This repository contains code for a Delayed Match-to-Sample (DMS) visual task experiment using Psychtoolbox. Participants are presented with checkerboard stimuli, tasked with memorizing patterns, and required to identify the correct pattern after a delay.
Participants perform a Delayed Match-to-Sample (DMS) task as follows:
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Fixation Phase: A central fixation point (0.26° visual angle) is displayed for 2 seconds.
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Sample Presentation: A 4x4 checkerboard pattern (4.83° × 4.83°) is presented. 6 to 10 squares are yellow, while the rest are red. Participants are instructed to memorize the pattern.
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Delay Phase: The fixation point remains on screen for 0.5, 1, 2, 4, or 8 seconds (randomly selected per trial).
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Test Phase: Two checkerboards are presented side-by-side, 3° apart: One is identical to the sample (sample probe). The other differs by one swapped yellow/red square (location altered, not color). Participants press the left or right arrow keys to identify the correct pattern.
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Feedback: Correct Response: Green disc (1.93°). Incorrect Response: Red disc. No Response in 4 Seconds: Blue disc.
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Training Block: 10 trials for familiarization.
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Experimental Blocks: 6 blocks with 30 trials each (total: 180 trials). Each block includes 5 trials for each delay condition.
- Checkerboards remain on screen until: A response is made, or The 4-second response window expires.
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Customizable Task Parameters: Adjust number of trials, delay durations, square sizes, square color balances, and swap color numbers.
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Real-Time Feedback: Feedback is provided immediately after each response.
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Results Logging: Reaction times, performance, and square patterns and figures per each delay intervals and all are saved after each block.
- Software MATLAB: Required to run the code. Psychtoolbox: Used for visual stimuli presentation and input handling.
- Clone the repository:
git clone https://github.com/alimotahharynia/memory-checkerboard.git- Open MATLAB and navigate to the cloned repository folder.
- Run the main script:
run checkerboard- Follow on-screen instructions for the experiment.
If you use this task in your research, please cite our paper:
Hojjati F, Motahharynia A, Adibi A, Adibi I, Sanayei M. Correlative comparison of visual working memory paradigms and associated models. Sci Rep. 2024 Sep 6;14(1):20852. doi: 10.1038/s41598-024-72035-5. PMID: 39242827; PMCID: PMC11379810.
Pourmohammadi A, Motahharynia A, Shaygannejad V, Ashtari F, Adibi I, Sanayei M. Working memory dysfunction differs between secondary progressive and relapsing multiple sclerosis: Effects of clinical phenotype, age, disease duration, and disability. Mult Scler Relat Disord. 2023 Jan;69:104411. doi: 10.1016/j.msard.2022.104411. Epub 2022 Nov 12. PMID: 36436396.