Exploitative and Exploratory Attention in a Four-Armed Bandit Task

When making decisions, we are often forced to choose between something safe we have chosen before, and something unknown to us that is inherently risky, but may provide a better long-term outcome. This problem is known as the Exploitation-Exploration (EE) Trade-Off. Most previous studies on the EE Trade-Off have relied on response data, leading to some ambiguity over whether uncertainty leads to true exploratory behavior, or whether the pattern of responding simply reflects a simpler ratio choice rule (such as the Generalized Matching Law (Baum, 1974; Herrnstein, 1961)). Here, we argue that the study of this issue can be enriched by measuring changes in attention (via eye-gaze), with the potential to disambiguate these two accounts. We find that when moving from certainty into uncertainty, the overall level of attention to stimuli in the task increases; a finding we argue is outside of the scope of ratio choice rules.