THE AUDITORY EVOKED RESPONSE AS A DIAGNOSTIC AND PROGNOSTIC MEASURE IN SCHIZOPHRENIA

Schizophrenic and nonschizophrenic mental patients can be distinguished by differences in the correlation between pairs of averaged evoked responses (AER) to tones of 600 cps and to tones of 1,000 cps recorded from scalp electroencephalographs. This two-tone AER effect was predicted from Shakow's segmental set theory. Schizophrenics preoccupied with ordinarily disregarded details place more value on the physical difference between two tones when no symbolic significance has been assigned and the evoked responses are more dissimilar. Clinical improvement in the schizophrenic patients was associated with a shift in the two-tone AER toward values seen in nonschizophrenics. No such change was found in nonschizophrenic patients. The clinically improved schizophrenics also demonstrated an increased amplitude of evoked response. The use of the measure as a diagnostic and prognostic technique is discussed.