2. A rare neuropsychological disorder, meaning it is a disorder between the nervous system and mental functions, or in this case between the brain and perception.
In this kind of disorder, the person affected by it cannot perceive motion. It may be caused by disruption to the cortical area in the middle temporal lobe.
It can also be caused as a side effect of certain antidepressant drugs, a result of damage by a stroke, or by certain brain surgeries.