Fig 1.

Definition of spatial attention ROIs. (A) Trial design. Each block of trials began with a screen instructing the subjects which feature to attend. In each trial, two snowflake objects were presented, followed by a mask and a test object. Subjects determined whether the test matched one of the two sample objects in the attended feature (shape or location). Object colors were uninformative for the shape and location judgments and were used for pilot experiments of feature conjunctions (data not shown). (B) Brain activation for location (red) compared to shape judgment (blue). Location judgment activated two regions of the parietal cortex: anterior intra-parietal (green arrow) and superior parietal (BA7) cortex (purple arrow).