INTEGRATION OF PHYSICAL AND SEMANTIC INFORMATION IN OBJECT PROCESSING

Physiological studies report independent processing pathways for form and colour information. A more-complex picture on human subjects has p reviously been reported. A sequential matching task was used that was based on a physical property of an object and in which semantic relati ons between stimuli were manipulated. Performance was affected by sema ntic information when matching was based on a property of the form of an object (its orientation, shape, or size). Effects of semantic infor mation were eliminated when matching was based on the colour of a loca l part of an object but were found again when subjects matched picture s on the basis of the percentage of a colour integrated across the sha pe boundary. The results suggest independent selection mechanisms in v ision in which selection by local colour can be based on inhibition of the form-processing pathway whilst processing of the global configura tion of the form of an object activates automatically the identificati on process.