120 Specialized Visual Areas

Complex computations relating to vision, those that eventually allow you to have a visual experience of the world, all happen in the cortex. The first stop in the cortex is at the primary visual cortex (also known as V1). Here, the “reconstruction” process begins in earnest—based on the contrast information arriving from the eyes, neurons will start computing information about color and simple lines, detecting various orientations and thicknesses. Small-scale motion signals are also computed (Hubel & Wiesel, 1962). The computation of motion and aspects like color are what give rise to the ventral and dorsal pathways of vision.

Visual-recognition areas are located along the ventral pathway of the brain and terminate around the temporal lobe (the What pathway). Information that is funneled through this pathway is focused on identifying what a specific object is. Identification relies on multiple brain structures. We’ll name just a few here:

• The fusiform face area specializes in identifying objects for which fine discriminations are required, like faces. A later section of this book is dedicated to FFA.
• Extrastriate and fusiform body areas help us recognize and anticipate the motions of human bodies (Amoruso et al, 2011).
• Superior temporal sulcus houses many specialized regions related to language and social processing, with a posterior section that is specialized for the recognition of biological motion (Herrington et al, 2011).
• There is even a brain region specialized in letter and word processing called with visual word form area.

Brain regions along the dorsal pathway, near the parietal lobe (Fig. 11.4.1), (also referred to as Where-and-How pathway) compute information about self-motion and object-motion, allowing you to interact with objects, navigate the environment, and avoid obstacles (Goodale and Milner, 1992).

References

Herrington, J. D., Nymberg, C. Schultz, R. T. (2011). Biological motion task performance predicts superior temporal sulcus activity. Brain and Cognition 77(3):372-381. doi.org/10.1016/j.bandc.2011.09.001.