Figure 1. The spatial localization paradigm and exposure tasks.

(A) The localization task. Stimuli could be presented from one of five locations, ranging from −13 to +13 degrees. On any given trial, subjects could be presented with only an auditory stimulus, only a visual stimulus, or both an auditory and visual stimulus. The white lines in the figure designate all of the different spatial combinations of the bisensory trials, and the white “+” symbol denotes the fixation cross. (B) The exposure task paradigm. This was interleaved with localization blocks in the post-test phase. Depicted above is the stimulus arrangement from experiments #2, #5, and #6 where auditory and visual stimuli were always presented from 39 degrees apart, and alternated positions with each correct detection of the brighter flash. In experiments #3 and #4, the auditory and visual stimuli always were presented from the same location (−19.5 or +19.5 degrees), and alternated together from one side to the other. In experiment #1, no exposure task was implemented, and subjects simply listened to music during blocks when the normal exposure task occurred in other experiments.