Return to the Split Visual Field Task page
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								*SPLIT VISUAL FIELD PARADIGM (SVFP)*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 07-17-2014
last updated:  10-30-2019 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 10-30-2019 Millisecond Software

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BACKGROUND INFO 	
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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.

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TASK DESCRIPTION	
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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  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)

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DURATION 
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the default set-up of the script takes appr. 60 minutes to complete

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DATA FILE INFORMATION 
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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
script.sessionid:					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. 
										
										
parameters.version:				1 = Experiment1 set up (same numbers = the actual same numbers)
								2 = Experiment2 set up (same numbers = number from same category)
									
values.mixedcondition:				"A": digits on top, dice Dot on bottom
								"B": dice Dot on top, digits on bottom (tested between participants)
									
values.blockorder:					1 = Digits, Dots, Mixed
								2 = Mixed, Digits, Dots
								3 = Dots, Mixed, Digits
									
values.practice:					0 = test trials; 
								1 = practice trials
									
values.format:					'Digits', 'Dots', 'Mixed'
values.match:					'Match' vs. 'NoMatch'
values.side:						lower number is on 'Left' or 'Right'
values.sidematch:					match is 'same' or 'across' or 'not applicable' (because there is no match)
values.TopLeft:					the stimulus presented on the top left
values.TopRight:					the stimulus presented on the top right
values.Bottom:					the stimulus presented on the bottom
values.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

values.numbergroup:				only needed if values.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)

computer.platform:				the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:					assigned group id number
script.sessionid:					assigned session id number
script.elapsedtime:				time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
								1 = script was completed (all conditions run)
									
parameters.version:				1 = Experiment1 set up (same numbers = the actual same numbers)
								2 = Experiment2 set up (same numbers = number from same category)
									
values.mixedcondition:				"A": digits on top, dice Dot on bottom
								"B": dice Dot on top, digits on bottom (tested between participants)
									
values.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									
expressions.propcorrect_digits_nomatch: 			prop correct for trials in which only digits without a match were presented
expressions.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									
expressions.propcorrect_dots_nomatch: 				prop correct for trials in which only dots without a match were presented	
expressions.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								
expressions.propcorrect_mixed_nomatch: 			prop correct for trials in which mixed formats without a match were presented	
expressions.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
expressions.propcorrect_digits_match_same:			prop correct for digit only trials with a same side match
expressions.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
expressions.propcorrect_digits_match_across:		prop correct for digit only trials with a cross side match
expressions.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
expressions.propcorrect_Dots_match_same:			prop correct for Dot only trials with a same side match
expressions.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
expressions.propcorrect_Dots_match_across:			prop correct for Dot only trials with a cross side match
expressions.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
expressions.propcorrect_mixed_match_same:			prop correct for mixed format trials with a same side match
expressions.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
expressions.propcorrect_mixed_match_across:		prop correct for mixed format trials with a cross side match
expressions.meanrt_mixed_match_across:			mean correct latency mixed format trials with a cross side match

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EXPERIMENTAL SET-UP 
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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

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STIMULI
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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. 

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INSTRUCTIONS 
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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.

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EDITABLE CODE 
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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:						scancode of the response key
											Note: scancodes under Tools -> Keyboard Scancodes (default: 57)
/responsekey_label:					label of the response key (default: )


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)