Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com), Millisecond
Created: January 27, 2022
Last Modified: January 09, 2025 by K. Borchert (katjab@millisecond.com), Millisecond
Script Copyright © Millisecond Software, LLC
This script implements Millisecond's version of a computerized Mirror Tracing Task (e.g. Starch, 1910), a measure of hand eye coordination and novel motor learning. In general, mirror tracing tasks ask participants to trace various shapes while only being able to see its mirror image.
Researchers can select to run the task with an absolute screen size to ensure that distances stay the same across devices. The default setting is to use proportional sizing. Go to section Defaults for more information.
The setup of this script was inspired by the Mirror Tracing Task described by the Pittsburgh Stress Battery. It uses a square and a circle to trace. A five-pointed star can also be run by this script; however, pixel errors are not computed for this shape.
Borresen, C. R. (1973). Reward, Punishment and Reversal on a Mirror-Tracing Task. Perceptual and Motor Skills, 37(1), 199–202. https://doi.org/10.2466/pms.1973.37.1.199
Julius, M. S., & Adi-Japha, E. (2016). A Developmental Perspective in Learning the Mirror-Drawing Task. Frontiers in Human Neuroscience, 10, 83–83. https://doi.org/10.3389/fnhum.2016.00083
11 minutes
The screen is divided into a mirror part (on top) and a drawing canvas (on the bottom). Participants will be asked to trace a shape (square and/or circle) on the drawing canvas (bottom) but can only see their tracing trail on the mirror image of the shape (on the top). By default, each tracing trial lasts at most 45s (editable parameter) before it is timed out.
By default, this script runs 3 tracing stimuli (square, circle, 5-pointed star) in a blocked design
with 5 trials each. By default, the order of the stims is randomized but can be fixed via list.blockOrder.
Each trial lasts at most 45s (Editable Parameter) before it is timed out.
After the first block, participants get the chance to take a break (self-paced).
By default, participants receive optional performance feedback at script conclusion.
Check section 'Editable Parameters' for parameters that control
- tracing stimuli (circle/square/star) conditions to run
- trial numbers
- trial timeouts
- performance feedback settings
etc.
Note that currently the script does not provide errorPx for the 5-pointed star condition.
provided by Millisecond - can be edited under section 'Editable Instructions'.
File Name: tracingtaskSummary*.iqdat
| Name | Description |
|---|---|
| inquisit.version | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| 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 |
Parameter Settings |
|
| tracingMechanism | "finger" vs."mouse" |
| tracingHand | "dominant" vs. "nondominant" vs. "left" vs. "right" |
| runTracingCircle, | True (1) or false (0) |
| runTracingSquare | True (1) or false (0) |
| runTracingStar | True (1) or false (0) |
| tracingCircleDiameterMM | The diameter of the tracing circle in mm |
| tracingSquareHeightMM | The diameter of the tracing square in mm |
| trackWidthMM | The width of the tracks around the stimulus in mm (the area that is considered 'on track') |
| trialCounterCircle | The number of trials run in the circle conditions |
| countSuccessCircle | The number of successful trials run in the circle condition success = participant reached the goal area (was not timed out) |
| trialCounterSquare | The number of trials run in the square conditions |
| countSuccessSquare | The number of successful trials run in the square condition success = participant reached the goal area (was not timed out) |
Latency Data (For Successful Attempts Only) |
|
| meanRT | Mean tracing RT (in ms) across stim conditions |
| meanRTCircle | Mean tracing RT (in ms) for circle condition trial |
| meanRTSquare | Mean RT (in ms) for square condition trials |
Pixel Error Data (For Successful Attempts Only) |
|
| meanPixelError | Mean pixel errors across stim conditions |
| meanPixelErrorCircle | Mean pixel errors in circle condition |
| meanPctErrorCircle | Converted pixel errors into canvas height percentages |
| meanPixelErrorSquare | Mean pixel errors in square condition |
| meanPctErrorSquare | Converted pixel errors into canvas height percentages |
| meanPixelErrorStar | Mean pixel errors in star condition |
