PVT-BA

An adaptive Psychomotor Vigilance Test that measures sustained attention and reaction time. A millisecond counter appears after a random delay; the participant taps the screen as quickly as possible. A Bayesian sequential algorithm classifies vigilance into HIGH, MEDIUM, or LOW, often terminating early once the posterior probability exceeds a decision threshold.

• Duration: ≤ 180 s (adaptive)
• Source: Basner, 2022 — custom implementation
• Launch URL: https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/

Example URL commands

# Plain launch (debug mode: results shown on-screen)
https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/

# Suppress the completion screen
https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/?show_end_screen=false

# With camera recording
https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/?webcam=1

# With eye tracking
https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/?webgazer=1

# Customized assessment parameters (values shown are the defaults)
https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/?max_duration_seconds=180&min_isi_ms=1000&max_isi_ms=4000

# Production: submit results to your server
https://andreifoldes.github.io/m2c2-assessments/assessments/pvt-ba/?token=<TOKEN>&callback_url=<CALLBACK_URL>

Session parameters

Handled by the launch wrapper (results submission and optional sensors), not by the assessment itself.

Parameter	Type	Default	Description
callback_url	string	—	URL to POST results to when the assessment ends.
embed	string	—	Set to 1 for embedded mode (e.g. an ESMira PWA iframe): on completion, results are posted to the parent window via postMessage instead of an HTTP callback.
light	string	—	Set to 1 or true to enable ambient light sensing (where the browser supports the AmbientLightSensor API). Participants see a consent prompt; lux readings are recorded during the task and exported at session end.
pid	string	—	Optional participant identifier. Echoed verbatim into the results: top-level pid next to token in the callback POST, inside data, and in the embed-mode postMessage. Useful when the callback endpoint does not mint per-participant tokens, or to link multi-session designs (e.g. FNAME-Pairs learning vs. delayed) from the URL alone.
show_end_screen	string	true	Set to false or 0 to suppress the green "Assessment Complete" screen after results are submitted. A Telegram WebView closes immediately instead of showing the confirmation.
token	string	—	Authentication token for results submission. When absent (along with callback_url), the assessment runs in debug mode and displays results on-screen instead of submitting them.
tutorial	string	true	Set to false or 0 to skip the tutorial screens (alias for the show_tutorial assessment parameter).
webcam	string	—	Set to 1 or true to enable optional camera recording. Participants see a consent prompt; if they accept, the front camera records and the video is saved locally to their device at session end.
webgazer	string	—	Set to 1 or true to enable browser-based eye tracking via WebGazer.js. Participants see a consent prompt, then a 5-point gaze calibration. Gaze coordinates are recorded throughout the task and exported as a CSV file at session end. Can be combined with webcam=1.

Assessment parameters

Parameters marked URL can be set as URL query parameters; the rest are fixed deployment defaults.

Parameter	Type	Default	URL	Description
max_duration_seconds	number	180	✅	Maximum test duration in seconds
min_isi_ms	number	1000	✅	Minimum inter-stimulus interval in ms
max_isi_ms	number	4000	✅	Maximum inter-stimulus interval in ms
lapse_threshold_ms	number	355	✅	Reaction time threshold for a lapse in ms
false_start_threshold_ms	number	100	✅	Reaction time threshold for a false start in ms
decision_threshold	number	0.99619	✅	Posterior probability threshold to stop the test
feedback_duration_ms	number	1000	✅	Duration of feedback display in ms
show_quit_button	boolean	false	—	Whether to show a quit button
show_tutorial	boolean	true	✅	Whether to show the multi-screen tutorial before the test
show_results	boolean	false	—	Whether to show the detailed results page with High/Medium/Low classification. When false, participants see a simple completion message.

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Generated from assessments/pvt-ba/pvt-ba.js and assessments/pvt-ba/index.js. Do not edit by hand.