Fluctuation Patterns of Autonomic Arousal Predict Mental Arithmetic Performance

Pupil dilation, an autonomic arousal response, can measure attention because pupil dilation positively correlates with attention. This study investigated the predictability of mental arithmetic performance from pupil dilation fluctuation patterns of 11 college students. Arithmetic problems consisted of basic addition and varied in difficulty. The mental arithmetic task was administered while recording pupil dilation at 60 Hz with an ISCAN eye tracker. A pupil diameter baseline was measured before problems. Patterns of pupil diameter change from the baseline over time were analyzed by difficulty and performance. A marginal effect of Difficulty, marginal effect of Performance, and significant effect of Time on Pupil Dilation change were observed. Both Time by Difficulty and Time by Performance interacted significantly. However, Difficulty and Performance did not interact. These findings support the conclusion that attention increased over time during mental arithmetic problems. Furthermore, attention over time increased more on difficult problems and on correct problems