Biomedical subjects
E A Serafetinides
Publications and source records attributed to E A Serafetinides.
Lateralized attentional abnormality in schizophrenia is correlated with severity of symptoms.
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Cerebral laterality and consciousness.
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Transient epileptic amnesia--a clinical update and a reformulation.
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The N15 component of the brainstem auditory evoked potential: a measure of hippocampal activity in schizophrenics?
The negative wave component of the brainstem auditory evoked potential at approximately 15 ms has been found to be related to activity in the hippocampus. Since hippocampal abnormalities have been reported among schizophrenic patients, it is obvious that a reliable electrophysiological measure of hippocampal activity might be useful in the study of schizophrenia. For instance, it may be hypothesized that the N15 wave of the BAEP would be abnormally reduced in amplitude for schizophrenics compared to controls, based on the previously reported misalignment of neurons in the hippocampus for schizophrenics. The measurement of the N15 is complicated by the presence of a postauricular muscle reflex in some individuals. We attempted an analysis of the N15 wave based on distributional characteristics for schizophrenics and control subjects. The nature of the N15 wave is described and potential lines of investigation are proposed.
Age, alcoholism and depression are associated with low levels of urinary melatonin.
Two normal control populations, separated by 8,000 miles and 24 degrees of latitude, had similar six-month mean values for overnight urinary melatonin concentrations. These values were significantly higher than six-month values for depressed subjects and abstinent alcoholic subjects, while the means for the two clinical populations were similar. Age and urinary melatonin concentration in the control and clinical populations were inversely related, but the slopes of the linear regression equations were ten times steeper for the control populations than for the clinical populations. Differences in age and sex distributions accounted for some of the differences in values between controls and the clinical populations, although controls still differed from the clinical populations, even after sex and age were factored out. The disparate slopes for age and melatonin concentrations may contribute to some of the conflicting findings of studies comparing populations of different ages. The total melatonin content in the samples from alcoholic subjects, but not the depressed subjects, was lower than that for controls. The difference in the urinary melatonin concentration between the controls and the two patient groups was not accounted for by difference in duration of urine collection period, hours of sleep or body weight.
Cost of psychiatric illness versus cost of psychiatric research.
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Comparison of eye movement patterns of dreaming and arousal in sleep.
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Cerebral dominance and sleep: a comparison according to handedness and time of sleep.
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Schizophrenia, corpus callosum, and interhemispheric communication: a review.
The literature suggests that some schizophrenic patients may have a dysfunction in the transfer of information between the two cerebral hemispheres via the corpus callosum (CC). The presence of an abnormally thickened CC in some schizophrenic patients and an abnormally thin CC in others suggests a possible anatomic basis for abnormal organization of cognitive functions in these patients resulting from either increased or decreased communication between the two cerebral hemispheres. The findings of the anatomic studies have suggested a connection between a thickened CC and both early onset and negative symptom patterns in schizophrenic patients. Similarly, onset of symptoms later in life and positive symptom patterns have been associated with a thinner CC. Behavioral and electrophysiological findings appear to support the idea that the same subgroups may be associated with opposite patterns of effective transfer of information between the cerebral hemispheres. Careful analysis of the transfer of information between the cerebral hemispheres for selected groups of schizophrenic patients and normal controls could provide important information about cerebral organization and possible mechanisms operative in schizophrenia.
BAEP screening for the prediction of tardive dyskinesia in schizophrenia.
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Different methods of observation affect EEG measures associated with auditory hallucinations.
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EEG lateral asymmetries in psychiatric disorders.
A number of EEG studies, including our own, have demonstrated higher levels of activity in both the low (delta and theta) and high frequency (beta 2) bands in the left (dominant) frontotemporal areas of schizophrenic patients compared to controls. Furthermore, our recent studies of power spectral density (PSD) analysis showed that even among schizophrenic patients a differentiation could be made between patients with 'left' hemisphere symptoms (e.g. thought disorder) and 'right' hemisphere symptoms (e.g. anxiety); the former characterized by large amplitude high frequency activity in the left frontotemporal area and the latter by bilateral activity of this type. The implications of these findings are discussed.
Social networks and mental health: on overview.
Research has shown that social networks can act as social support systems to promote mental health and buffer psychological stress. In this selective review the authors illuminate patterns and characteristics of social networks that maintain health and help prevent illness, explore the relationship between social networks and the course and outcome of treatment for mental illness, and describe clinical network interventions that have been used to facilitate inpatient care and maximize performance of ex-patients in the community. The authors also discuss the implications of research findings for mental health practice.
EEG differences between male alcoholics in withdrawal and those stabilized in treatment.
There is evidence that alcohol abuse and withdrawal produces cerebral impairment, some of which may be temporary and some permanent. This impairment has been found to be relatively specific in terms of brain areas affected. Recently our laboratory reported evidence that psychometrically measured impairment was systematically related to the energy in high frequency (beta-2) bands of the EEG. In the present study we attempted to determine the EEG patterns for male alcoholics undergoing withdrawal in comparison to patients who had been stabilized.
Data preprocessing applied to human average visual evoked potential P100-N140 amplitude, latency, and slope.
Data preprocessing, using principal components and Varimax rotation, was applied to 26 human average visual evoked potential (AVEP) variables representing bilateral amplitudes, latencies, and slopes from the P100 and N140 peaks. Five orthogonal factors, which accounted for about 80% of the variance, were found to describe the data from control subjects, stabilized alcoholics, and chronic nonparanoid schizophrenics. Tests of orthogonality and variance explained were employed to evaluate the results of the analysis.