Differences between objects and nonobjects in visual extinction: A competition for attention

We used visual extinction as a method for investigating the influence of objects on selective visual attention. Two subjects demonstrating extinction following damage to right parietal cortex were tested in a simple detection task. The task required only that subjects detect the presence or absence of any item in the left and right visual fields. Both subjects showed an advantage for good objects in the impaired field. However, this advantage for goon objects held only in the presence of a simultaneous stimulus in the undamaged field. We suggest that objects are not simply easier to detect than nonobjects; instead, we argue that objects are stronger competitors for attentional selection.