Successful interactions within the environment are contingent upon the perceiver’s ability to perceive the maximum extent over which they can perform actions, commonly referred to as action boundaries. Individuals are extremely sensitive to their action boundaries, and the perceptual system can quickly and flexibly recalibrate to changes in the size of action boundaries in the event of physiological and/or environmental changes. However, action boundaries are learned over time from perceptual-motor feedback across different environmental and physiological contexts, the information upon which action boundaries are based must inherently be characterised by variability. As a result, the judgement of one’s action boundary is more likely based on probability distribution rather than an immutable, exact borderline. Hence, the question then arises as to where on that distribution do people decide that an action is possible.
This thesis, therefore, seeks to understand how the perceptual system accounts for overt perceptual-motor variability in motor performance and recalibrate to new action boundary following changes in one’s action capabilities. In 11 experimental studies, this thesis examined (1) how the perceptual system accounts for overt perceptual-motor variability in motor performance for different actions, and (2) whether the perceptual system employs different strategies to determine action boundary to accommodate demands arisen from the consequences and costs-benefits ratios of a particular action.
The findings of this thesis suggest that the point on the distribution that acts as the judged action boundary varies as a function of task. Specifically, the strategy in which the perceptual system employs to determine action boundary after experiencing overt perceptual-motor variability in motor performance is specific the action, and the consequences and/or cost-benefits ratios of the outcome of a particular action but not the context. By using different approaches for different actions on an ad hoc basis to determine action boundaries, the perceptual system would be able to maximise the efficiency of information processing in the event of perceptual motor uncertainties, while minimising the exposure to potentially dangerous situations and aversive consequences. These findings of this thesis have broader theoretical and practical implications for future research in affordance perception and perceptual-motor recalibration.