Which of the following is not a subdivision of Layer IV?

Which of the following is not a subdivision of Layer IV?

• A. IVA
• B. IVB
• C. IVC
• D. IVD

Answer: (D)

Layer IV in the primary visual cortex is the main recipient of thalamic input and is split into several distinct sublayers to reflect different inputs and processing you get there. The recognized subdivisions are IVA, IVB, IVCα, and IVCβ. IVCα and IVCβ mainly carry the primary LGN inputs—the magnocellular and parvocellular channels—providing the core thalamic drive. IVA and IVB are more superficial within Layer IV and participate in onward cortical processing, sending information to other layers and areas. There is no named subdivision called IVD in this scheme, so that term does not represent a subdivision of Layer IV.

Layer IV in the primary visual cortex is the main recipient of thalamic input and is split into several distinct sublayers to reflect different inputs and processing you get there. The recognized subdivisions are IVA, IVB, IVCα, and IVCβ. IVCα and IVCβ mainly carry the primary LGN inputs—the magnocellular and parvocellular channels—providing the core thalamic drive. IVA and IVB are more superficial within Layer IV and participate in onward cortical processing, sending information to other layers and areas. There is no named subdivision called IVD in this scheme, so that term does not represent a subdivision of Layer IV.