Exploring gaze entropy as a novel measure of visual scanning efficiency in problem solving


Gaze behaviour (i.e., the pattern of fixations and eye movements) is task dependent and tightly linked to underlying perceptual, cognitive and motor processes. Most research to date has examined the association between gaze behaviour characteristics and subsequent goal-directed actions using relatively simple problem-solving paradigms that do not match the complexity of those used in clinical or real-world applications. Therefore, the present investigation sought to examine gaze behaviour during a standardized version of the Tower of London (TOL) task in healthy adults, which is typically used to assess planning and problem-solving capabilities in clinical populations. The current study applied a novel method of gaze analysis to examine if changes in gaze entropy (i.e., gaze dispersion and predictability) were associated with the increasing demands placed on planning and working memory. Participants completed the Freiburg version of the TOL task. Gaze was recorded across 28 trials of increasing task difficulty (i.e., number of moves required to complete task goal). Preliminary analysis of two participants demonstrated that as task difficulty increased, stationary gaze entropy (i.e., spatial dispersion) increased and decreased in the initial planning stage and solution execution stage, respectively. Furthermore, gaze transition entropy (i.e., scan path predictability) during the planning stage demonstrated an inverted U-shaped trend as task difficulty increased, while the execution stage displayed a noticeable decrease in gaze transition entropy. Preliminary evidence suggests that task difficulty is linked to distinct changes in the spatial dispersion and predictability of gaze patterns across the different stages of planning and problem-solving.