Using pupil dilation to measure cognitive load during a spatial skills test

This paper explores how spatial skills and cognitive load interact for engineering students. Spatial skills allow a person to manipulate and rotate a three-dimensional object in their “mind's eye.” Studies have reported that spatial skills can be a reliable predictor of problem-solving success in engineers. Despite the comprehensive literature on spatial skills, the cognitive load experienced while solving spatial items among engineering students is not fully understood. Using an eye tracking device, this study explored how the cognitive load experienced by high spatial visualizers differs when compared to low spatial visualizers in solving spatial tasks. Pupil dilation was recorded as a measure of cognitive load via an eye-tracking device as studies have shown that cognitive load causes a task-evoked pupillary response. Previous studies have shown that there is a linear increase in pupil dilation as cognitive load increases. The current study was conducted in two phases. The first phase recruited 143 undergraduate engineering students from two large, public, R1 institutions. Participants completed three spatial tests in phase 1. Based on their performance on the spatial tests, 35 participants were purposefully selected for the second phase of testing. While the first phase was conducted over a web conference platform, participants came in person for the second phase so that they could wear an eye-tracking device while completing further tasks. The phase 2 tasks included tests in spatial and verbal analogy and solving six engineering mechanics problems with increasing levels of difficulty. Data related to gender, race, and ethnicity were collected to understand if there were differences by demographic group. The larger study aims to examine several factors, including cognitive load, for high and low spatial visualizers while solving the six mechanics problems. In this paper, analysis results from the spatial testing component of the phase 2 testing will be presented.