In research using eye tracking, it was found that gaze was a good indication of subsequent choice. The research suggests that orienting and preference for objects in general are intrinsically linked in a positive feedback loop leading to the conscious choice.

Shimojo, S., Simion, C., Shimojo, E., & Scheier, C. (2003). Gaze bias both reflects and influences preference. Nature Neuroscience, 6(12), 1317–1322.