Ability to perceive shape and size is lost due to the lesion of
**Core Concept**
The ability to perceive shape and size is a complex function of the brain that involves the integration of visual information from multiple sources. This function is primarily mediated by the lateral occipital complex (LOC) in the ventral visual pathway, which is responsible for object recognition and size perception.
**Why the Correct Answer is Right**
The correct answer is related to the lesion of the lateral occipital complex (LOC), which is crucial for the perception of shape and size. The LOC is a region in the ventral visual pathway that is involved in the processing of object shape, size, and orientation. Lesions in this area can result in difficulties with object recognition, including the perception of shape and size. The LOC receives input from earlier visual areas, including V1 and V2, and sends output to higher-level areas involved in object recognition, such as the fusiform gyrus.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because lesions of the primary visual cortex (V1) primarily affect basic visual functions such as acuity and color vision, rather than shape and size perception.
**Option B:** This option is incorrect because lesions of the superior colliculus primarily affect eye movements and attention, rather than shape and size perception.
**Option C:** This option is incorrect because lesions of the medial occipital complex primarily affect the perception of motion and depth, rather than shape and size perception.
**Clinical Pearl / High-Yield Fact**
The lateral occipital complex (LOC) is a critical region for object recognition, and lesions in this area can result in difficulties with shape and size perception. This is a key area to remember when evaluating patients with visual agnosias or object recognition deficits.
**Correct Answer: C.**