Normative Representation of Objects: Evidence for an Ecological Bias in Object Perception and Memory

An apple can be held in your hand if you are eating it, or be perceived in a fruit bowl from a few meters away. While the apple’s real-world size is constant, the visual angle it subtends in your visual field varies based on your distance to the apple. Given the range of visual angles that an object can subtend in the visual field, is there a visual angle that is preferred? The current experiments show evidence supporting the idea of a privileged visual size for object representation, termed the normative size. In Experiment 1, observers adjusted the visual size of objects on a monitor, selecting the subjectively ‘right’ size to see the object. Inter-observer selections were strikingly consistent, and showed a correlation between the size selected on the screen and the actual physical size of the objects in the real world. These size selections were taken as estimates of the normative size for each object. In Experiments 2 and 3, using a size memory task and a change detection task, we found evidence that both long-term and short-term memory for the visual size of objects is biased towards the normative size. Altogether the results support the claims that perception of objects is sensitive to a normative size and that object memory is biased toward this perceptual norm.