Predicting EEG responses using MEG sources in superior temporal gyrus reveals source asynchrony in patients with schizophrenia.
OBJECTIVE
An integrated analysis using Electroencephalography (EEG) and magnetoencephalography (MEG) is introduced to study abnormalities in early cortical responses to auditory stimuli in schizophrenia.


METHODS
Auditory responses were recorded simultaneously using EEG and MEG from 20 patients with schizophrenia and 19 control subjects. Bilateral superior temporal gyrus (STG) sources and their time courses were obtained using MEG for the 30-100 ms post-stimulus interval. The MEG STG source time courses were used to predict the EEG signal at electrode Cz.


RESULTS
In control subjects, the STG sources predicted the EEG Cz recording very well (97% variance explained). In schizophrenia patients, the STG sources accounted for substantially (86%) and significantly (P<0.0002) less variance. After MEG-derived STG activity was removed from the EEG Cz signal, the residual signal was dominated by 40 Hz activity, an indication that the remaining variance in EEG is probably contributed by other brain generators, rather than by random noise.


CONCLUSIONS
Integrated MEG and EEG analysis can differentiate patients and controls, and suggests a basis for a well established abnormality in the cortical auditory response in schizophrenia, implicating a disorder of functional connectivity in the relationship between STG sources and other brain generators.
Center for Functional Brain Imaging, New Mexico VA Health Care System, Building 49 (114M), 1501 San Pedro Drive, SE, Albuquerque 87108, USA. mhuang@unm.edu
M X
MX
Huang
J C
JC
Edgar
R J
RJ
Thoma
F M
FM
Hanlon
S N
SN
Moses
R R
RR
Lee
K M
KM
Paulson
M P
MP
Weisend
J G
JG
Irwin
J R
JR
Bustillo
L E
LE
Adler
G A
GA
Miller
J M
JM
Canive
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D004569:Electroencephalography / Q000379:methods*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D005544:Forecasting; D006801:Humans; D016018:Least-Squares Analysis; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010361:Patients / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000503:physiopathology*; D013702:Temporal Lobe / Q000502:physiology*