Assessment of attention network efficiency in schizophrenic patients with positive and negative symptoms

The aim of the present study was to examine the anterior (Experiment 1) and posterior (Experiment 2) attention systems in schizophrenic patients with predominantly negative or positive symptoms, in order to evidence possible differences in symptomatology.

The schizophrenic sample was divided into two subgroups: negative(n=13) versus positive symptoms (n=10). The anterior and posterior attention systems in schizophrenic patients were assessed through two experiments: a dual-task paradigm evaluating executive functions, in particular planning and coordination,and a Simon task evaluating automatic shifting of visual attention.

Our study showed specific attention deficits in the presence of negative symptoms. These findings suggest that negative schizophrenics have a deficit that affects functioning of both anterior and posterior attention systems, whereas positive schizophrenics showed a selective deficit only for the posterior attention system, with a pattern that is in the opposite direction compared to that of negative schizophrenics.

Our results demonstrate that specific symptom dimensions or patterns are associated with specific cognitive impairments. Notably, negative schizophrenics exhibited clear abnormalities, whereas positive schizophrenics performed very similarly to healthy controls.