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SERIAL REACTION TIME TASK
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 03-24-2016
last updated: 01-19-2023 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 01-19-2023 Millisecond Software
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BACKGROUND INFO
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This script implements a sequenced serial reaction time task (with 4 different response buttons) based on
several publications and the help of Dr. Maarten Immink:
Nissen, M. J., & Bullemer, P. (1987). Attentional requirements of learning: Evidence from performance measures.
Cognitive Psychology, 19, 1–32.
Reed, J. & Johnson, Peder (1994). Assessing Implicit Learning With Indirect Tests: Determining What Is Learned About Sequence Structure.
Journal of Experimental Psychology: LMC, 20, 585-594.
Abrahamse, E.L & Verwey, W.B. (2008). Context dependent learning in the serial RT task.
Psychological Research, 72:397–404.
Millisecond Software thanks Dr. Maarten Immink for his collaboration and assistance with this script!
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TASK DESCRIPTION
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Participants are presented 4 gray boxes in 4 possible screen positions and have to press
a spatially corresponding response button as fast as possible once one of the boxes turns red.
The task is divided into a
1) familiarization phase, involving a randomized order of stimulus presentation (default: 36 trials),
2)
a) pre-transfer sequence learning phase during which the screen position of the red box order of the stimulus presentation
follows a predetermined (repeating) sequence (default: 12 blocks),
b) a transfer phase, involving a new predetermined (repeating) sequence (default: 1 block) and
c) a post-transfer phase, involving the re-introduction of the sequence (repeating) presented during learning (default: 1 block).
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DURATION
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the default set-up of the script takes appr. 1.5h 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: 'serialreactiontimetask_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.
phase: "familiarization","learning", "transfer", "post-transfer"
countTestBlocks: counts the number of test blocks (training + transfer) run
countLearningBlocks: counts number of pre-transfer training blocks run
countTransferBlocks: counts number of transfer blocks run
countpostTransferBlocks: counts number of post transfer training blocks run
countTestTrials: counts the test trials in a block (resets for each test block - does not count starter trials)
countSequenceReps: counts the number of sequence reps in a block (does not count starter trials)
index: helper variable to determine the next stim position
position: 1, 2, 3, or 4 => screen position of the stim (red box) from left to right
stim_x: the screen position of the stim (red box) in canvas width percentages
response: the participant's response (scancode of response button)
correct: the correctness of the response (1 = correct; 0 = incorrect)
latency: the response latencyreaction time (in ms); measured from onset of red box stimulus
(2) Summary data file: 'serialreactiontimetask_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)
Note: mean and median latencies are reported of correct responses only. Correct responses are correct responses
within the defined response window (default: 2000ms). Error Responses are either wrong responses within the response
window OR no responses (response window terminated).
propCorrect_overall: determines the overall proportion correct in learning, transfer and post-transfer trials
meanRT_overall: determines the overall mean latency (in ms) of correct responses in learning, transfer and post-transfer trials
meadianRT_overall: determines the overall median latency (in ms) of correct responses in learning, transfer and post-transfer trials
propCorrect_Familiarization1-
propCorrect_Familiarization3: the proportion correct in Familiarization Block 1 - 3 (separate for each block)
Note: if default number of Familiarization Blocks was increased, add corresponding values below
and edit blocks and summary data accordingly
propCorrect_Learning1-
propCorrect_Learning12: the proportion correct in Learning Block 1 - 12 (separate for each block)
Note: if default number of Learning Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
propCorrect_Transfer1: the proportion correct in Transfer Block 1
Note: if default number of Transfer Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
propCorrect_postTransfer1: the proportion correct in Post-Transfer Block 1
Note: if default number of Post-Transfer Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
meanRT_Familiarization-
meanRT_Familiarization3: mean reaction time (in ms) of correct responses in Familiarization Block 1-3 (separate for each block)
Note: if default number of Familiarization Blocks was increased,
add corresponding values below and edit blocks and summary data accordingly
meanRT_Learning1-
meanRT_Learning12: mean reaction time (in ms) of correct responses in Learning Block 1-12 (separate for each block)
Note: if default number of Learning Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
meanRT_Transfer1: mean reaction time (in ms) of correct responses in Transfer Block 1
Note: if default number of Transfer Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
