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*ALTERNATING SERIAL REACTION TIME TASK (ASRT)*
with keyboard input
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 02-03-2017
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 an Alternating Serial Reaction Task (with 4 different response buttons) based on
Howard, D.V. & Howard, J.H. (2004). Implicit Sequence Learning: Effects of Level of Structure,
Adult Age, and Extended Practice. Psychology and Aging, 19, 79–92.
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TASK DESCRIPTION
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Participants are presented 4 gray boxes in 4 possible screen positions (1, 2, 3, 4 with 1 being the left most box)
and have to press a spatially corresponding response button as fast as possible once one of the boxes turns red.
The boxes turn red in semi-random fashion:
a basic repeating pattern sequence (Example: 1, 3, 2, 4) is interweaved with
a random sequence.
Sequence: 1(Pattern), Random, 3 (Pattern), Random, 2 (Pattern), Random, 4 (Pattern), Random, 1 (Pattern), Random....etc
The number of random trials in between pattern trials is determined by parameters.lag:
lag = 2 => each pattern trial is followed by 1 random trial (every other trial is a pattern trial)
lag = 3 => each pattern trial is followed by 2 random trials etc. (every third trial is a pattern trial)
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DURATION
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the default set-up of the script takes appr. 45 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: 'asrt_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.
sequence: pattern sequence run
(parameter) Lag: sets the lag between patter trials (default: 2)
lag1 = every trial is a pattern trial (p1, p2, p3, p4, p1....)
lag2 = every other trial is a pattern trial (p1, r, p2, r, p3, r, p4, r, p1....)
lag3 = every third trial is a pattern trial (p1, r, r, p2, r, r, p3, r, r, p4, r, r, p1....)
countTestBlocks: counts the number of test blocks run
countPatternTrials: counts the pattern trials in a block (resets for each test block)
countRandomTrials: counts the random trials in a block (resets for each test block; excludes the start trials before the pattern is started)
countSequenceReps: counts the number of pattern 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 red stim (red box) from left to right
(parameter) RSI: Response Stimulus Interval in ms (interval between correct response and presentation of next stimulus) (default: 120ms)
response: the FINAL trial response (scancodes of the -default- keys pressed)
32: D
33: F
36: J
37: K
Note: script saves the final and -by design- correct response
correct: the correctness of the INITIAL response (1 = correct; 0 = incorrect)
Note: only correct responses advance to the next trial
latency: the response latency/reaction time (in ms); measured from onset of red box stimulus
until the correct response was entered (error penalty included)
P = pattern trial
R = random trial
FeedbackACC: overall proportion correct (pattern and random trials)
FeedbackRT: overall (pattern and random trials) median response time of correct responses
list.accuracyP.mean: proportion correct pattern trials in the current block (including currently run trial)
list.latenciesP.median: median latency (in ms) of responding to pattern trials in the current block (including currently run trial)
list.accuracyR.mean: proportion correct random trials in the current block (including currently run trial)
list.latenciesR.median: median latency (in ms) of responding to random trials in the current block (including currently run trial)
(2) Summary data file: 'asrt_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)
sequence: pattern sequence run
(parameter) lag: sets the lag between patter trials (default: 2)
lag1 = every trial is a pattern trial (p1, p2, p3, p4, p1....)
lag2 = every other trial is a pattern trial (p1, r, p2, r, p3, r, p4, r, p1....)
lag3 = every third trial is a pattern trial (p1, r, r, p2, r, r, p3, r, r, p4, r, r, p1....)
countTestBlocks: Test Block Counter
Performance Data:
proportion correct measures the accuracy of the INITIAL response;
'latency correct' measures the response time until the correct response was made
P = pattern trial
R = random trial
ACC_P: the mean of all block proportion corrects for pattern trials
RT_P: the mean of all block median correct latencies (in ms) for pattern trials
ACC_R: the mean of all block proportion corrects for random trials (start trials excluded)
RT_R: the mean of all block median correct latencies (in ms) for random trials (start trials excluded)
and separately for each testblocks:
ACC1_P - ACC21_P: proportion correct for Pattern trials (block1-21)
RT1_P - RT21_P: median correct latency (in ms) for Pattern trials (block1-21)
ACC1_P - ACC21_R: proportion correct for Random trials (block1-21)
RT1_P - RT21_R: median correct latency (in ms) for Random trials (block1-21)
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EXPERIMENTAL SET-UP
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*21 ASRT blocks that run
- 10 random position start trials (excluded from analysis)
- number of pattern repetitions (default: 10) x length of pattern sequence (default: 4) = 40 pattern trials
- number of random patterns = (parameters.lag - 1) * number of pattern trials (by default, with lag= 2: 40 random trials)
Each block starts with the presentation of 4 gray boxes for 120ms before the first box turns red.
Incorrect responses are recorded but response needs to be corrected for trial to terminate.
After a correct response, the next target is presented after a response-stimulus interval (default RSI is 120 ms;
this can be edited under Editable Parameters).
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STIMULI
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4 gray boxes - size and screen location can be edited under Editable Parameters.
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:
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:
/lag: sets the lag between patter trials (default: 2)
lag1 = every trial is a pattern trial (p1, p2, p3, p4, p1....)
lag2 = every other trial is a pattern trial (p1, r, p2, r, p3, r, p4, r, p1....)
lag3 = every third trial is a pattern trial (p1, r, r, p2, r, r, p3, r, r, p4, r, r, p1....)
/nrBlocks: number of blocks run (default: 21)
Note: default script provides summary variables for 21 blocks; if more should be run
add necessary values to VALUES and update block.ASRT under section BLOCK accordingly
/maxPatternRepetitions: the maximum number of pattern repetitions per block (default: 10)
Interface:
/pos1_x: the first horizonal box position from the left in canvas width percentages (0% at the far left of canvas - 100% far right of canvas)
/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 ("D")
/responsekey2: the second response button ("F")
/responsekey3: the third response button ("J")
/responsekey4: the fourth response button ("K")
Duration Paramters (in ms):
/RSI: Response Stimulus Interval in ms (interval between correct response and presentation of next stimulus) (default: 120ms)
/breakDuration: the duration of the breaks (in ms) in between test blocks (default: 30000)
/readyDuration: duration (in ms) of getting ready trial (default: 5000ms)
