Mismatch negativity, social cognition, and functioning in schizophrenia patients

Abstract

Background: Cognition and social cognition have been found to influence functional outcome in schizophrenia patients. However, little is known about the underlying neural substrates that are associated with social cognition or daily functioning. Prior studies found associations between mismatch negativity (MMN), an event-related potential response indexing early auditory processing, and functioning in schizophrenia patients.

Methods: In this study, we examined MMN, social cognition (social perception and theory of mind), and four domains of functioning (work, independent living, social networks, and family networks) in 33 schizophrenia patients and 42 demographically comparable healthy control subjects.

Results: Schizophrenia patients exhibited reduced MMN activity at frontocentral electrode sites compared with healthy control subjects. Within the schizophrenia sample, greater MMN activity at frontocentral sites correlated with better work and independent living (but not social or family networks) and with better social perception.

Conclusions: These results suggest that MMN activity is more closely tied to some outcome domains (work and independent living) than others. Mismatch negativity has been previously shown to be associated with basic cognition and functional outcome in schizophrenia, but these findings are the first, to our knowledge, to show MMN associations with social cognition. These results are consistent with cascade models of information processing in which deficits in early perceptual processing have a downstream impact on higher order social cognition and community functioning.

Figure 1

Grand average MMN waveforms for schizophrenia patients (in red) and healthy controls (in blue). Scale bar can be seen in the legend and at electrode Fz for reference.

Figure 2

Topographical map of MMN activity for healthy controls (on the left) and schizophrenia patients (on the right). MMN activity can be clearly seen at fronto-central sites for both groups, though patients are showing much smaller MMN amplitudes compared to the controls. Scale ranges from +4.5 μV (hot colors) to −4.5 μV (cold colors).

Figure 3

Topographical representation of correlations between MMN activity, functioning scores and social cognition scores for schizophrenia patients. Activity is plotted as Pearson’s r scores, and range from +0.10 (cold colors) to −0.50 (hot colors).