Analysis of the non-stationarity of neural activity during an auditory oddball task in schizophrenia.
The aim of this study was to characterize brain dynamics during an auditory oddball task. For this purpose, a measure of the non-stationarity of a given time-frequency representation (TFR) was applied to electroencephalographic (EEG) signals. EEG activity was acquired from 20 schizophrenic (SCH) patients and 20 healthy controls while they underwent a three-stimulus auditory oddball task. The Degree of Stationarity (DS), a measure of the non-stationarity of the TFR, was computed using the continuous wavelet transform. DS was calculated for both the baseline [-300 0] ms and active task [150 550] ms windows of a P300 auditory oddball task. Results showed a statistically significant increase (p<;0.05) in non-stationarity for controls during the cognitive task in the central region, while less widespread statistically significant differences were obtained for SCH patients, especially in the beta-2 and gamma bands. Our findings support the relevance of DS as a means to study cerebral processing in SCH. Furthermore, the lack of statistically significant changes in DS for SCH patients suggests an abnormal reorganization of neural dynamics during an oddball task.
P
P
Nunez
J
J
Poza
J
J
Gomez-Pilar
A
A
Bachiller
C
C
Gomez
A
A
Lubeiro
V
V
Molina
R
R
Hornero
D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D001307:Auditory Perception; D001921:Brain / Q000502:physiology / Q000503:physiopathology; D001931:Brain Mapping; D016022:Case-Control Studies; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D058067:Wavelet Analysis