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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: 02-28-2022 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 02-28-2022 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
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.
practice: 0 = test trials; 1 = practice trials;
soa: current SOA
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
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
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)
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)
correctprop_overall: proportion of correct responses (valid trials only) across all test trials
meanrt_overall: mean latency (in ms) of correct responses (valid trials only) across all test trials
correctprop_visual: proportion of correct responses (valid trials only) for visual-only trials
meanrt_visualonly: mean latency (in ms) of correct responses (valid trials only) for visual-only trials
correctprop_audio: proportion of correct responses (valid trials only) for audio-only trials
meanrt_audioonly: mean latency (in ms) of correct responses (valid trials only) for audio-only trials
correctprop_redundant: proportion of correct responses (valid trials only) for combined trials
meanrt_redundant: mean latency (in ms) of correct responses (valid trials only) for combined trials
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
