From the dorsal/ventral functional dissociation in the visual cortex to that of the MTL

Posted: March 22, 2010 at 10:55 am

For this project the major value of the functional distinction, as proposed by Mishkin, Ungerleider, and Macko (1983), between the ventral and dorsal streams of the visual system are:

  1. The ventral stream is specialized for object recognition.
  2. The dorsal stream is specialized for object location and context.
  3. Brodmann area 40 (BA40), which is correlated with dreams, is in an interesting location between dorsal and ventral streams.

The idea was that BA40 may integrate from both ventral and dorsal streams, allowing dreams to combine contexts with objects in surprising ways. Unfortunately many studies refute the claims that the dorsal visual stream is correlated with object contexts and locations, and that it actually deals with sensorimotor control in visually guided behaviour (Goodale and Westwood, 2004).

There is evidence that a functional dissociation occurs in the processing of scenes/contexts and objects, but in the ventral stream. The hippocampus is associated with the processing of contexts and locations, while the perirhinal cortex is associated with object recognition (Murray, Bussey & Saksida, 2007). The project will continue with two subsystems, one for objects, and the other for contexts and locations. These ideas have been integrated into the working document: dreaming-machine-perception-synthesis.html.