Time and frequency domain event-related electrical activity associated with response control in schizophrenia.
OBJECTIVE
To confirm previously reported abnormalities in time domain EEG components during a go/no-go task in schizophrenia, and to test the hypothesis that patients exhibit abnormalities in frequency domain components reflecting indices of behavioural impairment.


METHODS
EEG data were recorded from 17 male schizophrenia patients in a stable phase of illness and 17 healthy controls.


RESULTS
As compared with controls, patients displayed smaller N200 amplitudes and less evoked theta for correct hit trials; and smaller N200 and P300 amplitudes and less evoked delta and theta for correct reject trials. Effect sizes were largest for evoked delta. Source localisation revealed reduced activation in schizophrenia patients during the N200 and P300 time windows in anterior and posterior cingulate, medial frontal gyrus and precuneus. Evoked delta and theta oscillations were significantly correlated with the variability of reaction times and the performance level statistic d-prime.


CONCLUSIONS
The results demonstrate impairment of frontal and parietal brain areas involved in response control in schizophrenia. They also suggest that the timing of oscillations in patients is less precise leading to smaller evoked amplitudes and more variable reaction times.


CONCLUSIONS
These findings add to the evidence that abnormal EEG oscillations contribute to impaired behavioural control in schizophrenia.
Doege
Kathrin
K
Division of Psychiatry, School of Community Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK. mcxkd4@nottingham.ac.uk
Kumar
Mahendra
M
Bates
Alan Thomas
AT
Das
Debasis
D
Boks
Marco Paul Maria
MP
Liddle
Peter Francis
PF
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000473:pathology / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D013997:Time Factors; D055815:Young Adult