Registered report: A multi-site replication of audiovisual cross-modal number adaptation

Just over ten years ago, Arrighi, Togoli, and Burr (2014) documented cross-modal effects of number adaptation: Observers adapting to pulses in the auditory modality experienced repulsive numerical aftereffects in the visual modality (and vice versa). They argued that these findings were indicative of "...a perceptual system that transcends vision and audition to encode an abstract sense of number in space and in time" (p. 1), and they have since become a cornerstone in the understanding of numerical perception and cognition. Recently, Yousif, Clarke, and Brannon (2024) have questioned these findings, citing their own failed replication as well as several theoretical inconsistencies. This report is an "adversarial collaboration" between those two parties. As part of this collaboration, data will be collected from 12 independent sites across three continents, in an effort to determine once and for all whether cross-modal number adaptation effects are genuine.