Gamma Frequency–Range Abnormalities to Auditory Stimulation in Schizophrenia

Open Access
Publisher Website
Google Scholar
Abstract
GAMMA-FREQUENCY band neural activity (30-50 Hz or broader, centered on 40 Hz) has been hypothesized to reflect the synchronization of neural assemblies involved in binding or integration of various features of an object within a single sensory modality, across modalities, and across time.1-9 For example, gamma synchronization may be involved in the perception of a complex object, such as a cat, which requires integration of many features, such as luminance, color, texture, contours, and position, which are analyzed by discrete neurons or neural systems in the brain.6 Although the precise mechanisms of gamma synchronization are unknown, there is evidence of participation of γ-aminobutyric acid (GABA)ergic interneuronal circuits.5,10 There is also considerable evidence suggestive of abnormalities in GABAergic circuitry in schizophrenia.11,12 Failure or abnormality in gamma synchronization could result in a variety of perceptual and cognitive abnormalities, including abnormal perceptions, aberrant semantic association, hallucinations, and discontinuities in thinking, that occur in schizophrenia. Clementz et al13 recently proposed that transient disturbances of gamma-band response contribute to poor P50 evoked potential auditory response suppression in schizophrenia.