ABSTRACT
Ungerleider and Mishkin (1982), studying the visual cortex of monkeys, have shown that it is possible to distinguish between two cortical visual pathways; one involved in analysing where an object is and the other in recognising the object and understanding what it is. These two neural pathways are connected with object vision and spatial processing. From an anatomical point of view, both pathways originate in the primary visual cortex, diverging at the prestriate cortex and then proceeding ventrally through the inferior temporal cortex, or dorsally through the inferior parietal cortex, respectively. It is important to consider that these two circuits are both necessary for visual elaboration of a scene, although they convey different information. The ventral pathway conveys object information and the dorsal pathway spatial information. Subsequent research based on this distinction has confirmed Ungerleider and Mishkin’s early results, and has also suggested that a similar organisation could be present in humans (Haxby et al., 1991; Ungerleider & Haxby, 1994), not only in the case of visual perception but also when analysing higher processes such as mental imagery or VSWM (Courtney, Ungerleider, Keil, & Haxby, 1996). This idea is entirely consistent with a theoretical framework that assumes the equivalence of perception and imagery and, more generally, with the underlying assumption that mental imagery could be a synonym for high-level vision.
