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Kreyenmeier, Philipp

University of British Columbia

Adaptive behaviour in a highly dynamic and complex environment necessitates the ability to transform sensory input into motor output at different timescales. The goal of this dissertation was to probe the sensorimotor processes that underlie precise movement control in rich sensory environments. In four experimental studies, I studied different types of tracking eye movements in response to stimuli that mirror some of the complexities found in the natural environment (complex pattern motion, target acceleration, and audiovisual signals). In the first study, I investigated the dynamic motion integration processes that give rise to the coherent perception of 2D pattern motion. Comparing eye movements to observers’ perceptual experience revealed shared motion integration mechanisms that drive continuous tracking and motion perception (Chapter 2). Accurate sensing of complex motion signals is a fundamental ability that allows humans to interact with objects moving along complex trajectories. In Chapter 3, I investigated how observers track and manually intercept accelerating targets. Results showed that observers continuously monitor the changing target speed but fail to account for acceleration to predict and intercept targets. Natural interaction with moving visual objects typically involves multiple senses. In two studies, I demonstrated profound and rapid effects of audiovisual integration on goal-directed actions. I found that auditory and visual signals were weighted according to their uncertainty to guide interceptive movements (Chapter 4). Finally, presenting audiovisual distractors during continuous visual tracking revealed multisensory response enhancement of reflexive movement inhibition at short latencies of ~100 milliseconds (Chapter 5). These findings were obtained using eye movements as a continuous indicator of human sensorimotor integration, highlighting the use of eye movements as a model system to study adaptive sensorimotor behaviour in dynamic environments. I propose a model that describes how eye movements at different timescales are affected by the dynamic processing of complex visual and audiovisual signals. The present findings can be used to inform training protocols for interceptive sports athletes and to assess sensorimotor deficits in clinical populations.

Text

2024-02-29

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87489

Neuroscience

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/