[Efficiency of the attention networks and severity of positive and negative symptoms in schizophrenia]

To examine the characteristics of the event related potentials during the attention network test in patients with schizophrenia depending on the severity of positive and negative symptoms.

The study included 20 patients with schizophrenia, 10 of them with a predominance of positive symptoms and 10 patients with a predominance of negative symptoms. All patients were diagnosed with paranoid schizophrenia (F20.0). Attention function was assessed using the attention network test with parallel recording of evoked responses. Differences in the amplitude and latency of N100 potential when presented with different types of cues, as well as P300 potential when identifying a congruent and incongruent flanker were analyzed.

A comparative analysis of N100 potential for neutral cues and flankers showed significantly lower amplitude and longer latency in the group of patients with a predominance of negative symptoms (Cz channel).The amplitude of the evoked N100 response upon presentation of central and spatial cues was significantly higher in the group of patients with a predominance of positive symptoms. An analysis of P300 potential in Fz channel with congruent and incongruent flankers revealed no differences in the amplitude of both stimuli in the group of patients with a predominance of negative symptoms, while the amplitude of the evoked response to congruent and incongruent flankers was significantly higher in the group with a predominance of positive symptoms. In the group of patients with a predominance of positive symptoms, an inverse flanker response was established - P300 amplitude was significantly higher upon presentation of an incongruent flanker.

The specific characteristics of evoked responses describing the features of such systems of attention as vigilance, orientation and conflict resolution have been established.