The larger than usual number of authors of this paper (listed, except for the first author, alphabetically) indicates that this research was a team effort in which three studies were conducted simultaneously by three teams of investigators. The effort began when Mark Lenzenweger conceived of the idea to study normally functioning college students who, on psychometric examination, showed significant elevations on traits that Loren and Jean Chapman have identified as schizotypal. Lenzenweger thought that it would be informative to determine how these students performed on tests that distinguish schizophrenic patients and their relatives from both the normal population and patients with nonschizophrenic illnesses. The scientists in our laboratory agreed.

Three teams of investigators set out from the Harvard-McLean Hospital laboratory to work at Cornell University, where they completed the testing of 57 people in Lenzenweger's population. Each of the teams completed a report of its own, which has been submitted for publication; these reports are summarized here. In addition, this chapter considers the performance of these college students on all of the tasks, which could not be done in the individual reports. The three tasks are (1) delayed response, from which we assess working memory; (2) antisaccade eye movements, and (3) thought disorder assessed from the Thought Disorder Index (TDI).

Rationale

The measures

For many years, the Psychology Research Laboratory at McLean Hospital has been studying psychological and psychophysiological characteristics that are associated with schizophrenia. Some of these performance measures show a familial aggregation among the relatives of schizophrenic individuals, which enhanced their significance beyond the mere demonstration that performance was deviant in a group of psychotic people.