Functional brain asymmetry and attentional modulation in young and stabilised schizophrenic patients: a dichotic listening study

Impaired functional brain asymmetry has been shown in schizophrenic patients, in addition to attentional deficits related to this laterality impairment. However, it has usually been shown in older patients with frequent positive symptoms. This is a matter of concern because previous studies have suggested that such deficits interact with subgroup characteristics, especially positive symptom,; like hallucinations and age/duration of the illness. Thus, in this study, we tested a homogeneous group of young and stabilised schizophrenic patients. We used a verbal dichotic listening test with consonant-vowel syllables to study brain asymmetry and attentional modulation. Nineteen patients were compared with healthy subjects with the same age, handedness and gender distribution. All subjects were tested during a divided and two focused attention conditions. The patient and reference group showed the same performance pattern. This indicates that young and stabilised patients show normal functional brain asymmetry and normal ability to modulate attention. It is suggested that impairments in functional asymmetry and attentional modulation may follow a continuum related to symptomatology and age/duration of illness. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.