Source localization of high-frequency oscillations reveals widespread reductions in gamma-band activity in schizophrenia patients

Grützner, C.^1,2,3, Wibral, M.², Kohler, A.^1,2, Singer, W.^1,2,4, Maurer, K.³, and Uhlhaas, P. J.^1,2,3
1MPI for Brain Research, Department of Neurophysiology, Frankfurt; ²Brain Imaging Center, J.W. Goethe University, Frankfurt; ³Laboratory for Neurophysiology und Neuroimaging, J.W. Goethe University, Frankfurt; ⁴Frankfurt Institute for Advanced Studies, J. W. Goethe University, Frankfurt

Recent evidence suggests that schizophrenia patients are characterized by reduced synchronous, oscillatory activity in the beta- and gamma-band range. However, it has not been investigated yet to what extent high-frequency oscillations (>60Hz) contribute to impaired neural synchronization. Secondly, little is known about the neural generators that underlie the impairments in neural synchrony. Here, we employed magnetoencephalography during perceptual organisation in a sample of chronic schizophrenia patients and a group of healthy controls. We found a pronounced reduction in high-frequency gamma-band activity (60-120Hz) over parieto-occipital sensors in schizophrenia patients. To identify the sources underlying this impairment, we used a beamforming technique and performed source localization in the frequency range of maximum power in the gamma band. The analysis in source space revealed reduced power in the right temporal lobe in schizophrenia patients, suggesting that dysfunctional processing this brain region might underlie the observed deficits in neural synchrony and perceptual organisation.

Symposium 7: Novel Source Localisation Approaches in MEG-Data: Basic and Clinical Applications
11.06.2009, 14:30-15:45
Seminarraum 11