This report describes the use of the averaged auditory evoked response to explore a particular psychological theory of schizophrenia. Specifically, the differences in electroencephalographic responses evoked by two trivially different tones are used to assess degree of preoccupation with ordinarily disregarded details of existence.
When a stimulus is presented to a subject, an electrical potential change can be detected at the top of the head. This is illustrated in Fig 1.
At the top of the figure are averaged responses evoked by two physically different tones—a tone of 600 cycles and a tone of 1,000 cycles. Although the tones are physically different, the forms of the evoked responses are almost identical. Before this pair of evoked responses were recorded, the subject was told to ignore the tones. Later, the subject could not recall having made any particular distinction between the high