Smaller right ear (left hemisphere) advantage for dichotic fused words in patients with schizophrenia

The purposes of this study were to compare right ear (left hemisphere) advantage for dichotic words in schizophrenia and depression and to assess its association with antipsychotic medication, symptom ratings, and gender.

Thirty-two schizophrenic patients and 65 patients with major depression were given the Fused Rhymed Words Test, a dichotic listening measure of hemispheric dominance for language.

An earlier finding of smaller left hemisphere advantage in schizophrenic patients was replicated. There was no significant change in ear advantage in a subgroup of the schizophrenic patients tested when they were taking neuroleptics and when they were not. The smaller left hemisphere advantage in the schizophrenic patients was not dependent on gender but was related to symptom ratings on the Positive and Negative Syndrome Scale.

The findings are consistent with a left hemisphere dysfunction in schizophrenia, which is associated with positive symptoms.