___________________________________________________________________________________________________________________ VISUAL SEARCH (with eyetracking component) ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 06-19-2017 last updated: 03-02-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 03-02-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script implements a basic visual search paradigm based on: Motter,B.C., & Simoni, D.A. (2008). Changes in the functional visual field during search with and without eye movements. Vision Research 48 (2008) 2382–2393. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are asked to check letter arrays of green and red L's and T's (in 6 different spatial rotations) of varying array sizes (6, 12, 24, 48) for a target letter. The target letter shares one feature with each distractor letter ("conjunction style search array"). For example, if the target letter is a red L, the distractor letters are red T's and green L's. Half the arrays contain the target. ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 25 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'visualsearch_letters_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) canvasheight_inmm: the height of the screen canvas used for the script in mm canvaswidth_inmm: the width of the screen canvas used for the script in mm 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. arraySize: stores the number of stims presented (6, 12, 24, 48) targetPresent: 1 = target presented in array; 0 = otherwise picture.target.hposition: the horizontal screen position (in % of canvas width) picture.target.vposition: the vertical screen position (in % of canvas height) targetDistance: calculates the distance (in %) from the target stim to the center (fixation cross) relative to the screen canvas (portion of monitor used for stimulus display) (only valid for 'Target Present' trials) -> the value can be converted to absolute measurements by using 'canvasheight_inmm/canvaswidth_inmm' canvasRatio: calculates the ratio of canvas (=the part of the screen that is used by the script) height to height of monitor(in %) currentTarget: stores the itemnumber of the current target item cue response: the participant's response (scancode of response button: 18(E); 23(I)) Response: translates scancode of response button into response: 'yes' vs. 'no responseCategory: accuracy of response: 1 = correct response; 0 = otherwise latency: the response latency (in ms); measured from: onset of stims (after presentation of cue) (2) Summary data file: 'visualsearch_letter_et_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) canvasheight_inmm: the height of the screen canvas used for the script in mm canvaswidth_inmm: the width of the screen canvas used for the script in mm 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) ACCoverall: overall proportion correct (across all test trials) meanRT: mean latency (in ms) across all correct test trials ACCtargetPresent_6: proportion correct of trials with 6 stimuli where the target is present RTtargetPresent_6: mean correct latency (in ms) of trials with 6 stimuli where the target is present ACCtargetAbsent_6: proportion correct of trials with 6 stimuli where the target is absent RTtargetAbsent_6: mean correct latency (in ms) of trials with 6 stimuli where the target is absent ACCtargetPresent_12: proportion correct of trials with 12 stimuli where the target is present RTtargetPresent_612: mean correct latency (in ms) of trials with 12 stimuli where the target is present ACCtargetAbsent_12: proportion correct of trials with 12 stimuli where the target is absent RTtargetAbsent_12: mean correct latency (in ms) of trials with 12 stimuli where the target is absent ACCtargetPresent_24: proportion correct of trials with 24 stimuli where the target is present RTtargetPresent_24: mean correct latency (in ms) of trials with 24 stimuli where the target is present ACCtargetAbsent_24: proportion correct of trials with 24 stimuli where the target is absent RTtargetAbsent_24: mean correct latency (in ms) of trials with 24 stimuli where the target is absent ACCtargetPresent_48: proportion correct of trials with 48 stimuli where the target is present RTtargetPresent_48: mean correct latency (in ms) of trials with 48 stimul]i where the target is present ACCtargetAbsent_48: proportion correct of trials with 48 stimuli where the target is absent RTtargetAbsent_48: mean correct latency (in ms) of trials with 48 stimuli where the target is absent * separate data files: to change to one data file for all participants (on Inquisit Lab only), go to section "DATA" and follow further instructions (3) Eyetracker data file: Marker info: translation of marker code (markers can have up to 9 digits) 1st digit: 1 = practice trial; 2 = test trial 2-3rd digit: trialcount (for easier cross referencing with raw data file) 4th digit: 1 = fixation