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											*REDUNDANT SIGNAL TASK (RST)*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 10-02-2013
last updated:  03-11-2020 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC

Script Copyright © 03-11-2020 Millisecond Software

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BACKGROUND INFO 	
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This script implements the Redundant Signal Task by Fillmore (2010), a task to investigate
the information processing advantage of receiving redundant information via several 
senory pathways (visual + aural).

Reference:

Mark T. Fillmore, M.T. (2010). Processing Bimodal Stimulus Information Under Alcohol: Is There 
a Risk to Being Redundant? Experimental and Clinical Psychopharmacology, 18, 429–435.

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TASK DESCRIPTION
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Participants perform a simple categorization task on 2 letters and/or 2 tones. The letters and/or tones
are presented at three random time intervals after a fixation cross disappears from the screen. Participants are 
asked to press one key for letter1/tone1 (here: O and high tone) and another key for letter2/tone2 
(here: X and low tone).
There are 3 blocks: one block presents only the letters, one block presents only the tones, and one
block presents letters and tones simultaneously ("redundant" condition).

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DURATION 
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the default set-up of the script takes appr. 25 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: 'redundantsignaltask_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.								
									
									
values.practice:					0 = test trials; 1 = practice trials;
values.soa:							current SOA
values.target:						1 = 0 and/or high tone; 2 = X and/or low tone

response:							the participant's response (scancode of response button)
									30 = A
									38 = L
									0 = no response

values.responseCat:					the interpreted key response: "O/low", "X/high", "no response"

correct:							the correctness of the response
latency: 							the response latency (in ms); measured from onset of stim

values.valid:						1 = valid (latencies in acceptable range); 
									0 = invalid (latencies outside acceptable range)
									

(2) Summary data file: 'redundantsignaltask_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)
									
expressions.correctprop_overall:		proportion of correct responses (valid trials only) across all test trials				
expressions.meanrt_overall:				mean latency of correct responses (valid trials only) across all test trials									
									
expressions.correctprop_visual:			proportion of correct responses (valid trials only) for visual-only trials				
expressions.meanrt_visualonly:			mean latency of correct responses (valid trials only) for visual-only trials									

expressions.correctprop_audio:			proportion of correct responses (valid trials only) for audio-only trials				
expressions.meanrt_audioonly:			mean latency of correct responses (valid trials only) for audio-only trials

expressions.correctprop_redundant:		proportion of correct responses (valid trials only) for combined trials				
expressions.meanrt_redundant:			mean latency of correct responses (valid trials only) for combined trials

expressions.percentinvalid:				percent invalid test trials (latencies outside specified boundaries)

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EXPERIMENTAL SET-UP 
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type of stimuli presented (visual only vs. audio only vs. both) tested within subjects in a blocked design

* Experimental Blocks:
- 3 blocks, order counterbalanced (latin square) by groupnumber 1-3
- 90 trials per block
- targets (e.g. O vs. X) randomly determined (=> 1/2 the trials with 0)

* Trial Sequence:
- Fixation cross (250ms) -> white screen (random SOA duration) -> target 
(response terminated of maximum presentation of 1000ms)-> ITI (2000ms)
- SOA is randomly determined. By default in this script: frequency of SOAs fixed at 1/3 for each of the 3 SOAs 
(=> see list.soas)
- pairings of letter and sound the same for all: O and high tone vs. X and low tone

* Practice:
- 3 practice blocks of 20 trials each (order always: visual -> audio -> redundant)
- errorfeedback

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STIMULI
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* visual: X vs. O
* audio: low tone (125Hz) vs. high tone (1000Hz); provided sound files were generated in Audacity, 
length: 5s, Amplitude: 0.8
see section Editable Stimuli

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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).
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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:

Appearance of visual target:
/fontheight:								size of font (percentage of screen height) (default: 15%)

Appearance of audio target:
/volume_hightone:							volume adjustment for the high tone (default: -2000)
/volume_lowtone:							volume adjustment for the low tone (default: 0)


Durations:
/getReadyDuration:							duration (in ms) of get-ready trial (default: 5000ms)
/fixationcrossduration:						duration of fixation cross in ms (default: 250ms)

/maxtargetduration:							max duration that target is on screen in ms (default: 1000ms)
											Note: if no response is given, trial expires after presenting the target for parameters.maxtargetduration
											
/iti:										intertrialinterval in ms (default: 2000ms)

Responsekeys
/responsekey_left:								responsekey 1 (default: "A"), left response key
/responsekey_right:								responsekey 2 (default: "L"), right response key


/minRT:										minimum acceptable response latency in ms (default: 100ms)
/maxRT:										maximum acceptable response latency in ms (default: 1000ms)
											Note: outside these boundaries, the responses are counted as invalid trials