High-Frequency Oscillations in Schizophrenia

Neural oscillations and their synchronization may represent a versatile signal to realize flexible communication within and between cortical areas. There is extensive evidence that cognitive functions depending on coordination of distributed neural responses are associated with synchronized oscillatory activity, suggesting a functional mechanism of neural oscillations in cortical networks. In addition to their role in normal brain functioning, there is increasing evidence that altered oscillatory activity may be associated with certain neuropsychiatric disorders, such as schizophrenia, that involve dysfunctional cognition and behavior. In the present paper, the focus is on the role of high-frequency oscillations for cortical computations through establishing correlations between the modulation of oscillations in the beta/gamma frequency range and specific cognitive processes during normal brain functioning and in schizophrenia. Specifically, it is suggested that in addition to oscillations in the low (30-60 Hz) gamma-band range, gamma-band oscillations > 60 Hz may have a crucial role for the understanding of cognitive dysfunctions in schizophrenia. Perspectives for future research will be discussed in relationship to methodological issues, the utility of neural oscillations as a biomarker and the neurodevelopmental hypothesis of schizophrenia.