**Core Concept**
Formed visual hallucinations refer to complex visual perceptions that are not based on reality. These hallucinations can involve shapes, patterns, or even entire scenes. The underlying cause is often related to abnormalities in the brain's visual processing pathways.

**Why the Correct Answer is Right**
Formed visual hallucinations are typically associated with lesions in the temporal lobe, specifically the medial temporal lobe. This region is involved in the processing of complex visual information and the integration of visual data with other sensory inputs. A lesion in this area can disrupt normal visual processing, leading to the formation of complex hallucinations. The temporal lobe's close proximity to the hippocampus, a structure involved in memory formation, may also contribute to the development of formed visual hallucinations.

**Why Each Wrong Option is Incorrect**
**Option A:** A lesion in the occipital lobe would more likely result in simple or unformed visual hallucinations, such as flashes of light or shapes, rather than complex formed hallucinations.
**Option B:** A lesion in the parietal lobe is more commonly associated with spatial disorientation and difficulties with navigation, rather than formed visual hallucinations.
**Option C:** A lesion in the frontal lobe can result in a wide range of cognitive and behavioral deficits, but is less commonly associated with formed visual hallucinations.

**Clinical Pearl / High-Yield Fact**
When evaluating a patient with formed visual hallucinations, it is essential to consider the possibility of a temporal lobe lesion, particularly in the context of a patient with a history of seizures or other neurological disorders.

**Correct Answer:** C.