Egocentric and Exocentric Spatial Judgements of Visual Displacement

The role of changes in ego- and exocentric spatial relationships on perceptual judgements about visual displacement was investigated in this study. Subjects were asked to indicate whether a dot in a test stimulus was displaced compared to a dot in a reference stimulus. Subjects were given explicit instructions to report displacement relative to themselves (egocentric) or relative to a circle surrounding the dot (exocentric). Four types of test stimuli were used in which object-circle (exocentric) and object-observer (egocentric) relations were systematically varied. It was found that for test stimuli that reveal conflicting ego- and exocentric spatial information, subjects performed poorly in both instruction conditions. This suggests that ego- and exocentric representations cannot be used independently and are probably interconnected.