[The biphasic response in ERA (author's transl)].

Investigations (1975) of dyslectic children showed a biphasic evoked response summation curve. Four groups with distinct latencies of the biphasic curves were found. All children were expertly trained during the following years. Check-ups showed a consistent improvement in dichotic test results. Children having a biphasic curve in the first showed this again in the second investigation. Dyslectic qualities can be overcome by expert teaching and logopaedic exercises. Similar investigations were carried out with children showing various kinds of speech handicaps and with old age patients (without pathological ear problems). It is still questionable if the biphasic appearance shows "competition" of right and left hemisphere or whether it is a true organic failure of the brain to transmit acustic information from each ear to the central hearing regions (i.e., dichotic tests).