Philosophy, Psychology and Neuroscience
The angular expansion hypothesis of locomotor space perception
The conscious perception of locomotor space (or action space) seems to be greatly distorted (ground distances appear much shorter than they are; hills look much steeper than they are, etc.) yet perception provides the basis for excellent control of action. Could large and systematic distortions in perceived locomotor space be for the purpose of action control? As a rough analogy, note that perceptual sensitivity trumps perceptual accuracy in the control of action – or watchmakers wouldn’t use magnifying glasses. I will review a large body of evidence suggesting that many well-documented and systematic biases in the perception of locomotor space arise from an angular coding scheme that may provide more efficient motor specification and/or feedback sensitivity for the control of action. Two interesting characteristics of the theory are that (1) its development is based on parameter measurement rather than null-hypothesis testing, and (2) much of the data used in support of the theory was collected or replicated by other labs before the theory was proposed. The critical new empirical observation of the theory is that while angular variables, like egocentric direction, are fundamental to action control, they are grossly and systematically distorted in spatial perception. This observation is sufficient to explain a great deal of historical data. The critical new theoretical observation is that stable distortions of this sort may be quite useful for action.