Formed visual hallucinations are seen in lesions of:
The lesions of temporal lobe can cause all types of hallucinations (auditory, visual, olfactory etc). Formed visual hallucinations are elaborate visual hallucinations (e.g a patient may repo seeing a tree with green leaves which has a parrot sitting and a man standing near it) . The presence of elaborate visual hallucinations should raise a strong doubt of an organic cause (i.e. a pathology of brain parenchyma), specifically a temporal lobe pathology.
Frontal lobe
Temporal lobe
Occipital lobe
Parietal lobe
Basics of Psychiatry