A Stimulus-Driven Approach to Object Identity and Location Processing in the Human Brain

The primate visual system is considered to be segregated into ventral and dorsal streams specialized for processing object identity and location, respectively. We reexamined the dorsal/ventral model using a stimulus-driven approach to object identity and location processing. While looking at repeated presentations of a standard object at a standard location, subjects monitored for any infrequent "oddball" changes in object identity, location, or identity and location (conjunction). While the identity and location oddballs preferentially activated ventral and dorsal brain regions respectively, each oddball type activated both pathways. Furthermore, all oddball types recruited the lateral temporal cortex and the temporo-parietal junction. These findings suggest that a strict dorsal/ventral dual-stream model does not fully account for the perception of novel objects in space.