Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 23, 2015
Last Modified: January 02, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements Millisecond's version of the Timed Chase Test (TCT) - a simple test of visuomotor processing speed.
Note the script runs with proportional sizing by default. Researchers can select to run the task with an absolute screen size to ensure that distances stay the same across devices. See section Defaults for more info.
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.
2 minutes
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.
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.
flag = blue disc
10x10 matrix, gray squares
Instructions are provided by Millisecond.
They can be edited under section Editable Instructions.
File Name: timedchasetest_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 |
| 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) |
| leCounter | Counts the number of times a Legal Error is made (one incorrect selection) per block |
| peCounter | Counts the number of times a Perservative Error is made (two incorrect selections in a row) per block |
| reCounter | 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 |
File Name: timedchasetest_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 |
| phase | 1 = Untimed Chase 2 = Timed Chase |
| selectNewFlag | 1 = a new flag position needs to be found for next trial 0 = flag stays put 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) |
| leCounter | Counts the number of times a Legal Error is made (one incorrect selection) per block |
| peCounter | Counts the number of times a Perservative Error is made (two incorrect selections in a row) per block |
| reCounter | Counts the number of Rule breaking Errors (three or more consecutive selections) per block |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
| durationTimedBlock | Duration (in ms) of the timed block | 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 | true |
Color Parameter |
||
| canvasColor | Display color of the actively used portion of the screen (the 'canvas') if set to a color other than the screenColor, you can distinguish the active canvas from the inactive portion of the screen | black |
| screenColor | Color of the screen not used by the canvas ('inactive screen') | black |
| defaultTextColor | Default color of text items | white |