This method rests on a 50 year long tradition of Psychophysiological experiments at the Dept of Psychiatry in Lund, Sweden. Our branch has focused on Psychoacoustics since 1983, and found significant aberrant functioning of auditory perceptual mechanisms in schizophrenia. Some of these are possible to assess by ABR (auditory brain-stem responses). The assessments may be used to support the diagnostic decision process by demonstrating a biological dysfunction typical for the disease.

ABR measurements of twenty-three paranoid schizophrenics and matched controls for age and sex were compared. Eleven patented complex auditory stimuli, which schizophrenics earlier have been shown to perceive incorrectly, were presented. The ABR-measuring technique has been specifically adapted for the purpose.

When subjects were presented with a standard complex stimulus and a high-pass filtered one, schizophrenics showed statistically significant aberrances for wave V of the latter in the ABR, corresponding to the activity of colliculus inferior of the brain-stem. Furthermore, there was a significant change of activity regarding the two sides of the brain-stem, indicating a change of perceptual (grouping) activity in them.

This finding is just one example within the SchizoDetect method, aimed at helping medical personnel to ascertain the diagnosis of schizophrenia. It shows that different complex sound stimuli are treated in specific ways by schizophrenic patients. Together with the results from the ten remaining stimuli and further details of the ABR-curves, a diagnostic validity well over 90% has been achieved up till now.