Renell Rodrigues¹, Guang Yang, David Yu, Martha Munro, Adam Guastella, Frans Verstraten; ¹The University of Sydney

Do individuals with autism (ASD) tend to see the trees but not the forest? Research findings in local and global perceptual processing have been inconsistent. These atypical perceptual patterns become evident in experiments investigating motion detection using motion coherence thresholds. For example, if 10% of randomly positioned dots move coherently in one direction, neurotypical individuals indicate the global direction with ease, whereas participants with ASD find it challenging to indicate the global direction. One assumption is that the local dots interfere with the visibility of the moving dots. To investigate this, we used a motion adaptation paradigm with participants from a social research group who all reach clinical criteria for autism spectrum disorder (DSM-5). Participants fixated on a dot on a screen, while being presented with a moving random pixel array (4 cardinal directions). After 30 seconds of adaptation to the motion stimulus, participants indicated the perceived aftereffect duration by pushing the space bar. The test pattern after adaptation was either a stationary noise pattern (a stationary random pixel array) or a dynamic noise pattern (the same random pixel array where the dots were continuously refreshed). Our hypothesis was that the dynamic test pattern will interfere with the ability to perceive the aftereffect. It was predicted that the aftereffect duration would be short or even absent for the dynamic test pattern. The results indicate that ASD participants are indeed unable to visually perceive the dynamic motion aftereffect. The aftereffect on a static pattern was successfully perceived. The preliminary conclusion is that the local noise inhibits the perception of the global motion signal and that there is potential to use this as a clinical assessment tool.