A method for estimating the time of initiating correct categorization in mouse-tracking

Mouse-tracking facilitates exploration of the mental processes underlying decision-making. As the cognitive system works to settle on a decision, response competition manifests in the motor movements of the hand, bringing the mouse relatively closer to one alternative versus the other. Many metrics provide insight into decision-making processes by indexing the shape or complexity of the mouse trajectory. Lacking, however, is a metric that estimates the point in time when a participant begins to correctly categorize a stimulus. We rectify this absence by introducing a metric we refer to as time of initiating correct categorization (TICC), which is the point in time when people began moving relatively closer to the selected target relative to the distractor. We briefly review existing approaches to measuring time in mouse-tracking before describing the TICC and demonstrating its utility in three data sets.