Egocentric and exocentric spatial judgements of visual displacement

The role of changes in ego- and exocentric spatial relationships on percept ual judgements about visual displacement was investigated in this study. Su bjects were asked to indicate whether a dot in a test stimulus was displace d compared to a dot in a reference stimulus. Subjects mere given explicit i nstructions to report displacement relative to themselves (egocentric) or r elative to a circle surrounding the dot (exocentric). Four types of test st imuli were used in which object-circle (exocentric) and object-observer (eg ocentric) relations were systematically varied. It was found that for test stimuli that reveal conflicting ego- and exocentric spatial information, su bjects performed poorly in both instruction conditions. This suggests that ego- and exocentric representations cannot be used independently and are pr obably interconnected.