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

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

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

Answer: (A)

Optic radiations form two main streams from the lateral geniculate nucleus to the primary visual cortex in the occipital lobe. The fibers carrying information from the inferior part of the visual field travel via the superior radiations through the parietal lobe before reaching the visual cortex. They end at the lower bank of the calcarine sulcus. By contrast, the inferior radiations loop through the temporal lobe (Meyer’s loop) to reach the upper bank of the calcarine sulcus. So, the pathway that carries the superior radiations passes through the parietal lobe first. This organization helps explain certain visual field defects when different parts of the optic radiation are affected.