meanRT_postTransfer1: mean reaction time (in ms) of correct responses in Post-Transfer Block 1
Note: if default number of Post-Transfer Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
medianRT_Familiarization-
medianRT_Familiarization3: median reaction time (in ms) of correct responses in Familiarization Block 1-3 (separate for each block)
Note: if default number of Familiarization Blocks was increased,
add corresponding values below and edit blocks and summary data accordingly
medianRT_Learning1-
medianRT_Learning12: median reaction time (in ms) of correct responses in Learning Block 1-12 (separate for each block)
Note: if default number of Learning Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
medianRT_Transfer1: median reaction time (in ms) of correct responses in Transfer Block 1
Note: if default number of Transfer Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
medianRT_postTransfer1: median reaction time (in ms) of correct responses in Post-Transfer Block 1
Note: if default number of Post-Transfer Blocks was increased,
add corresponding code under: section VALUES/BLOCKS/DATA
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EXPERIMENTAL SET-UP
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- 1 blocks of 36 Familiarization/Familiarization trials (number of blocks can be edited under Editable Parameters)
with error feedback
- digit order of stimulus presentation is randomly determined with the constraint that successive positions are
different (aka no immediate position repeats)
- break after each block - unless it's the last familiarization block
Learning and Transfer Phases:
- 12 Learning blocks of 120 learning trials each (12-item sequence repeated for 10 cycles)
- each Learning block runs 10 repetitions of the learning sequence (see list.learning under Editable Lists)
- break after each block (default: 30s; editable)
- 1 Transfer block of 120 learning trials using a slightly different sequence
- each transfer block runs the transfer sequence (see list.transfer under Editable Lists)
- break after each block (default: 30s; editable)
- 1 postTransfer block of 120 learning trials using the learning sequence
- each postTransfer block runs 10 repetitions of the learning sequence (see list.learning under Editable Lists)
- break after each block (default: 30s; editable) - unless it's the last
Each block starts with presentation of 4 gray boxes before presentation of the stimulus for the first trial in each block.
After a response, the next target is presented after a response-stimulus interval (default RSI is 50 ms;
this can be edited under Editable Parameters).
If error feedback is provided, feedback is provided immediately after the error response and is followed by the RSI.
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STIMULI
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4 gray boxes - size and screen location can be edited under Editable Parameters.
Note: Abrahamse & Verwey (2008), e.g., used a viewing distance of 50cm and the stimulus angle measured 2.3° × 2.0°
Position of targets (box turning red) can be edited under section Editable Lists
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INSTRUCTIONS
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are not original; edit under section Editable Instructions
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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:
Procedural Design:
/numberFamiliarizationBlocks: number of familiarization blocks to run (default: 1); setting it to 0 will skip this block
/numberOfFamiliarizationTrials: number of familiarization trials to run in a block (default: 36)
/numberLearningBlocks: sets the number of pre-transfer training blocks (default: 12)
Note: if default number is changed, summary variables might need to be edited (Go to section VALUES)
/numberTransferBlocks: sets the number of transfer blocks (default: 1)
Note: if default number is changed, summary variables might need to be edited (Go to section VALUES)
/numberpostTransferBlocks: sets the number of post-transfer training blocks (default: 1)
Note: if default number is changed, summary variables might need to be edited (Go to section VALUES)
/numberOfSequenceRepsPerBlock: sets the number of sequence repetitions in each training/transfer block (default: 10)
/runErrorFeedback: true = error feedback (incorrect & too slow) is presented during test trials
false = error feedback (incorrect & too slow) is not presented during test trials
Interface: 0% at the far left of canvas - 100% far right of canvas
/pos1_x: the first horizonal box position from the left in canvas width percentages
/pos2_x: the second horizonal box position from the left in canvas width percentages
/pos3_x: the third horizonal box position from the left in canvas width percentages
/pos4_x: the fourth horizonal box position from the left in canvas width percentages
/stimHeight: height of the boxes in canvas height percentages (default: 5%)
Response Keys (from left to right):
/responsekey1: the first response button ("V")
/responsekey2: the second response button ("B")
/responsekey3: the third response button ("N")
/responsekey4: the fourth response button ("M")
Duration Paramters (in ms):
/responseWindow: duration of response window (in ms) (default: 2000ms)
/RSI: Response Stimulus Interval in ms (interval between response and presentation of next stimulus) (default: 50ms)
/feedbackDuration: duration (in ms) of feedback (default: 2000ms)
/breakDuration: the duration of the breaks (in ms) in between test blocks (default: 30000)
