Which LGN layers are parvocellular?

• A. Layers 1 and 2
• B. Layer 4 only
• C. Layers 3 to 6
• D. All layers

Answer: (C)

Think about how the LGN divides visual information into separate channels. The LGN has six main output layers. The outer two layers are magnocellular, containing large cells that relay motion and coarse features. The inner four layers—layers 3 through 6—are parvocellular, made of smaller cells that carry high-resolution detail and color information (red-green color opponency) to cortex. This parvocellular stream originates from color-sensitive retinal ganglion cells and provides the fine spatial detail that helps with precise form and color perception. Intervening between these major layers are the koniocellular layers, which contribute to additional color processing but are not parvocellular. Therefore, the parvocellular layers are layers 3 through 6.