Schizophrenia is a disabling disorder that is associated with specific inheritable neurobiologic deficits. These deficits can cause problems with memory, visual attention, information processing, and other aspects of daily living. Understanding the genetic components of these deficits in people with schizophrenia and their unaffected family members may help uncover the neurobiological basis, risk factors, and heritability of the disease. In addition, the information may serve to create more effective treatments and possibly a cure for the disease. This study will serve to provide information about the genetic basis of known inherited neurobiological deficits in people with schizophrenia. In turn, this may guide further studies on the genetics of schizophrenia.

Participants will attend 2 study visits, each of which will last approximately 4 hours. The first will include blood tests and diagnostic interviews of participating families to evaluate the presence of schizophrenic symptoms. The second study visit will entail four neurocognitive and neurophysiological tests. Participants will first have a pre-pulse inhibition test, which uses electrodes to measure eye blinking. Electrodes will also be placed on participants' head, ears, and around their eyes to measure brain waves. Next, participants will undergo an oculomotor test, during which they will wear glasses fitted with sensors that record eye movement. Participants will then be asked to repeat a list of words, letters, and numbers read by a researcher. Last, participants will undergo a computerized performance test requiring them to watch the computer screen and click a mouse whenever they see a number between 0 and 9. Each study visit will take approximately 4 hours.