script was generously provided by Mario Wenzel, Thomas Kubiak and Tamlin Conner to be shared via Millisecond Software's Script Library. Thank you! last updated: 02-25-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ 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 called in random order is similar to the procedure described in: 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. http://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. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ 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. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 2 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'msit_digit_random_raw*.iqdat' (a separate file for each participant) build: The specific Inquisit version used (the 'build') that was run computer.platform: the platform the script was run on (win/mac/ios/android) date, time: date and time script was run subject, group, with the current subject/groupnumber session: with the current session id blockcode, blocknum: the name and number of the current block (built-in Inquisit variable) trialcode, trialnum: the name and number of the currently recorded trial (built-in Inquisit variable) Note: trialnum is a built-in Inquisit variable; it counts all trials run; even those that do not store data to the data file such as feedback trials. Thus, trialnum may not reflect the number of main trials run per block. 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 correct: the correctness of the response (1 = correct; 0 = otherwise) latency: the response latency (measured from onset of stimulus, in ms) (2) Summary data file: ''msit_digit_random_summary*.iqdat' (a separate file for each participant) inquisit.version: Inquisit version run computer.platform: the platform the script was run on (win/mac/ios/android) startDate: date script was run startTime: time script was started subjectid: assigned subject id number groupid: assigned group id number sessionid: assigned session id number elapsedTime: time it took to run script (in ms); measured from onset to offset of script completed: 0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run) 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 ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ - This script runs 39 trials in random order: 15 uni trials (3 with control images), 24 multi trial - 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 ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ 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 ___________________________________________________________________________________________________________________ instructions are provided by Mario Wenzel, Thomas Kubiak and Tamlin Conner and can be edited under EDITABLE CODE -> Editable Instructions ___________________________________________________________________________________________________________________ EDITABLE CODE ___________________________________________________________________________________________________________________ check below for (relatively) easily editable parameters, stimuli, instructions etc. Keep in mind that you can use this script as a template and therefore always "mess" with the entire code to further customize your experiment.