Blake Saurels¹ (), Derek Arnold; ¹The University of Queensland, ²The University of Queensland

The neural latencies of your sensory brain are not too severe – just tens of milliseconds. Nonetheless, some have suggested that your brain tries to compensate for these brief lags to help you interact with fast moving objects. They suggest this could work via predictive processes at both early (retinal motion extrapolation) and later (neural pre-play) stages in the visual hierarchy. We are interested in how predictable motion impacts perception, and relating these changes in perception to neural predictive processes. We have approached this in two ways. The first uses the ‘Twinkle-Goes’ illusion (Nakayama & Holcombe, 2021, Journal of Vision), an apparent perceptual extrapolation of moving objects that suddenly disappear against dynamically updating white noise. We have: 1) refined the temporal conditions that produce the illusion, 2) showed that it is not the result of a decision level bias, and 3) showed that it impacts motor planning. Our second approach uses a temporal order judgement task to determine how predictable motion changes when objects seem to appear. We adapted the design of an EEG experiment that produced neural pre-play activity via apparent motion (Blom et al., 2020, PNAS). By testing different locations along the motion path, we can partition out the impact of exogenous attention capture (related to ‘prior entry’ effects). We have found that people report seeing objects sooner when they are presented along the expected motion path. But, only for a brief window (50 ms) after the motion ends, and we have found the opposite for objects presented after this window. Our latest work looks at how these changes in perception are predicted by differences in neural pre-play activity within and across individuals, as measured by EEG, and what factors might moderate these relationships.