MEG resting-state oscillations and their relationship to clinical symptoms in schizophrenia

Abstract

Neuroimaging studies suggest that schizophrenia is characterized by disturbances in oscillatory activity, although at present it remains unclear whether these neural abnormalities are driven by dimensions of symptomatology. Examining different subgroups of patients based on their symptomatology is thus very informative in understanding the role of neural oscillation patterns in schizophrenia. In the present study we examined whether neural oscillations in the delta, theta, alpha, beta and gamma bands correlate with positive and negative symptoms in individuals with schizophrenia (SZ) during rest. Resting-state brain activity of 39 SZ and 25 neurotypical controls was recorded using magnetoencephalography. Patients were categorized based on the severity of their positive and negative symptoms. Spectral analyses of beamformer data revealed that patients high in positive symptoms showed widespread low alpha power, and alpha power was negatively correlated with positive symptoms. In contrast, patients high in negative symptoms showed greater beta power in left hemisphere regions than those low in negative symptoms, and beta power was positively correlated with negative symptoms. We further discuss these findings and suggest that different neural mechanisms may underlie positive and negative symptoms in schizophrenia.

Keywords: Alpha band; Beta band; MEG; Negative symptoms; Neural oscillations; Positive symptoms; Resting-state; Schizophrenia.

Fig. 1

Power level for alpha band (1A) and beta band (1B). Error bars show standard errors. Con – controls; LP – SZ with low positive symptoms; HP – SZ with high positive symptoms; LN – SZ with low negative symptoms; HN – SZ with high negative symptoms. * p < .017.

Fig. 2

Topoplots of alpha power (2A) for Con, LP, and HP; and of beta power (2B) for Con, LN, and HN. Colors represent power levels.

Fig. 3

Significant clusters in the alpha band (2A) and beta band (2B). Colors represent F-values. L – left hemisphere; R – right hemisphere.

Fig. 4

Topoplots of cluster-based regression analysis results for alpha band (4A) and beta band (4B). Colors represent t-values.