___________________________________________________________________________________________________________________ *SPLIT VISUAL FIELD PARADIGM (SVFP)* ___________________________________________________________________________________________________________________ Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC Date: 07-17-2014 last updated: 02-28-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC Script Copyright © 02-28-2022 Millisecond Software ___________________________________________________________________________________________________________________ BACKGROUND INFO ___________________________________________________________________________________________________________________ This script runs the Split Visual Field Paradigm to study information processing loads across hemispheres. The implemented procedure is based on: Patel UJ, & Hellige JB. (2007). Benefits of interhemispheric collaboration can be eliminated by mixing stimulus formats that involve different cortical access routes. Brain Cognition, 63, 145-58. Epub 2006 Dec 15. ___________________________________________________________________________________________________________________ TASK DESCRIPTION ___________________________________________________________________________________________________________________ Participants are presented with 3 number stimuli on the screen: 2 numbers on the top of the screen - one in the upper left quadrant and one in the upper right quadrant- and one number either in the bottom left or the bottom right quadrant. Participants have to press the <SPACEBAR> if the number on the bottom is a match to one of the top displayed numbers. Numbers can either be digits or dice dots. The two top stimuli are always of the same format. Experiment 1 (parameters.version = 1): * Random sampling of numbers (without replacement) from numbers 1-6 * Matches = same number Experiment 2 (parameters.version = 2): * Random sampling of numbers (without replacement) from numbers 1-6 with following restrictions: never show 1 and 2 together (numbergroup 1), never present 3 and 4 together (numbergroup2), never present 5 and 6 together (numbergroup3) * Matches = number from the same numbergroup (NEVER the actual same number) ___________________________________________________________________________________________________________________ DURATION ___________________________________________________________________________________________________________________ the default set-up of the script takes appr. 60 minutes to complete ___________________________________________________________________________________________________________________ DATA FILE INFORMATION ___________________________________________________________________________________________________________________ The default data stored in the data files are: (1) Raw data file: 'splitvisualfield_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.ock. (parameter) version: 1 = Experiment1 set up (same numbers = the actual same numbers) 2 = Experiment2 set up (same numbers = number from same category) mixedcondition: "A": digits on top, dice Dot on bottom "B": dice Dot on top, digits on bottom (tested between participants) blockorder: 1 = Digits, Dots, Mixed 2 = Mixed, Digits, Dots 3 = Dots, Mixed, Digits practice: 0 = test trials; 1 = practice trials format: 'Digits', 'Dots', 'Mixed' match: 'Match' vs. 'NoMatch' side: lower number is on 'Left' or 'Right' sidematch: match is 'same' or 'across' or 'not applicable' (because there is no match) TopLeft: the stimulus presented on the top left TopRight: the stimulus presented on the top right Bottom: the stimulus presented on the bottom bottomPosition: stores the x-coordinate of the bottom stim response: the participant's response (scancode of response button): 57 = spacebar (= Match detected) 0 = no response correct: the correctness of the response (1 = correct; 0 = incorrect) latency: the response latency; measured from onset of digits/dots numbergroup: only needed if version = 2 is run: 1 = low and middle; (comparison numbers come from the low and middle spectrum: 1 or 2 AND 3 or 4) 2 = low and high; (comparison numbers come from the low and high spectrum: 1 or 2 AND 5 or 6) 3 = middle and high (comparison numbers come from the middle and high spectrum: 3 or 4 AND 5 or 6) (2) Summary data file: 'splitvisualfield_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) (parameter) version: 1 = Experiment1 set up (same numbers = the actual same numbers) 2 = Experiment2 set up (same numbers = number from same category) mixedcondition: "A": digits on top, dice Dot on bottom "B": dice Dot on top, digits on bottom (tested between participants) blockorder: 1 = Digits, Dots, Mixed 2 = Mixed, Digits, Dots 3 = Dots, Mixed, Digits No-Match Trials: list.ACC_Digits_NoMatch.itemCount: number of trials in which only digits without a match were presented propcorrect_digits_nomatch: prop correct for trials in which only digits without a match were presented meanerrorRT_digits_nomatch: mean error latency for incorrect responses in trials in which only digits without a match were presented list.ACC_Dots_NoMatch.itemCount: number of trials in which only dots without a match were presented propcorrect_dots_nomatch: prop correct for trials in which only dots without a match were presented meanerrorRT_dots_nomatch: mean error latency for incorrect responses in trials in which only dots without a match were presented list.ACC_Mixed_NoMatch.itemCount: number of trials in which mixed formats without a match were presented propcorrect_mixed_nomatch: prop correct for trials in which mixed formats without a match were presented meanerrorRT_mixed_nomatch: mean error latency for incorrect responses in trials in which mixed formats without a match were presented Match Trials: list.ACC_Digits_Match_Same.itemCount: number of digit only trials with a same side match propcorrect_digits_match_same: prop correct for