`saccade-calibrate`

Shows a sequence of targets, collects eye embeddings at each, and fits the regression that turns an eye appearance into a point on this participant's screen. No gaze estimate exists until this trial finishes. Thirteen points at the defaults takes about twenty seconds.


Package	`@saccadejs/plugin-calibrate`
Browser global	`jsPsychSaccadeCalibrate`
Trial type	`saccade-calibrate`
Requires	the extension and a running camera, so it comes after `saccade-preview`

timeline.push({ type: jsPsychSaccadeCalibrate });

Parameters

Parameter	Type	Default	Description
`calibration_points`	`[number, number][]`	13 points: 3 × 3 at 5/50/95% plus four at 27.5/72.5%	`[x, y]` pairs as a percentage of viewport width and height.
`calibration_mode`	`"view" \| "click"`	`"view"`	`"view"` captures automatically after the settle interval; `"click"` waits for the participant to click each point.
`repetitions_per_point`	`number`	`1`	How many times the whole sequence of points is repeated.
`randomize_calibration_order`	`boolean`	`false`	Shuffle the order on each repetition.
`time_to_saccade`	`number`	`1000`	Settle time in ms before capture starts. The ring shrinks onto the dot over this interval.
`time_per_point`	`number`	`500`	Capture time in ms at each point. The ring turns green.
`point_size`	`number`	`20`	Diameter of the dot in pixels. The ring is four times this size.
`lambda`	`number \| null`	`null`	Ridge penalty. `null` uses `lambdaFor(n)`: 3 for nine points or fewer, otherwise 1.
`clear_previous`	`boolean`	`true`	Discard calibration points collected earlier in the experiment before starting.

Data

Field	Type	Description
`calibration_points_px`	`[number, number][]`	The targets shown, in the order they appeared, in viewport pixels. The `calibration_points` parameter stays in percent.
`n_points`	`number`	The number of distinct targets used.
`repetitions_per_point`	`number`	How many times the sequence was repeated.
`lambda`	`number`	The ridge penalty the fit used, or `null` if the fit failed.
`rt`	`number`	Milliseconds from trial start to the end of calibration.

Example

// A denser grid, randomised, for a study that can afford the extra time.
timeline.push({
  type: jsPsychSaccadeCalibrate,
  calibration_points: [
    [10, 10], [30, 10], [50, 10], [70, 10], [90, 10],
    [10, 30], [30, 30], [50, 30], [70, 30], [90, 30],
    [10, 50], [30, 50], [50, 50], [70, 50], [90, 50],
    [10, 70], [30, 70], [50, 70], [70, 70], [90, 70],
    [10, 90], [30, 90], [50, 90], [70, 90], [90, 90],
  ],
  randomize_calibration_order: true,
  time_to_saccade: 1200,
  time_per_point: 600,
});

Ask participants to move their eyes rather than their head, and to hold the pose they will use for the rest of the experiment. Then validate.

Parameters​

Data​

Example​

Parameters

Data

Example