A spatial bias toward highly rewarded locations is associated with awareness.

Mounting evidence suggests that monetary reward induces an incidentally learned selection bias toward highly rewarded features. It remains controversial, however, whether learning of reward regularities has similar effects on spatial attention. Here we ask whether spatial biases toward highly rewarded locations are learned implicitly, or are instead associated with explicit knowledge of reward structure. Participants completed a hybrid search and choice task involving multiple targets among multiple distractors. Targets garnered varying magnitudes of reward, and participants were instructed to search for targets and guess and click on the 1 that they thought would yield the highest reward. Unbeknownst to participants, 1 side of the display offered higher reward than the other. We measured the spatial bias for targets on the high-reward side of the screen and probed explicit awareness via a multiquestion interview. Participants who were aware of the reward structure (N = 48) showed a selection bias for targets appearing on the high-reward side of the screen. Contrary to previous findings, unaware participants (N = 24) showed only a significant central bias, despite spending just as much time on the task. The strong association between explicit awareness and reward-driven spatial attention in this paradigm suggests that instead of directly affecting the attentional priority map, probabilistic spatial reward learning more frequently affects attention indirectly by modulating task goals.