Parallel Search for a Conjunction of Shape and Contrast Polarity
HOOFDGROEP MAATSCHAPPELIJKE TECHNOLOGIE TNO DELFT (NETHERLANDS)
Pagination or Media Count:
When a target object embedded in an array of other objects can be distinguished along a single feature dimension e.g., colour or shape, it can be detected in parallel. When a target object is defined by a conjunction of stimulus features, search has to be conducted serially, indicating that the visual system is incapable of conducting a parallel search over two stimulus dimensions simultaneously. Earlier research has shown that there are two exceptions to this finding. one dimension can be searched in parallel if the other dimension is stereoscopic depth Nakayama Silverman, 1986, or relative motion McLeod, Driver Crisp, 1988. We report a third exception if one dimension involves contrast polarity, another dimension shape can be searched in parallel. The neurophysiological implications are discussed.
- Anatomy and Physiology