Cognitive Load during Eye-typing

In this paper, we have measured cognitive load during an interactive eye-tracking task. Eye-typing was chosen as the task, because of its familiarity, ubiquitousness and ease. Experiments with 18 participants, where they memorized and eye-typed easy and difficult sentences over four days, were used to compare the difficulty levels of the tasks using subjective scores and eye-metrics like blink duration, frequency and interval and pupil dilation were explored, in addition to performance measures like typing speed, error rate and attended but not selected rate. Typing performance lowered with increased task difficulty, while blink frequency, duration and interval were higher for the difficult tasks. Pupil dilation indicated the memorization process, but did not demonstrate a difference between easy and difficult tasks.