digit only trials with a same side match meanrt_digits_match_same: mean correct latency digit only trials with a same side match list.ACC_Digits_Match_Across.itemCount: number of digit only trials with a cross side match propcorrect_digits_match_across: prop correct for digit only trials with a cross side match meanrt_digits_match_across: mean correct latency digit only trials with a cross side match list.ACC_Dots_Match_Same.itemCount: number of Dot only trials with a same side match propcorrect_Dots_match_same: prop correct for Dot only trials with a same side match meanrt_Dots_match_same: mean correct latency Dot only trials with a same side match list.ACC_Dots_Match_Across.itemCount: number of Dot only trials with a cross side match propcorrect_Dots_match_across: prop correct for Dot only trials with a cross side match meanrt_Dots_match_across: mean correct latency Dot only trials with a cross side match list.ACC_Mixed_Same.itemCount: number of mixed format trials with a same side match propcorrect_mixed_match_same: prop correct for mixed format trials with a same side match meanrt_mixed_match_same: mean correct latency mixed format trials with a same side match list.ACC_Mixed_Across.itemCount: number of mixed format trials with a cross side match propcorrect_mixed_match_across: prop correct for mixed format trials with a cross side match meanrt_mixed_match_across: mean correct latency mixed format trials with a cross side match ___________________________________________________________________________________________________________________ EXPERIMENTAL SET-UP ___________________________________________________________________________________________________________________ 3 format conditions: only digits (Digits), only dice Dots (Dots) or mixed (Mixed) formats are tested within participants in a blocked design. Block order is tested in a Latin Square design between participants. Mixed format has 2 variations (A or B): A: top numbers are digits and bottom number is a dice Dot B: top numbers are dice Dots and bottom number is a digit - Assignment is done by groupnumber (1-6) (see section EXPERIMENT for details on how participants are assigned to each condition) Test Blocks: - 64 trials per format block; 4 blocks of the same format run sequentially => 256 trials per format - 32 Match trials; 32 NoMatch trials - 16 of the 32 (Match/NoMatch) trials present the digit on the left (right) - 8 of the 16 Match trials with digits on the left (right) present the matching digit on the SAME monitor side; the other 8 present the matching digit on the opposite (ACROSS) side (=> 16 Same Match trials and 16 Across Match trials per block) Note: version 2: numbergroups are determined randomly with each numbergroup having the same probability of being sampled, the actual frequency of each of the 3 numbergroups might, however, differ. Practice Blocks: - 1 practice block before each format test condition - 24 trials - error feedback: present (1) the previous number set-up and (2) correct response (3) errorbeep Trial Sequence: - Fixation Cross: * present fixation cross for 2100ms (default) before onset of number array, * present short beep 1050ms (default) before onset of number array - Number Array (depending on format): numbers are presented for 195ms (default); participants have 2100ms to respond (by default, a new trial sequence starts either after a response or after 2100ms whichever comes first) - Practice only: Error Feedback trial ___________________________________________________________________________________________________________________ STIMULI ___________________________________________________________________________________________________________________ Digits: 1-6 Dice Dots: 1-6, provided by Millisecond Software (can be replaced under Editable Stimuli -> item.diceDots) USER INTERFACE Display of Stimuli (Size and Position) on-screen can be controlled via Editable Values. ___________________________________________________________________________________________________________________ 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). !!!Note: the default instructions are for Experiment 1 (version 1). If version 2 is run, the instructions need to be updated accordingly. ___________________________________________________________________________________________________________________ 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: /version: 1 = Experiment1 set up (same numbers = the actual same numbers) (default) 2 = Experiment2 set up (same numbers = number from same category) !!!NOTE: Instructions are provided for version 1; if version 2 is run the instructions need to be updated accordingly /responsekey: the response key (default: " " => SPACEBAR) Fine-tuning of UI: see Patel & Hellige (2007, p. 149) for specifics /fontsize_target: fontsize of the targets in screen height percentages (default: 10%) /pictureheight: height of dice Dot pictures in screen height percentages (default: 10%) /fontsize: fontsize of the fixation mark in screen height percentages (default: 5%) /upperleft_x- /upperleft_y: x,y coordinates (in % of screen height/width) for stimuli presented on the upper left side /lowerleft_x- /lowerleft_y: x,y coordinates (in % of screen height/width) for stimuli presented on the lower left side /upperright_x- /upperright_y: x,y coordinates (in % of screen height/width) for stimuli presented on the upper right side /lowerright_x- /lowerright_y: x,y coordinates (in % of screen height/width) for stimuli presented on the lower right side Durations: /getReadyDuration: duration (in ms) of the get-ready-trial (default: 3000ms) /responsewindow: time (in ms) participants have to respond to stim array presentation (default: 2100ms) /fixationduration: time (in ms) that fixation is presented before the beep (default: 1050ms -> 2100ms presentation of fixation cross before stim array is presented) /stimpresentation: time (in ms) the stim array is presented (default: 195ms)