Micah Johnson in Scientific American:
Charles Whitman lived a fairly unremarkable life until August 1, 1966, when he murdered 16 people including his wife and mother. What transformed this 25-year-old Eagle Scout and Marine into one of modern America’s first and deadliest school shooters? His autopsy suggests one troubling explanation: Charles Whitman had a brain tumor pressing on his amygdala, a region of the brain crucial for emotion and behavioral control.
Can murder really be a symptom of brain disease? And if our brains can be hijacked so easily, do we really have free will?
Neuroscientists are shedding new light on these questions by uncovering how brain lesions can lead to criminal behavior. A recent study contains the first systematic review of 17 known cases where criminal behavior was preceded by the onset of a brain lesion. Is there one brain region consistently involved in cases of criminal behavior? No—the researchers found that the lesions were widely distributed throughout different brain regions. However, all the lesions were part of the same functional network, located on different parts of a single circuit that normally allows neurons throughout the brain to cooperate with each other on specific cognitive tasks. In an era of increasing excitement about mapping the brain’s “connectome,” this finding fits with our growing understanding of complex brain functions as residing not in discrete brain regions, but in densely connected networks of neurons spread throughout different parts of the brain.