Abstract
Visual motion perception is a difficult process to study in isolation given the intrinsic connection to object perception. One frequently used method of studying motion perception is random dot kinematograms (RDK) where a plane of moving dots are presented in various proportions of coherent motion. Though valuable, the majority of studies using RDK lack the complexity of higher-order perception. In the current study, a novel approach to motion detection was used to determine how later perceptual processes, primarily depth cues, can influence early motion signals. Here, we demonstrate that the presentation of task irrelevant, three-dimensional rotating stimuli can strongly influence the perception of task-central ambiguous motion. Participants observed a rotating orb constructed of surface-coordinate dots and a surrounding polygon. Participants were tested on whether they perceived motion congruous to the orb versus the task-irrelevant polygon. On each trial participants indicated the direction of orb rotation as well as any changes in the direction of rotation over the course of the trial. After initial response, trials continued briefly while the polygon would update to its secondary direction. Any secondary responses were also collected. Trials were split by a blank perceptual refresh screen. Trials were balanced across multiple factors: number of dots (1, 10, 100, 1000), direction of orb rotation (left or right), direction of polygon rotation (left or right), secondary direction of polygon rotation (left or right). Critically, the perception was biased by the direction of the polygon despite the fact that it was irrelevant to the primary motion decision. This suggests that motion detection is directly influenced by later perceptual processes including depth cues.
Acknowledgement: NSF/EPSCoR grant #1632849