PT  - JOURNAL ARTICLE
AU  - Johannes Bill
AU  - Hrag Pailian
AU  - Samuel J Gershman
AU  - Jan Drugowitsch
TI  - Hierarchical structure is employed by humans during visual motion perception
AID  - 10.1101/758573
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 758573
4099  - http://biorxiv.org/content/early/2019/09/05/758573.short
4100  - http://biorxiv.org/content/early/2019/09/05/758573.full
AB  - In the real world, complex dynamic scenes often arise from the composition of simpler parts. The visual system exploits this structure by hierarchically decomposing dynamic scenes: when we see a person walking on a train or an animal running in a herd, we recognize the individual’s movement as nested within a reference frame that is itself moving. Despite its ubiquity, surprisingly little is understood about the computations underlying hierarchical motion perception. To address this gap, we develop a novel class of stimuli that grant tight control over statistical relations among object velocities in dynamic scenes. We first demonstrate that structured motion stimuli benefit human multiple object tracking performance. This performance advantage is well-explained by a Bayesian observer model that exploits hierarchical structure. A second experiment, using a motion prediction task, reinforced this conclusion and provided fine-grained information about how the visual system flexibly exploits motion structure.