Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 17, 2014
Last Modified: January 16, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
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.
60 minutes
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
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)
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)
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
Digits: 1-6
Dice Dots: 1-6, provided by Millisecond (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 are not original to the task. They are provided by Millisecond
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).
!!! the default instructions are for Experiment 1 (version 1). If version 2 is run, the instructions
need to be updated accordingly.
File Name: splitvisualfield_summary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| startDate | Date the session was run |
| startTime | Time the session was run |
| subjectId | Participant ID |
| groupId | Group number |
| sessionId | Session number |
| elapsedTime | Session duration in ms |
| completed | 0 = Test was not completed 1 = Test was completed |
| 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.accDigitsNoMatch.itemCount | Number of trials in which only digits without a match were presented |
| propCorrectDigitsNoMatch | Prop correct for trials in which only digits without a match were presented |
| meanErrorRTDigitsNoMatch | Mean error latency for incorrect responses in trials in which only digits without a match were presented |
| list.accDotsNoMatch.itemCount | Number of trials in which only dots without a match were presented |
| propCorrectDotsNoMatch | Prop correct for trials in which only dots without a match were presented |
| meanErrorRTDotsNoMatch | Mean error latency for incorrect responses in trials in which only dots without a match were presented |
| list.accMixedNoMatch.itemCount | Number of trials in which mixed formats without a match were presented |
| propCorrectMixedNoMatch | Prop correct for trials in which mixed formats without a match were presented |
| meanErrorRTMixedNoMatch | Mean error latency for incorrect responses in trials in which mixed formats without a match were presented Match Trials |
| list.accDigitsMatchSame.itemCount | Number of digit only trials with a same side match |
| propCorrectDigitsMatchSame | Prop correct for digit only trials with a same side match |
| meanrtDigitsMatchSame | Mean correct latency digit only trials with a same side match |
| list.accDigitsMatchACross.itemCount | Number of digit only trials with a cross side match |
| propCorrectDigitsMatchACross | Prop correct for digit only trials with a cross side match |
| meanrtDigitsMatchACross | Mean correct latency digit only trials with a cross side match |
| list.accDotsMatchSame.itemCount | Number of Dot only trials with a same side match |
| propCorrectDotsMatchSame | Prop correct for Dot only trials with a same side match |
| meanrtDotsMatchSame | Mean correct latency Dot only trials with a same side match |
| list.accDotsMatchACross.itemCount | Number of Dot only trials with a cross side match |
| propCorrectDotsMatchACross | Prop correct for Dot only trials with a cross side match |
| meanrtDotsMatchACross | Mean correct latency Dot only trials with a cross side match |
| list.accMixedSame.itemCount | Number of mixed format trials with a same side match |
| propCorrectMixedMatchSame | Prop correct for mixed format trials with a same side match |
| meanrtMixedMatchSame | Mean correct latency mixed format trials with a same side match |
| list.accMixedACross.itemCount | Number of mixed format trials with a cross side match |
| propCorrectMixedMatchACross | Prop correct for mixed format trials with a cross side match |
| meanrtMixedMatchACross | Mean correct latency mixed format trials with a cross side match |
File Name: splitvisualfield_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
| blockCode | Name of the current block |
| blockNum | Number of the current block |
| trialCode | Name of the current trial |
| trialNum | Number of the current trial |
| 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) |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| version | 1 = Experiment1 set up (same numbers = the actual same numbers) (default) 2 = Experiment2 set up (same numbers = number from same category) !!! Instructions are provided for version 1; if version 2 is run the instructions need to be updated accordingly | |
| responseKey | The response key | " " => SPACEBAR |
Fine-Tuning Of Ui: See Patel & Hellige (2007, P. 149) For Specifics |
||
| fontSizeTarget | Fontsize of the targets in screen height percentages | 10% |
| pictureHeight | Height of dice Dot pictures in screen height percentages | 10% |
| fontSize | Fontsize of the fixation mark in screen height percentages | 5% |
| upperLeftX:- | ||
| upperLeftY | X,y coordinates (in % of screen height/width) for stimuli presented on the upper left side | |
| lowerLeftX:- | ||
| lowerLeftY | X,y coordinates (in % of screen height/width) for stimuli presented on the lower left side | |
| upperRightX:- | ||
| upperRightY | X,y coordinates (in % of screen height/width) for stimuli presented on the upper right side | |
| lowerRightX:- | ||
| lowerRightY | 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 | 3000ms |
| responseWindow | Time (in ms) participants have to respond to stim array presentation | 2100ms |
| fixationDuration | Time (in ms) that fixation is presented before the beep | 1050ms -> 2100ms presentation of fixation cross before stim array is presented |
| stimPresentation | Time (in ms) the stim array is presented | 195ms |