| meanPctErrorStar | Converted pixel errors back into canvas height percentages ( 11% is the max error pct reported for Star shapes) |
File Name: mirrortracingtask_raw*.iqdat
| Name | Description |
|---|---|
| build | Inquisit version number |
| computer.platform | Device platform: win | mac |ios | android |
| computer.touch | 0 = device has no touchscreen capabilities; 1 = device has touchscreen capabilities |
| computer.hasKeyboard | 0 = no external keyboard detected; 1 = external keyboard detected |
| date | Date the session was run |
| time | Time the session was run |
| subject | Participant ID |
| group | Group number |
| session | Session number |
Parameter Settings |
|
| tracingMechanism | "finger" vs. "mouse" |
| tracingHand | "dominant" vs. "nondominant" vs. "left" vs. "right" |
| runTracingCircle, | True (1) or false (0) |
| runTracingSquare | True (1) or false (0) |
| runTracingStar | True (1) or false (0) |
| tracingCircleDiameterMM | The diameter of the tracing circle in mm |
| tracingSquareHeightMM | The diameter of the tracing square in mm |
| trackWidthMM | The width of the tracks around the stimulus in mm (the area that is considered 'on track') |
Trial Performance Metrics |
|
| blockcode | The name the current block (built-in Inquisit variable) |
| blocknum | The number of the current block (built-in Inquisit variable) |
| trialcode | The name of the currently recorded trial (built-in Inquisit variable) |
| trialnum | The number of the currently recorded trial (built-in Inquisit variable) trialnum is a built-in Inquisit variable; it counts all trials run even those that do not store data to the data file. |
| blockCounter | Counts the number of blocks run per condition |
| tracingStimCondition | 1 = square; 2 = circle; 3 = 5-pointed star |
| trialCounter | Trial counter per block |
| success | In trial.tracingCircle_tracing_end/trial.tracingSquare_tracing_end 1 = participant reached goal area 0 = trial was timed out (or ended prematurely) |
| countSuccess | Counts the number of successfule trials per block |
| ontrack | 1 = the current mouse coordinates are on the track around the circle/square (includes the target zone) 0 = outside the track |
| errorPX | For coordinates 'ontrack' -> 0 if not on track: the number of pixels that finger/mouse is currently away from track negative values: the finger/mouse went inside the tracing stimulus ('inside error') positive values: the finger/mouse went outside the tracing stimulus ('outside error') CIRCLE condition 'inside error': the (negative) pixel difference btw. inner track radius (in px) and distance from mouse coordinates to circle center 'outside error': the (positive) pixel difference btw. outer track radius (in px) and distance from mouse coordinates to circle center => see expressions.TracingCircle_errorPX SQUARE condition 'inside error': script returns the minimum of 4 possible distances to the inner track ( 'benefit of a doubt' coding) 1. vertical distance to top inner track 2. vertical distance to bottom inner track 3. horizontal distance to left inner track 4. horizontal distance to right inner track 'outside error': script determines in which of 8 possible locations (relative to the tracing square) the coordinates fall into 1. directly above: returns the difference in y coordinates of the outer track and the mouse coordinates 2. directly below: returns the difference in y coordinates of the outer track and the mouse coordinates 3. directly left: returns the difference in x coordinates of the outer track and the mouse coordinates 4. directly left: returns the difference in x coordinates of the outer track and the mouse coordinates the remaining locations return the distance of the mouse coordinates to the nearest corner of the outer track => see expressions.TracingSquare_errorPX STAR condition error pixels reported are the converted canvas height percentage errors (see below) |
| errorXPX | The horizontal x mouse/finger coordinate at time of error (not computed for Star) |
| errorYPX | The vertical y mouse/finger coordinate at time of error (not computed for Star) |
| meanTrialErrorPX | The mean of all 'errorPX' values across the trial (measure only is based on absolute values => of interest is the absolute distance) in the current trial calculated at the end of each trial |
