Return to the Timed Chase Test page
TIMED CHASE TEST
Script Author: Katja Borchert, Ph.D. (firstname.lastname@example.org) for Millisecond Software, LLC
last updated: 04-19-2017 by K.Borchert for Millisecond Software LLC
Copyright © 04-19-2017 Millisecond Software
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.
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.
DATA FILE INFORMATION:
The default data stored in the data files are:
(1) Raw data file: 'TimedChaseTest_raw*.iqdat' (a separate file for each participant)
build: Inquisit build
computer.platform: the platform the script was run on
date, time, subject, group: date and time script was run with the current subject/groupnumber
/phase: 1 = Untimed Chase; 2 = Timed Chase
blockcode, blocknum: the name and number of the current block
trialcode, trialnum: the name and number of the currently recorded trial
(Note: not all trials that are run might record data; by default data is collected unless /recorddata = false is set for a particular trial/block)
/lastcorrectcell: stores the number of the last correct cell
Note: squares are labelled 1-100 from left to right
/selectnewflag: 1 = a new flag position needs to be found for next trial; 0 = flag stays put
/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)
response: the participant's response
/selectedcell: stores the number of the selected cell (the cell to which participant selected to move)
correct: 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)
/count_moves: counts the number of moves that participant makes (number of selections; selecting the disc at the beginning is not counted) in a block
/count_correctmoves: counts the number of correct moves that a participant makes in a block
/count_correctionmoves: counts the number of times participant correctly selects the last correct cell in a block
/count_errors: 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)
/count_LE: counts the number of times a Legal Error is made (one incorrect selection) per block
/count_PE: counts the number of times a Perservative Error is made (two incorrect selections in a row) per block
/count_RE: 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)
script.startdate: date script was run
script.starttime: time script was started
script.subjectid: subject id number
script.groupid: group id number
script.elapsedtime: time it took to run script (in ms)
computer.platform: the platform the script was run on
/completed: 0 = script was not completed (prematurely aborted); 1 = script was completed (all conditions run)
/count_moves: counts the number of moves that participant makes (number of selections; selecting the disc at the beginning is not counted) in the timed block
/count_correctmoves: counts the number of correct moves that a participant makes in the timed block
/count_correctionmoves: counts the number of times participant correctly selects the last correct cell in the timed block
/count_errors: sums up the number of errors made in the timed block
/count_LE: counts the number of times a Legal Error is made (one incorrect selection) in the timed block
/count_PE: counts the number of times a Perservative Error is made (two incorrect selections in a row) in the timed block
/count_RE: counts the number of Rule breaking Errors (three or more consecutive selections) in the timed block
/CMS: calculates the number of correct moves made per second in timed chase block ~ a measure of low-demand visuomotor speed
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.
flag = blue disc
10x10 matrix, gray squares
are not original. They are provided as simple htm documents and can be edited directly in the htm files.
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