onset; 2 = cue onset; 3 = array onset; 4 = response onset; 5 = feedback onset (if feedback is provided) 5th digit: 1 = greenL; 2 = redL; 3 = greenT; 4 = redT 6th digit: 1 = 6 stims (practice: 4); 2 = 12 stims (practice: 16); 3 = 24 stims (only test); 4 = 48 stims (only test) 7th digit: 1 = 0deg rotated target; 2 = 60deg rotated target; 3 = 120deg rotated; 4 = 180deg; 5 = 240deg; 6 = 300deg 8th digit: 1 = target present; 0 = target absent 9th digit: 1 = response was correct; 0 = response was incorrect Example: 105422511 => 1|05|4|2|2|5|1|1 1 => practice 05 => 5th trial in data file (practice) 4 => response onset 2 => redL 2 => 12 stims 5 => target 240deg rotation 1 => target present, 1 => correct response ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ Practice: default - 24 practice trials (6 per target category, e.g. 'green L', order is randomized) - each possible target is used once per target category - random selection) - 2 different array sizes per target category (4 stims vs. 16 stims), random selection - half the trials (12) have the target present (order of 'target present' vs. 'target absent' randomized) - provides performance feedback Test: default 2 target colors (green vs. red) x 2 target letters (L vs. T) x 4 array sizes (6, 12, 24, 48) x 2 target condition (present vs. absent) x 6 reps = 192 trials, tested in a full, mixed design - the 4 target categories (color x letter) are selected in random order - in each of the 4 target conditions (color x letter, e.g. 'green L'): - equal frequency of the 4 possible array sizes (array size is randomly determined) - half the targets are present, half the targets are absent (randomly selected) => balanced across the 4 different set sizes (6 targets present/6 targets absent for each of the 4 set sizes) Note: Motter & Simoni (2008) ran sessions of 240 trials. - Target Selection: - The target stimulus is selected randomly from the 6 possible rotations (see under STIMULI) for the given target condition) - each rotation is selected equally often => each target rotation is run 8 times per target condition - Distractor Selection: - half the distractors are selected from the opposite color (but same letter) -> the appropriate item numbers are selected randomly without replacement (repetitions are possible, once all 6 possible stims were selected) - the remaining distractors are selected from the same color (but different letter) -> the appropriate item numbers are selected randomly without replacement (repetitions are possible, once all 6 possible stims were selected) - Stim Locations: - 48 possible stim locations (7x7 matrix, with fixation cross in the center) - stim locations are randomly (without replacement) assigned to each of the stims (including target) - stim locations reset before each new trial Canvas: By default, the canvas (=part of the screen used by this script) is the biggest square (width = height) that can be established on the current monitor. The canvas can be further manipulated by explicitly forcing a specific canvas size and/or by forcing a specific windowsize (see section DEFAULTS for more info) Trial Sequence: Fixation Cross (until Spacebar press) -> Cue (default: 1000ms)->Array (max: 7000ms) ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ provided by Millisecond Software - can be edited under section Editable Stimuli Note: each target category (green L, red L, green T, red T) can be represented by 1 of 6 orientations: the letter was rotated 6 times by increments of 60deg ___________________________________________________________________________________________________________________ INSTRUCTIONS ___________________________________________________________________________________________________________________ Instructions are not original to the task. They are provided by Millisecond Software as htm/html pages and can be edited by changing the provided htm/html files. To edit htm/html-files: open the respective documents in simple Text Editors such as TextEdit (Mac) or Notepad (Windows). ___________________________________________________________________________________________________________________ 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: /cueDuration: duration (in ms) of cue (default: 1000ms) /responseWindow: duration (in ms) of response window (default: 7000ms) /spacebarReminder: the delay (in ms) after which a spacebar-response reminder is presented (default: 2000ms) /feedbackDuration: duration (in ms) of feedback duration (default: 2000ms) /readyDuration: duration (in ms) of get-ready trial (default: 3000ms) /picSize: proportional sizing of images in percentage of canvas height (default: 10%) /fixationSize: proportional sizing of fixation cross in percentage of canvas height (default: 10%) Response Keys: /yesKey: the yes-key scancode (default: E); the left response key /noKey: the no-key scancode (default: I); the right response key