Abnormal EEG Responses to Photic Stimulation in Schizophrenic Patients

Jin, Yi; Potkin, Steven G.; Rice, Dan; Sramek, John J.; Costa, Jerome; Isenhart, Robert; Heh, Chris; Sandman, Curt A.

doi:10.1093/schbul/16.4.627

Cited by 42 publications

(26 citation statements)

References 24 publications

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“…Although it has been reported that schizophrenic patients show a reduction in EEG photic driving responses [25][26][27] as well as abnormal VEP patterns [28,29], there have been no studies specifically investigating EEG coherence during PS in these patients. The present study showed that the schizophrenic patients had significantly higher intrahemispheric coherence than the control subjects on EEGs recorded during PS at 5 and 15 Hz.…”

Section: Discussionmentioning

confidence: 99%

“…A recent histopathological study documented abnormal neuronal density in the primary visual cortex of schizophrenic patients [24]. In addition, it has been reported that schizophrenic patients show abnormalities in EEG driving responses to PS [25][26][27] as well as in pattern-reversal visual-evoked potentials (VEPs) [28,29]. It is assumed therefore that a coherence analysis of EEGs recorded during PS would provide a useful means to assess the cerebral functioning of schizophrenic patients.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Aberrant Functional Organization in Schizophrenia: Analysis of EEG Coherence during Rest and Photic Stimulation in Drug-Naive Patients

Wada

Nanbu²,

Kikuchi³

et al. 1998

Neuropsychobiology

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EEG coherence provides a measure of functional correlations between two EEG signals. The present study was conducted to examine intrahemispheric EEG coherence at rest and during photic stimulation (PS) in 18 drug-naive patients with paranoid schizophrenia and 30 control subjects. Compared with the controls, the schizophrenic patients had significantly higher intrahemispheric coherence of the resting EEG for the delta band, although no significant group differences were found for other frequency bands. EEG analysis during PS showed that the patients also had significantly higher EEG coherence over the left posterior regions. In this study, we also examined the changes in intrahemispheric coherence from rest to the stimulus condition (i.e., PS-related coherence reactivity); the patients were found to show significantly smaller changes, with significant group differences being also confined to the posterior regions in the left hemisphere. These findings provide evidence that schizophrenic patients have abnormal EEG coherence in both resting and stimulus conditions and suggest more diffuse, undifferentiated functional organization within hemispheres. In addition, diminished coherence reactivity suggests a failure of PS-related functional reorganization in schizophrenia.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Aberrant Functional Organization in Schizophrenia: Analysis of EEG Coherence during Rest and Photic Stimulation in Drug-Naive Patients

Wada

Nanbu²,

Kikuchi³

et al. 1998

Neuropsychobiology

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show abstract

“…Thus, light stimulation is commonly used in routine EEG examinations and has proven to be useful in investigating neurological disorders (Takahashi 1989). However, numerous studies have performed only spectral analysis of the EEG induced by photic stimuli (Rice et al 1989;Jin et al 1990). Nonlinear methods may be helpful in diagnosing pathological states of the brain.…”

Section: Discussionmentioning

confidence: 99%

Nonlinear dynamics of the EEG separated by independent component analysis after sound and light stimulation

Jin

Jeong

et al. 2002

Biological Cybernetics

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The electroencephalogram (EEG) is a multiscaled signal consisting of several time-series components each with different dominant frequency ranges and different origins. Nonlinear measures of the EEG reflect the complexity of the overall EEG, but not of each component in it. The aim of this study is to examine effect of the sound and light (SL) stimulation on the complexity of each component of the EEG. We used independent component analysis to obtain independent components of the EEG. The first positive Lyapunov exponent (L1) was estimated as a nonlinear measure of complexity. Twelve subjects were administered photic and auditory stimuli with a frequency of 10 Hz, which corresponded to the alpha frequency of the EEG, by a sound and light entrainment device. We compared the L1 values of the EEGs and their independent components between baseline and after the SL stimulation. We detected that the L1 values of the EEG decreased after the SL stimulation in all channels except C3 and F4, indicating that the complexity of the EEG decreased. We showed that alpha components increased in proportion but decreased in complexity after the SL stimulation. The beta independent components were found to decrease in proportion and complexity. These results suggest that decreased complexity of the EEG after the SL stimulation may be principally caused by decreased complexity and increased proportion of the alpha independent components. We showed also that theta components increased in complexity after the SL stimulation. We propose that nonlinear dynamical analysis combined with independent component analysis may be helpful in understanding the temporal characteristics of the EEG, which cannot be detected by conventional linear or nonlinear methods.

