Participants’ categorization accuracy, response time,
and eye movements were recorded in both phases of category learning.
Importantly, participants were unaware that halfway through the task the target category switched (e.g., from A to C),
with an extra-dimensional shift between category-relevant information.
If participants optimized attention to category-relevant information before the switch,
they should incur a cost of selective attention immediately after the category switch where previously relevant information becomes irrelevant
(cf. Hoffman & Rehder, 2010; Kruschke & Blair, 2000).