Return to the Timed Chase Test page
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TIMED CHASE TEST
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 10-23-2015
last updated: 09-22-2021 by K. Borchert (katjab@millisecond.com) for Millisecond Software, LLC
Script Copyright © 09-22-2021 Millisecond Software
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BACKGROUND INFO
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This script implements the Timed Chase Test (TCT) -a simple test of visuomotor processing speed- as described in:
Schroder, M.D, Snyder, P.J, Sielski, I. & Mayes, L. (2004). Impaired performance of children exposed in utero to cocaine
on a novel test of visuospatial working memory. Brain and Cognition, 55, 409–412.
Pietrzak, R. H., Cohen, H., & Snyder, P. J. (2007). Learning efficiency and error monitoring in normal aging:
An investigation using a novel hidden maze learning test. Archives of Clinical Neuropsychology, 22, 235–245.
Mathewson, K.J., Dywan, J., Snyder, P.J., Tays, W.J., & Segalowitz, S.J.(2008). Aging and electrocortical response
to error feedback during a spatial learning task. Psychophysiology, 45, 936–948.
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TASK DESCRIPTION
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Participants are asked to capture a flag represented by a blue disc that jumps through the squares of a
10x10 matrix. Once participants capture the flag, the flag jumps to a new location that is never more
than 2 squares away from the old location. Participants can only follow square by square in a horizontal
and vertical fashion; they cannot skip any square. If they make a mistake, they are directed to return
to the last correct square.
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DURATION
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the default set-up of the script takes appr. XXX minutes to complete
(if no task duration is provided, please contact Millisecond Software
(katjab@millisecond.com)
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DATA FILE INFORMATION
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The default data stored in the data files are:
(1) Raw data file: 'timedchasetest_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: 1 = Untimed Chase;
2 = Timed Chase
selectnewflag: 1 = a new flag position needs to be found for next trial;
0 = flag stays put
Note: squares are labelled 1-100 from left to right
previousFlagCell: stores the number of the square the flag was previously on
FlagCell: stores the number of the cell that contains the current flag
absoluteDiff: contains the absolute difference in box number between the previous and the current flag (for debug purposes)
lastCorrectCell: stores the number of the last correct cell
Response: the participant's response
selectedCell: stores the number of the selected cell (the cell to which participant selected to move)
ACC the correctness of the response (1 = correct; 0 = incorrect)
ErrorType: LE = Legal Error (one/first incorrect selection)
PE = Perserverance Error (second incorrect selection in a row)
RE = Rule break Error (third and more incorrect selections in a row)
Latency: the response latency (in ms)
movesCounter: counts the number of moves that participant makes (number of selections; selecting the disc at the beginning is not counted) in a block
correctMovesCounter: counts the number of correct moves that a participant makes in a block
correctionMovesCounter: counts the number of times participant correctly selects the last correct cell in a block
errorCounter: sums up the number of errors made in a block
ConsecutiveErrors: contains the number of Consecutive Errors made (resets after a correct response is given)
LE Counter: counts the number of times a Legal Error is made (one incorrect selection) per block
PE Counter: counts the number of times a Perservative Error is made (two incorrect selections in a row) per block
RE Counter: counts the number of Rule breaking Errors (three or more consecutive selections) per block
(2) Summary data file: 'timedchasetest_summary*.iqdat' (a separate file for each participant)
Computer Platform: the platform the script was run on (win/mac/ios/android)
Date: date script was run
Time: time script was started
Subject ID: assigned subject id number
Group ID: assigned group id number
Session ID: assigned session id number
Script Duration: time it took to run script (in ms); measured from onset to offset of script
Script Completion: 0 = script was not completed (prematurely aborted);
1 = script was completed (all conditions run)
movesCounter: counts the number of moves that participant makes (number of selections; selecting the disc at the beginning is not counted) in a block
correctMovesCounter: counts the number of correct moves that a participant makes in a block
correctionMovesCounter: counts the number of times participant correctly selects the last correct cell in a block
errorCounter: sums up the number of errors made in a block
ConsecutiveErrors: contains the number of Consecutive Errors made (resets after a correct response is given)
LE Counter: counts the number of times a Legal Error is made (one incorrect selection) per block
PE Counter: counts the number of times a Perservative Error is made (two incorrect selections in a row) per block
RE Counter: counts the number of Rule breaking Errors (three or more consecutive selections) per block
CMS: calculates the number of correct moves made per second in timed chase block ~ a measure of low-demand visuomotor speed
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EXPERIMENTAL SET-UP
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2 Blocks:
1) Untimed Chase: Participants start the block by clicking on the blue disc that is presented in the top left square.
The disc then appears in a new location (never more than 2 squares/moves away). Locations are randomly determined.
Participants have to 'capture' the disc by following square by square (on the shortest possible route towards the flag);
only moves immediately up and down as well as right and left are allowed. If participants choose a correct square, the square
turns green (and a chirp is played) and participant can continue. If participants make a mistake, the square turns red
(and a different sound is played) and participants need to return to the last correct square.
After 3 incorrect moves, the only square that can be selected is the last correct
square which is indicated by a flashing"!". The block ends by clicking a button labeled "done" at the bottom.
2) Timed Chase: The timed blocks runs for a predetermined length of time (default: 30s). No 'done' button is
provided. Otherwise, the same rules apply as for the untimed block.
The number of correct moves is counted.
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STIMULI
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flag = blue disc
10x10 matrix, gray squares
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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:
/duration_timedblock: duration of the timed block in ms (default: 30000)
/showerrorreminder: true = a verbal reminder to return to the last correct square is presented once participants has selected 3 incorrect squares
false = no verbal reminder is presented