Through which lobe do inferior radiations travel before reaching the visual cortex?

• A. Temporal lobe
• B. Parietal lobe
• C. Occipital lobe
• D. Frontal lobe

Answer: (A)

Inferior optic radiations travel through the temporal lobe in a curved path known as Meyer's loop before reaching the primary visual cortex in the occipital lobe. This loop carries information from the superior visual field (because the inferior retinal fibers represent the upper part of the field) and arcs around the inferior horn of the lateral ventricle to enter the lower bank of the calcarine fissure. Clinically, a lesion in this temporal-pathway results in a contralateral superior quadrantanopia, the classic “pie in the sky.” The superior radiations, by contrast, go through the parietal lobe to the upper bank of calcarine fissure, while the occipital lobe is the destination for the visual cortex; the frontal lobe is not involved in this visual radiation route.