___________________________________________________________________________________________________________________ *DOT MOTION DISPLAY - CONSTANT STIMULI PROCEDURE* ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 03-10-2021 last updated: 01-19-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 01-19-2023 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This helper script implements a constant stimuli procedure. It was pogrammed for the lab of Dr. Aaron Seitz for a validation study conducted by Kimia Yaghoubi. Reference: Yaghoubi, K. C., Kabbara, S., Arian, S., Kobaissi, H., Peters, M. A. K., & Seitz, A. R. (2022). Comparing random dot motion in MATLAB vs. Inquisit Millisecond. Frontiers in Psychology, 13, 1035518–1035518. https://doi.org/10.3389/fpsyg.2022.1035518 ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 12 minutes to complete __________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'rdkt_constantstimuli_dynamicdots_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) display.canvasHeight, display.canvasWidth: the pixel width and height of the active canvas used on the current computer display.refreshrate, display.refreshinterval: refreshrate and interval of the current monitor (see also values.dotposition) date, time, date and time script was run subject/SUBJECT with the current subject number (both built-in and custom) session/Session: with the current session id (both built-in and custom) /Run: the current run number 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. //constant settings: /numberOfDots = 100 //sets the total number of dots on the screen (MAX: 100) /dotSize = 1.15% //the relative size of the dots (relative to canvas height which is 100%) /radius = 40% //sets the radius of the background circle relative to canvas height (Max = 50%) /speed = 1 //calculated as %screen height displacement per 'frame' /dotPositionDuration = display.refreshinterval //the duration (in ms) that a dot stays in one position (Example: 60Hz monitor has refreshinterval of 16.67ms) /blockCounter_perRun: blockcounter (there should be blocks for each run = 160 trials) /trialCounter: counts the trials (max: 160) run //IVs: /coherence: the currently selected coherence /angle: the currently selected angle (rotation is counterclockwise) /stimDuration: the currently selected stim duration /corrQuadrant: the screen quadrant of the correct response coordinates (counterclockwise) top: 1 (right: angles 360/0-89), 2 (left: angles 90-179) bottom: 3 (left: angles 180-269), 4 (right: angles 270-359) //DVs: /responseCoordinatesQuadrant: the screen quadrant of the given response coordinates response: the participant's response (here: selection of correctAxis vs. incorrectAxis) values.response_x, values.response_y: the pixel responses for the vertical (y) and horizontal (x) coordinates on the active canvas expressions.response_angle_indegrees: the calculated response angle (Note: 0degrees is W->E, counterclockwise) expressions.angleDiff: the difference between response angle and direction angle correct: 1 = correct; 0 = error Note: a response is correct if expressions.angleDiff is < 22.5 latency: the response latency (in ms) //debug checks (Note: for 100 dots only): values.coherenceAssignmentLists_valid: 1 = position lists 2-121 all contain the adequate number of signal dots that will be assigned to the 100 dots 0 = at least one position list does not contain the adequate number of signal dots values.assignedNumberSignalDots_perframe_valid: 1 = across the 100 dots, each position 2-121 contains the adequat number of signal dots 0 = at least for one position the number of signal dots was not adequat * separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section "DATA" and follow further instructions ___________________________________________________________________________________________________________________ EXPERIMENTAL SETUP ___________________________________________________________________________________________________________________ This helper script implements a constant stimuli procedure. The main procedure runs 160 trials each (160 trials = 1 run). 1 block: runs 80 trials (repeated twice per run) runs 10 coherence values x 4 direction angles x 2 stim durations (order randomly determined) Trial Sequence: - Fixation Dot 250ms - stimulus Display (200ms vs. 800ms) - responseDelay (500ms) - response Display (max. 4000ms): valid response is a mouse click on the display (if selected angle is within 22.5degress of the directional angle, the response is scored as correct) - iti (400ms) DEBBUGGING NOTE: This script has a built-in debugging mode (see editable parameter.debugmode) Purpose of debugblock: - check that the dots move correctly given the selected direction - check that accuracy procedure of the response works In debugmode: - script runs 1 block of 4 trials (each of the four directions) - each trial presents 100 dots moving with 100% coherence in the selected direction (can be edited to a different value if needed) - the directional cross appears - response is simply a button down response: if it's within 22.5degrees of the selected direction the trial is scored as correct ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ generated by the script DOT DISPLAYS: Each dot (example: 100 dots) hops through max.121 positions and for each of those 121 positions a certain number of these 100 dots are randomly selected to be signal dots (move coherently) and the remaining dots are assigned to be noise dots (are randomly placed). The number of signal vs. noise dots per position depends on the currently tested coherence. Thus a dot that moves as a signal dot from position2 to position3 might randomly be selected to be a random noise dot for position4 (see Pilly & Seitz, 2009, figure1, p.3: "signal dots are recruited afresh from each frame to the next". However, for each position, the same number of dots are recruited to be signal dots. Directional cross The directional cross is generated by two rectangles rotated by the directional angle with an invisible (gray) rectangle to cover the cross section. ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ provided by Kimia Yaghoubi ___________________________________________________________________________________________________________________ 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. The parameters you can change are: