1979, University of Colorado Medical Center, Denver, Colorado

In the 1970s, a young doctor named Robert Freedman began researching the causes of schizophrenia. He began with a new theory that people with the disorder might have problems with “sensory grating”—that is, they might have brain abnormalities that make it difficult to process the information their senses registered. As a result, some might feel assaulted by too many sounds or too much information and might become paranoid, reactive or delusional (180).

Freedman developed a test in which a subject listened to two clicks in rapid succession while an electrode monitored their brain activity; his hypothesis was that people without schizophrenia would respond less strongly to the second click because their brain wouldn’t interpret it as new information, whereas those with schizophrenia wouldn’t be able to filter in this way. When this proved true, Freedman became interested in tracing sensory gating problems to a particular gene, thus proving the genetic nature of the disease. To do this, Freedman realized that he’d need to focus on schizophrenic patients who were related to one another and therefore shared much of their genetic material.