Figure 1.

Typical experimental designs to measure the ventriloquism effect and aftereffect. Exemplarily, letters indicate unimodal auditory (A) trials and relative locations of auditory (A) and visual (V) stimuli in bimodal trials. In an actual experiment, absolute stimulus locations typically vary between trials. (A) Ventriloquism effect. Participants have to localize cross-modal stimuli with varying spatial discrepancies. Unisensory localization is assessed in an optional pretest block. Comparison of responses between equivalent left- and right-side discrepancies or between bimodal and unimodal stimuli reveal the size of the ventriloquism effect. (B) Immediate ventriloquism aftereffect. Intermixed presentation of bimodal and unimodal trials. Localization in unimodal trials is modulated by the cross-modal discrepancy in the directly preceding bimodal trial. (C) Cumulative ventriloquism aftereffect. Unisensory sound localization is measured before and after exposure to cross-modal stimuli with a consistent spatial discrepancy. (D) Design used in Bruns and Röder (2015) to measure the immediate and cumulative ventriloquism aftereffects concurrently. Tones of two different sound-frequencies (A₁ and A₂) are consistently paired with opposite directions of cross-modal spatial discrepancy. Differences in localization responses between unimodal trials preceded by audiovisual trials with leftward vs. rightward discrepancy reveal the immediate aftereffect, and differences between unisensory localization of A₁ vs. A₂ reveal the cumulative aftereffect (see text for details).