Study Questions: LGN & Visual Cortex

1. Briefly describe the primary visual pathway for an object presented to the left visual field of both eyes.

2. What is a retinotopic map? Describe its characteristic distortion seen in both LGN and striate cortex.

3. Distinguish between cells in the parvocellular and magnocellular layers of the LGN.

4. Briefly describe the response characteristics of the three kinds of cells in the primary visual cortex as characterized by Hubel and Wiesel (simple, complex and hypercomplex cells).

5. Name at least three differences between receptive field properties of LGN and cortical cells.

6. Describe a simple model how a "line detector" can be built up in the visual cortex beginning with the LGN input as the initial building blocks.

7. Describe the way in which cells with different receptive field locations, orientation preference, and ocular dominance are layed out on the surface of striate visual cortex.

8. Briefly describe the response characteristics of cells in the "blob" and "interblob" regions of V1, and their relations to the thin stripe, thick stripe and pale stripe regions of V2.

9. Discuss the evidence for parallel functional streams (or pathways) in visual processing (parvo versus magno, parietal versus temporal).