Investigation of Certainty in High-Level Decisions by Analyzing Behavioral Data

Certainty is one of the parameters of hierarchical decisions. In hierarchical decisions, decisions at different levels are generally accompanied by uncertainty. After decision-making, the response can be positive or negative feedback. The reason for the negative feedback is unclear. Humans try to resolve this ambiguity by evaluating their certainty, so calculations of hierarchical decisions based on certainty are debatable. The complexity of computation for these types of decisions has made it more important to use other types of information in addition to behavioral data. Since decision processes are mapped to eye responses, this study analyzes the pupil diameter, in addition to behavioral data in the context of hierarchical decisions. In this research, pupil diameter size has been used as a valuable source for predicting hierarchical decision certainty.

In a hierarchical experiment, the subjects were asked to repeat the direction of the displayed moving points (left or right) at the top or bottom of the screen (top/bottom of the environment), as well as their certainty relative to the selected points, simultaneously. Subjects received auditory positive feedback when they reported both the direction of moving points and the environment correctly. During the experiment, the subjects' eye data were recorded by an eye-tracker device.

In hierarchical decisions, high-level decisions depend on the subject's degree of certainty in low-level decisions, and changes in pupil diameter are significantly associated with certainty.

This study revealed that in high-level decisions, the average size of the pupil diameter predicts the certainty of decisions and reflects the subject's strategy in complex conditions.