| errorPct | Square/Circle: converts 'errorPX' into canvas height percentages Star The script uses several helper Stars to locate the movement coordinates relative to the track. Error distance percentages are reported in pct canvas height percentages in increments of 1%. There are 10 outer helper stars and 10 inner helper stars. Distance positive errors: outer errors 1%-10% => the coordinates were found on one of the outer helper stars 11% = the coordinates were an outer error outside of the 10 helper stars (max outer distance reported) negative errors: inner errors -10% to -1% => the coordinates were found on one of the inner helper stars -11% = the coordinates were an inner error outside of the 10 helper stars (max inner distance reported) |
| meanTrialErrorPct | Converts 'meanTrialErrorPX' into canvas height percentages |
| onTargetZone | 1 = mouse/finger coordinates are currently on the Target Zone; 0 = otherwise |
| leftTargetZone | 1 = mouse/finger coordinates have moved on from initial touchdown on Target Zone; 0 = otherwise |
| reachedTargetZone | 1 = mouse/finger coordinates have reached Target Zone again after once leaving it; 0 = otherwise |
| propOnTrack | Proportion onTrack responses for the current trial looks at the proportion of onTrackMovements relative to all Movements (excludes movements on target zone) |
Latency |
|
| tracingRT | The cumulative tracing Response Time (in ms) |
Coordinate Measures |
|
| mouse.x | The x coordinate of the finger at the time of the currently measured response (in pixel) |
| mouse.y | The y coordinate of the finger at the time of the currently measured response (in pixel) |
| mirrorX | The mirrored x-coordinate (in pixel) |
| mirrorY | The mirrored y-coordinate (in pixel) |
| targetZoneCenterXPX | The horizontal x-pixel position of the target/start circle |
| targetZoneCenterYPX | The vertical y-pixel position of the target/start circle |
| targetZoneDiameterPX | The pixel diameter of the target/start circle |
Inquisit Built-In Variables |
|
| response | The response of participant Example 'mousemove' => mouse coordinate change was noted or the name of the stimulus that was touched |
| correct | Correctness of response |
| latency | Measured from: onset trial until recorded response |
The procedure can be adjusted by setting the following parameters.
| Name | Description | Default |
|---|---|---|
Color Parameter |
||
| canvasColor | Display color of the actively used portion of the screen (the 'canvas') if set to a color other than the screenColor, the active canvas appears 'anchored' on the screen regardless of monitor size | white |
| screenColor | Color of the screen not used by the canvas ('inactive screen') | black |
| defaultTextColor | Default color of text items presented on active canvas | black |
Sizing Parameter |
||
| tracingCircleDiameterPct | The diameter of the circle in canvas height percentage | 35% |
| tracingSquareHeightPct | The height of the TracingSquare in canvas height percentage | 35% |
| tracingStarHeightPct | The height of the TracingStar in canvas height percentage | 40% |
| trackWidthPct | The width of the tracing track in canvas height percentage | 1% |
| tracingLineWidthPct | The width of the tracing line (drawn by participant) in canvas height percentage | 1% |
| targetZoneDiameterPct | The diameter of the target (also start) zone in canvas height percentage | 5% |
Design |
||
| runTracingSquare | True: the square condition is run; false = the square condition is skipped | true |
| runTracingCircle | True: the circle condition is run; false = the circle condition is skipped | true |
| runTracingStar | True: the star condition is run; false = the star condition is skipped | true |
| trialsPerTracingStim | Number of trials per Tracing Stim block By default, participants run 5 trials per square/circle/star stim | 5 |
| tracingMechanism | "finger" vs. "mouse" if set to 'finger' => trials will repeat if fingers is lifted prematurely off the screen during the tracing trials | "mouse" |
| tracingHand | Choose from: "dominant", "non-dominant", "left", "right" | "dominant" |
| skipPerformanceFeedback | True: participants won't receive any performance feedback at the end false: participants will receive performance feedback at the end | false |
Timing Parameter |
||
| trialTimeoutMS | The maximum time (in ms) that each tracing trial lasts | 45000 |