Pupillary activity
blinks, partial occlusion of the eyelids
Participants sat comfortably with their chin supported over a chinrest to minimize head movement, at approximately 56 cm away from a Lenovo 23.8-inch screen with 1920 × 1080 resolution and 60 Hz refresh rate. At a 1000 Hz sampling rate, monocular gaze tracking and pupil size of the left eye of every participant were recorded with an SR Research EyeLink 1000 Plus which has an average accuracy of 0.15 visual angle. From the raw pupil size signal, samples 75 ms before and after blinks, as identified by the eye tracker, were converted to missing data to remove artifacts caused by partial occlusion of the eyelids (In order to assess the possible confounding impact of the pupil foreshortening error (