Figure 1.

Schematic of trial structure in Experiments 1 and 2. Panel A. In Experiments 1 and 2, participants were instructed to categorize the target image as ‘tool’ or ‘animal’ with the index or middle fingers of the right hand. Each trial began with a jittered fixation (450, 550, 650, or 750 ms). In Experiment 1, the prime was then presented to the left or right of fixation for 33 ms; in Experiment 2 (Panel B) the prime was presented in one of eight locations arranged around central fixation. A scrambled image was presented at the same time as the prime in the other possible prime location(s). Visual masks were then presented (duration = 117 ms) in the same location as the prime as well as the locations of the scrambled stimuli. The offset of the mask was immediately followed by the target, which was on the screen for 3 seconds or until a response was given. In the follow-up prime discrimination task, the targets were replaced with question marks, and participants were told to discriminate the prime image when the question mark was presented. The trial structure for the prime discrimination task was exactly the same as in the main experiment.