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.