Gamma band response during auditory information processing in schizophrenia
-
1
University of Szeged, Hungary
-
2
University of Technology and Economics, Hungary
Introduction: Abnormal processing of auditory stimuli is a well known deficit in schizophrenia. Decreased suppression of the P50 auditory evoked potential (AEP) reflects impaired gating of sensory stimuli, while reduction of the auditory P300 amplitude is regarded as the index of abnormal attention dependent context updating and decision making. Time-frequency analysis of both AEPs revealed that besides enhancement of oscillatory activity in low frequency bands, an increased activity in the gamma band can also be observed both in the mid-latency and late time intervals. Since gamma activity is partly considered as an index of functional connectivity, the abnormal gamma band response in schizophrenic patients reported by several studies might reflect the failure of adequate network binding between certain cortical areas and thus supports the disconnection hypothesis of the disease.
Aims: We aimed to investigate whether clinically stable schizophrenic patients show disturbed processing of auditory stimuli both at early, preattentive (P50) and late stages (P300). Moreover, we were interested if the anticipated AEP amplitude reductions in schizophrenia would be accompanied by alterations of evoked and induced gamma band response.
Methods: 24 DSM-IV schizophrenic patients and 24 matched healthy control subjects participated in the study. EEG was recorded with 19 scalp electrodes. P50 suppression scores and P300 amplitudes were measured in both groups. The frequency, latency and magnitude of early, evoked and late, induced gamma band activity were determined with continuous complex Morlet wavelet analysis in both recordings.
Results: In line with previous studies we found decreased P50 suppression and reduced P300 amplitudes in the schizophrenic group. Early evoked gamma band response during P50 suppression was decreased in both frequency and amplitude when it was compared to the control group. In the active oddball paradigm we observed a reduced early evoked and late induced gamma band response for target stimuli in the patient population.
Conclusions: The underlying neural mechanisms of sensory gating and the late processing of auditory stimuli are not fully understood. Both processes involve multiple brain regions, and it is possible that the alterations observed in schizophrenia are not merely the consequence of the dysfunction of these cortical areas per se, but rather the result of their abnormal communication. The decreased early and late gamma band response might be the neural correlate of such disconnection the exact mechanism of which and the relation to schizophrenia needs further investigations.
Conference:
10th International Conference on Cognitive Neuroscience, Bodrum, Türkiye, 1 Sep - 5 Sep, 2008.
Presentation Type:
Poster Presentation
Topic:
Neuropsychiatric Disorders
Citation:
Csifcsak
G,
Garab
E,
Szendi
I and
Janka
Z
(2008). Gamma band response during auditory information processing in schizophrenia.
Conference Abstract:
10th International Conference on Cognitive Neuroscience.
doi: 10.3389/conf.neuro.09.2009.01.400
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
17 Dec 2008;
Published Online:
17 Dec 2008.
*
Correspondence:
Gabor Csifcsak, University of Szeged, Szeged, Hungary, gaborcsifcsak@yahoo.co.uk