Some brain diseases, such as Alzheimer’s and Parkinson’s, can be traced to the degeneration and death of neurons in a brain that was originally healthy. But other disorders, such as autism and schizophrenia, do not appear to be caused by neural degeneration. Rather, they are thought to be developmental disorders, in which a brain fails to wire up normally in the first place. Many have hypothesized that autism and schizophrenia are associated with pathological patterns of neural connectivity, or “connectopathies”. Yet we have never before possessed technologies powerful enough to detect these hypothetical miswirings of the brain.

It is arguable that studying autism and schizophrenia without such technologies is like studying infectious diseases without the microscope. Seeing the microbes that cause disease is not by itself a cure, but it accelerates research toward one. Similarly, finding a neuropathology that is truly distinctive of autism or schizophrenia would not be a cure by itself, but would be an important step in the right direction.