Multi Source Interference Task (MSIT)

Background

The Multi-Source Interference Task (MSIT) is a cognitive-behavioral paradigm designed to measure executive function and attention by maximizing interference in neural processing, combining elements from classic interference tasks, including the Stroop, Eriksen flanker, and Simon tasks. The MSIT was developed by George Bush and colleagues in 2003 as a behavioral fMRI task to reliably activate the anterior cingulate cortex (ACC) and the cingulo-frontal-parietal attention network. They showed that the MSIT produced a substantial ~300 ms reaction time interference effect and consistently engaged the cingulo-frontal-parietal attention network.

MSIT trials present 3-character strings containing variations of the digits 1,2,3 or X. One of the characters differs from the others (e.g. "112"), and participants are instructed to identify as quickly as possible the different digit (e.g. 2) by pressing one of three horizontally located response keys. Control trials present character strings that contain two Xs and one digit. The digit is always presented a bit larger in size and its position in the string matches the position of its response button (e.g. 1XX). Interference strings, on the other hand, only contain digits (e.g. 112) and the target digit (e.g. 2) could be larger or smaller than the distractor digits. In addition, the position of the target digit never coincides with the position of the corresponding response button.

Mario Wenzel and colleagues leveraged the MSIT task in 2014 to explore how positive affect (PA) and specific self-regulation strategies influence cognitive flexibility when managing high-interference tasks. To this end they introduced a variant of the MSIT that introduced color as an additional interference characteristic (cMSIT): two digits are printed in the same color (e.g. green) and one is printed in a different color (e.g. red). The different color could be that of the target 322 (congruent) or that of a distractor item 322 (incongruent). They found that when participants who underwent a PA manipulation worked on a regular MSIT before the cMSIT, 'happier' participants performed worse on the cMSIT (group1) than neutral participants. On the other hand, 'happier' participants performed better on the cMSIT when a variant of the cMIST (= respond to color aspect) preceded it (group2). The results are consistent with the idea that PA is linked with greater cognitive flexibility and a broader attentional scope: group1 and group2 differed in the required cognitive flexibility (group2 required more) and attention devoted to the characteristic 'color' (this was new information only to group1). Whereas the goal stayed the same for group1, the increased attentional focus in PA participants was 'grabbed' by the new information 'color' thus lowering performance of PA participants. On the other hand, improved cognitive flexibility helped particularly the PA participants in group2 where color as 'new' information was no issue.

The MSIT script tasks (MSIT, cMSIT) provided in the Millisecond Library were originally all generously donated by Mario Wenzel and colleagues and subsequently updated by Millisecond. MSIT and cMSIT can be run with random or fixed trial orders.

Task Procedure

The MSIT and cMSIT procedures are similar. The following describes the current setup of the cMSIT. In the cMSIT participants work on 96 trials: 48 control trials, 24 color congruent trials and 24 color incongruent trials in a random order. The stimuli consist of 3-character strings containing digits 1,2,3 or X. Two characters are the same and one is different (Example: 212). The task is to press the response key (1,2,3) that corresponds to the target digit that is different than the other two (Example: 1). In addition, the target digit differs in size from the distractor characters and one of the characters is printed in a different color. Control trials present 3-character strings with one target digit and two X's. The position of the target digit is always congruent with the position of the response key (Examples: 1XX, X2X, XX3). In addition, the target digit is always larger and printed in a different color than the distractors. In color congruent and incongruent (multisource) trials, the stimuli consist of digits. The position of the target digit does not align with the position of the corresponding response key and the target digit can be larger OR smaller than the distractors. In addition, color congruent trials present target digits that also differ in color from the distractors, whereas color incongruent trials present one of the distractors in a different color. All target digits are presented equally often.

Each trial starts with a fixation cross for 500ms. The stimuli are presented for 2000ms which is also the response window. Accuracy feedback is provided for 500ms after each response.

What it Measures

The MSIT is a task designed to measure executive function and attention

Psychological domains

• Executive Control: Collection of "top-down" mental processes used to manage and regulate thoughts and actions
• Cognitive Flexibility: Shift to a new rule when the previous rule no longer applies
• Sustained Attention: Maintaining focus over a repetitive series of trials without 'drifting'

Main Performance Metrics

• MSIT Effect: The difference between interference and control trials, serves as a measure of self-control performance.
• Attention Effect: The difference in performance btw. congruent and incongruent color trials as a measure to attention spent on color information

Psychiatric Conditions

MSIT performance has been found to be impaired in the following patient groups

• Attention Deficit Hyperactivity Disorder (ADHD)
• Schizophrenia
• Posttraumatic Stress Disorder (PTSD)
• Obsessive-Compulsive Disorder (OCD)
• Major Depressive Disorder (MDD)
• Bipolar Disorder (BPD)

Test Variations

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Multi Source Interference Task (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.

Stins, J.F., Leeuwen, W.M.A. van & Geus, J.C.N. de (2005). The multi-source interference task: the effect of randomization. Journal of Clinical and Experimental Neuropsychology, 27, 711-717.

Bush, G., & Shin, L. M. (January 01, 2006). The Multi-Source Interference Task: an fMRI task that reliably activates the cingulo-frontal-parietal cognitive/attention network. Nature Protocols, 1, 1, 308-13.

Bush, G., Spencer, T. J., Holmes, J., Shin, L. M., Valera, E. M., Seidman, L. J., Makris, N., ... Biederman, J. (January 01, 2008). Functional magnetic resonance imaging of methylphenidate and placebo in attention-deficit/hyperactivity disorder during the multi-source interference task. Archives of General Psychiatry, 65, 1, 102-14.

Gaetz, W., Liu, C., Zhu, H., Bloy, L., & Roberts, T. P. (January 01, 2013). Evidence for a motor gamma-band network governing response interference. Neuroimage, 74, 245-53.

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.