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“…Electrophysiological measurement of photic stimulation has found reduced "photic driving" in the power spectra of patients with schizophrenia (12). It is a question for further investigation whether subjects who show reduced photic driving in the EEG also show enhanced CBF activation.…”

Section: Discussionmentioning

confidence: 99%

PET study of greater visual activation in schizophrenia

Taylor

Tandon²,

Koeppe³

1997

AJP

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E lementary sensory processing in schizophrenia has not been well studied with functional neuroimaging techniques, in spite of behavioral evidence suggesting abnormal function in the first 500 msec of stimulus input (1, 2). Using functional magnetic resonance imaging (MRI), Renshaw et al. (3) found an enhanced hemodynamic response to visual stimulation in patients with schizophrenia. A follow-up study from their laboratory (4) suggested that this enhanced perfusion change could occur because of increased cerebral blood volume in the vasculature of the occipital cortex, which they observed by using dynamic susceptibility contrast MRI.To cross-validate the initial functional MRI finding, we studied a similar group of medicated patients with the [ 15 O]H 2 O positron emission tomography (PET) technique and a graded photic stimulus, which yields a "dose-response" relationship in the visual cortex between stimulation rate and blood flow (5). We also infused subjects with acetazolamide, which increases cerebral blood flow (CBF) by means of a nonneuronal mechanism (inhibition of carbonic anhydrase). We reasoned that if patients with schizophrenia have greater vascular volume, as suggested by Cohen et al. (4), then we would see a greater CBF increase during the acetazolamide infusion in patients with schizophrenia than in normal comparison subjects. METHODWe recruited 11 stable patients with schizophrenia. Four were inpatients who were to be discharged, and seven were outpatients. Four were women. The patients' diagnoses were established by structured interview (6) and were based on DSM-IV criteria. All of the patients were taking psychotropic medications (nine were taking clozapine). Their mean age was 36.1 years (SD=7.5), and their mean duration of illness was 13.4 years (SD=6.8). Ten comparison subjects were matched to the patients in age (mean=35.8 years, SD=6.2) and sex (four of the comparison subjects were women). The comparison subjects had no history of psychiatric illness, according to structured interview (6), and none reported any first-degree relatives with an axis I psychiatric disorder. After a complete description of the study, written informed consent was obtained from all subjects.Subjects wore light-tight goggles that delivered a flashing visual stimulus by means of inset LED arrays at rates of 1, 3, 8, and 30 Hz. Subjects received a total of six scans; the four stimulation conditions and the one "null" condition (goggles on, no stimulus) were pseudo-randomized in the first five scans. Fifteen minutes before the sixth scan (a null stimulus), subjects received an intravenous infusion of 1 g of acetazolamide. Subjects were instructed to keep their eyes open for all scans.PET scans were performed with a Siemens CTI 931/08-12 camera (CTI Inc, Knoxville, Tenn.). For each emission scan, subjects received an intravenous bolus injection of 66 mCi of [ 15 O]H 2 O. Data were collected in a single 60-second frame beginning 5 seconds after the arrival of radioactivity in the brain. In seven normal subjects and fi...

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Abnormal EEG Responses to Photic Stimulation in Schizophrenic Patients

Cited by 42 publications

References 24 publications

Aberrant Functional Organization in Schizophrenia: Analysis of EEG Coherence during Rest and Photic Stimulation in Drug-Naive Patients

Aberrant Functional Organization in Schizophrenia: Analysis of EEG Coherence during Rest and Photic Stimulation in Drug-Naive Patients

Nonlinear dynamics of the EEG separated by independent component analysis after sound and light stimulation

PET study of greater visual activation in schizophrenia

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