Multiple Object Tracking (Online, RG Study)

Platform: HTML · English · verified today

This is a task in the RobbinGobblin Study study. Click to know more.

Local data export available

This task saves data locally in your browser and offers a download at the end of the session. For production use, you will need your own server-side persistence.

Description

The online Multiple Object Tracking task of the Bavelier lab's visual-attention battery (the JoVE 'Methods to Test Visual Attention Online' lineage), as run in the RobbinGobblin study. Moving dots appear as faces: cued targets start as blue sad faces, then all faces become yellow happy faces and keep moving; finally all dots stop and one is queried, and the participant presses B (was cued/started blue) or Y (was always yellow). The main task is 3 blocks of 20 trials (60 trials) with breaks between blocks, preceded by a gated practice phase. The number of attended dots varies per trial according to a fixed order (trialorder.txt); dot setup and movement use a seeded RNG (seedrandom.js) so trials are reproducible from the saved seeds. Stimulus sizes are calibrated per participant with a credit-card/CD screen-calibration procedure (pixels-per-degree). Frame draws (numDrawCalls) are logged per trial to audit timing fidelity. The study's MOT score — proportion correct on trials with 3 or more attended dots — drove group allocation in the RobbinGobblin randomization. This is a verbatim client-side port of the corrected rg-study code: only the PHP session/database layer was replaced (URL parameters + calibration in localStorage, results downloaded as JSON).

Contact & Lab

Lab

Brain and Learning Lab

unige.ch

Principal investigator

Daphné Bavelier

University of Geneva

Task contact

daphne.bavelier@unige.ch

Contributors

Sylvie Chantal Denkinger

University of Geneva

Investigation

Methodology

Amanda Yung

University of Rochester

Software

Paul-Emile Joëssel

Software

Kenneth Rioja

University of Geneva

Software

Daphné Bavelier

University of Geneva

Supervision

Hugo Farajallah

University of Geneva

Software

Data Curation

Citation

Pylyshyn, Z. W., & Storm, R. W. (1988). Tracking multiple independent targets: Evidence for a parallel tracking mechanism. Spatial Vision, 3(3), 179–197.
Yung, A., Cardoso-Leite, P., Dale, G., Bavelier, D., & Green, C. S. (2015). Methods to test visual attention online. Journal of Visualized Experiments, (96), e52470. https://doi.org/10.3791/52470

Credits

Client-side port of the RG-study MOT (gitlab.unige.ch/bavelierlab/rg-study, online-visual-attention lineage), Brain and Learning Lab (UNIGE).

Domains

Attention

Working Memory

Part of suite:

RobbinGobblin Study

Target Population

Age Categories

young adults

middle age

Clinical Status

non-clinical

Additional Notes

Run online in the RobbinGobblin study with adult participants recruited via Qualtrics/Prolific; requires a screen-calibration step and an uninterrupted, fullscreened session.

Languages

English

Run under

Engine

HTML / JavaScript

Format

Online (browser)

Modalities

behavioral

Task Outputs

What it measures

Measure multiple-object tracking capacity (proportion correct by number of attended dots) with reproducible seeded trials.

Output formats

json

One JSON download per participant: main-task trial rows (semicolon-joined per field, as saved by the original) plus a practice-trials file.

Experimental design

Trial-based

60 trials

Within-subject: numAttendDots

Conditions

numAttendDots

— Number of cued dots to track per trial, following the fixed trialorder.txt sequence.

Key measures for analysis

Tracking accuracy per numAttendDots
MOT score (proportion correct on trials with ≥3 attended dots)

Recorded variables

Variable	Role	Type	Description	Unit
`trialStart`	metadata	number	Trial start timestamp	-
`numAttendDots`	independent	number	Number of cued dots on the trial	-
`probeTracked`	independent	number	Whether the queried dot was originally cued	-
`response`	dependent	number	Participant response (B/Y key)	-
`correct`	dependent	number	1 if correct	-
`rt`	dependent	number	Response time	ms
`targetSeed`	metadata	string	RNG seed for dot setup	-
`trialSeed`	metadata	string	RNG seed for dot movement	-
`numDrawCalls`	metadata	number	Frames drawn during the trial (timing audit)	-
`pxperdeg`	metadata	number	Pixels per degree from calibration	-

Administration

Duration: ≈ 15 min
Sessions: 1
Input: keyboard
mouse
Audio: no audio
Adaptivity: fixed
Pause / resume: No
Practice phase: Yes
Offline-capable: Yes
Sessions notes: Administered at pre-test and post-test in the RobbinGobblin study; each administration is a single sitting.