Does task relevance shape the 'shift to global' in ambiguous motion perception?

Abstract

5Perception can differ even when the stimulus information is the same. Previous studies have 6 demonstrated the importance of experience and relevance on visual perception. We examined the 7 influence of perceptual relevance in an auxiliary task on subsequent perception of an ambiguous 8 stimulus. Observers were presented with an ambiguous motion stimulus that could either be perceived 9 as rotating dot-pairs ('local') or pulsating geometrical figures ('global'). Prolonged perception of this 10 stimulus is characterized by a 'shift to global', but it remained unclear whether this process is due to 11 relevance of the global percept or mere exposure to the stimulus. During a learning phase over five 12 successive days, participants were divided into conditions determining the relevant percept in an 13 auxiliary task: local, global, or none (active exposure). In a pre-and post-test, individual points of 14 subjective equality between 'local' and 'global' percepts were measured. Results indicate that there is 15 indeed a 'shift to global'. Interestingly, auxiliary task relevance does not seem to modify this process. 16