causes of complex visual hallucinations
Irritation of the primary visual cortex (Brodmann's area 17) causes simple elementary visual hallucinations, while irritation of the visual association cortices (Brodmann's areas 18 and 19) causes more complex visual hallucinations.
Tumors that lie along, or compress, the optic path may cause visual hallucinations. In one case series, 13 of 59 patients with temporal lobe tumors experienced visual hallucinations. These hallucinations are described as complex and may involve vivid scenes (including people carrying out mundane tasks).