Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 02, 2013
Last Modified: January 06, 2023 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
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).
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.
25 minutes
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).
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
• 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
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).
File Name: redundantsignaltask_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 |
| correctpropOverall | Proportion of correct responses (valid trials only) across all test trials |
| meanrtOverall | Mean latency (in ms) of correct responses (valid trials only) across all test trials |
| correctpropVisual | Proportion of correct responses (valid trials only) for visual-only trials |
| meanrtVisualonly | Mean latency (in ms) of correct responses (valid trials only) for visual-only trials |
| correctpropAudio | Proportion of correct responses (valid trials only) for audio-only trials |
| meanrtAudioonly | Mean latency (in ms) of correct responses (valid trials only) for audio-only trials |
| correctpropRedundant | Proportion of correct responses (valid trials only) for combined trials |
| meanrtRedundant | Mean latency (in ms) of correct responses (valid trials only) for combined trials |
| percentInvalid | Percent invalid test trials (latencies outside specified boundaries) |
File Name: redundantsignaltask_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 |
| 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) |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| fontHeight | Size of font (percentage of screen height) Appearance of audio target | 15% |
| volumeHightone | Volume adjustment for the high tone | -2000 |
| volumeLowtone | Volume adjustment for the low tone durations | 0 |
| getReadyDuration | Duration (in ms) of get-ready trial | 5000ms |
| fixationCrossDuration | Duration of fixation cross in ms | 250ms |
| maxTargetDuration | Max duration that target is on screen in ms if no response is given, trial expires after presenting the target for parameters.maxtargetduration | 1000ms |
| iti | Intertrialinterval in ms responseKeys | 2000ms |
| responseKeyLeft | Responsekey 1 , left response key | "A" |
| responseKeyRight | Responsekey 2 , right response key | "L" |
| minRT | Minimum acceptable response latency in ms | 100ms |
| maxRT | Maximum acceptable response latency in ms outside these boundaries, the responses are counted as invalid trials | 1000ms |