Processing Negativity Sub-components as Corelates of Focused Attention in Health and Psychiatric Disorders (Auditory ERP Study)

Processing negativity (PN) is the potential in the difference waves between directed attention and the absence of attention to stimuli, reflecting the effectiveness of selective attention, however, it has been little studied, especially in mental disorders. 62 men were examined: 22 with schizophrenia spectrum disorders, 22 with personality disorders and 18 mentally healthy volunteers. Auditory evoked potentials were recorded in the oddball paradigm in two conditions: active (pressing a button on a deviant stimulus) and ignore (watching a video). Difference waves of PN (“active”–“ignore” condition), MMN (“deviant”–“standard” stimuli) and P300 (averaged evoked potential to a deviant stimulus) were calculated. A pointwise t-test, rmANOVA, topographic mapping, and correlation analysis were conducted. Three subcomponents were identified in the PN difference wave: early negative (PN, 60–160 ms), positive (PP, 250–400 ms), and late negative (LN, 400–600 ms). Significant differences in PN amplitude were found between groups, with the highest amplitude observed in subjects with personality disorders. Altered PN topography was observed in subjects with schizophrenia spectrum disorders. The PP and P300 amplitudes in the active condition showed high correlations and overlapping topographies. No significant between-group differences were found for MMN and P300 parameters. PN proved to be a more sensitive marker of attentional deficits than well-studied components. Increased PN in personality disorders may reflect attentional hyperreactivity, while topographic changes in schizophrenia may reflect dysfunction of frontoparietal networks. PP is a similar context updating process to P3 that is activated even by standard stimuli in a directed attention condition. PN subcomponents have diagnostic potential for assessing impairments in selective attention in schizophrenia and personality disorders.