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Biomedical subjects

V E Pollock

Publications and source records attributed to V E Pollock.

At least 37 records · Page 2Linked to original sources
PubMed1990

Topographic quantitative EEG in elderly subjects with major depression.

Some previous quantitative EEG research indicates that depressed subjects show increased alpha and beta compared to controls. In this report, absolute and relative amplitude measures of topographic EEG were used to compare elderly subjects with major depression to sex and age matched control subjects. Elderly depressed subjects showed significantly higher absolute alpha amplitude than controls, but regional differences did not specifically distinguish them. Relative alpha amplitudes, and absolute and relative measures of beta, delta, and theta did not reliably distinguish depressed and control subjects. The results are discussed in the context of previous EEG research in depression and the elderly. Methodological features and the implications of these findings for state and trait dependent conceptualizations of depression are considered.

Aged↗
PubMed1990

A metaanalysis of controlled trials of neuroleptic treatment in dementia.

Prior qualitative literature reviews about the use of neuroleptics in dementia suggest that they are "modestly effective" in treating agitation and that no single neuroleptic is better than another. To develop a more precise concept of the clinical efficacy of neuroleptics, a metaanalytic review of the existing literature was performed. From double-blind clinical trials that compared a neuroleptic with a placebo in agitated dementia patients, P values and effect-size estimates were obtained, and were assessed by metaanalytic techniques. Results indicated that neuroleptics were significantly more effective than placebo (one-tailed P = .004) and had a small effect size (r = .18). Clinically, neuroleptic treatment changed the improvement rate in agitated dementia patients from .41 to .59 (binomial effect-size display). This indicates that 18 of 100 dementia patients benefited from neuroleptic treatment (beyond that of placebo) and is consistent with the modest efficacy described in previous qualitative reviews. In six studies comparing thioridazine with another neuroleptic, and in five studies comparing haloperidol with another neuroleptic, metaanalysis results did not show that these two medications differed significantly from the comparison medications, which is not inconsistent with the opinion that no single neuroleptic is better than another.

Antipsychotic Agents↗
PubMed1990

Childhood antecedents of antisocial behavior: parental alcoholism and physical abusiveness.

Hierarchical logistic regression was used to assess the independent and interactive effects of paternal alcoholism and physical child abuse on antisocial behavior in young adult men. Men with alcoholic fathers (N = 131) did not report or exhibit more antisocial behavior than comparison subjects (N = 70). Men with physical abuse histories, however, reported more aggressive and antisocial behaviors during a clinical interview and were rated by a clinical interviewer as more likely to act out aggression. Arrest records did not distinguish the groups. There was no evidence that paternal alcoholism and childhood victimization interacted to increase the risk of antisocial behavior.

Acting Out↗
PubMed1989

Visual evoked potentials in dementia: a meta-analysis and empirical study of Alzheimer's disease patients.

A meta-analytic review of flash and pattern reversal visual evoked potential research indicates that elderly demented patients have longer P100 latencies than age-matched control subjects. In the present empirical research, patients with research diagnoses of probable Alzheimer's disease were compared with sex- and age-matched control subjects using P100 latencies of visual evoked potentials (VEP) elicited by flash and pattern reversal. As compared to control subjects, Alzheimer's disease patients showed significantly longer P100 latencies of the VEP elicited by pattern reversal; the flash P100 only marginally distinguished them. These findings are discussed within the context of VEP recording practices, patient selection, sex and age matching of control subjects, and the visual system.

Aged↗
PubMed1989

Topographic electroencephalographic alpha in recovered depressed elderly.

Late-middle-aged and elderly normal volunteers with past histories of Major Depression according to the Diagnostic and Statistical Manual of Mental Disorders (third edition-revised) criteria were compared with sex- and age-matched control subjects using topographic electroencephalographic (EEG) indices. Healthy, euthymic recovered depressed subjects showed greater alpha amplitudes than controls. Delta, theta, and beta amplitudes did not reliably distinguish the groups. Considered in the context of previous research indicating that actively depressed subjects exhibit elevated EEG alpha compared to controls, these findings raise questions concerning state and trait conceptualizations of depression and EEG alpha.

Aged↗
PubMed1989

Effects of tone stimulus frequency on late positive component activity (P3) among normal elderly subjects.

The effects of tone stimulus frequency on the auditory P3 of normal younger (n = 16) and elderly (n = 23) subjects were assessed using latency and amplitude measures. Because presbycusis is prevalent among the elderly, it was hypothesized that P3s of elderly subjects elicited by a 2000 Hz target tone would show longer latencies and smaller amplitudes than those elicited by a 500 Hz target tone. As hypothesized, the results indicated that elderly subjects showed prolonged P3 latencies under a 2000 Hz, as compared to 500 Hz target tone condition, whereas younger subjects did not show such latency differences. The P3 amplitudes of the younger and elderly groups were not, however, affected by target tone frequency. The implications of these findings in clinical geriatric ERP research are discussed.

Acoustic Stimulation↗
PubMed1988

Pattern reversal visual evoked potentials after alcohol administration among men at risk for alcoholism.

The P100 component of the pattern reversal visual evoked potential was used to compare men at high risk for alcoholism and control subjects before and after a low (0.5 g/kg) dose of ethanol. The high risk and control subjects did not differ in age, self-reported ethanol consumption, or estimates of ethanol metabolism rates, but changes in the occipital P100 latency differentiated them following ethanol administration. The P100 latency changes that distinguished high risk from control subjects were lateralized and provide preliminary evidence that perceptual visual stimulus processing is differentially affected in the two groups following ethanol administration.

Adult↗
PubMed1988

EEG identification of subgroups of men at risk for alcoholism?

Biological sons of male alcoholics constitute one group at high risk (HR) for the development of alcoholism, and were the subjects of this study. A low dose of alcohol (0.5 g/kg) was administered to HR and control subjects. On the basis of changes in the electroencephalographic (EEG) mean alpha frequency that occurred following alcohol administration, two HR subgroups were identified. Measures obtained after alcohol administration, comprising self-ratings and an observer's assessment, distinguished the HR subgroups and control subjects; measures of visuomotor performance did not. The findings are discussed in relation to two current etiological theories bearing on the development of alcoholism: a biopsychological perspective and an initial tolerance for alcohol effects.

Adolescent↗
PubMed1988

Platelet tritiated imipramine binding and MAO activity in Alzheimer's disease patients with agitation and delusions.

Decreased platelet 3H-imipramine binding density and decreased monoamine oxidase (MAO) activity have been considered as biological characteristics of several neuropsychiatric disorders, and may be related to central serotonin defects. Since serotonin system defects occur in Alzheimer's disease (AD), and decreased brain 3H-imipramine binding density, and increased brain and platelet MAO activity are reported also, we studied platelet 3H-imipramine binding density (Bmax) and platelet MAO activity in AD outpatients without antecedent psychiatric disorder. AD subjects with significant symptomatic behavioral disorder, predominantly agitation and delusions, and AD subjects without symptomatic behaviors were compared with controls. Age, sex, mini-mental state examination score, and illness duration did not distinguish the two AD groups. The agitated/delusional group showed significantly lower Bmax values than uncomplicated AD subjects or controls. MAO activity was significantly increased among female AD subjects without symptomatic behaviors compared to those who were agitated or to controls. These results indicate that 3H-imipramine binding and MAO activity may distinguish AD subjects with agitation or delusions from those without symptomatic behaviors, and suggest the existence of a biologically based Alzheimer's behavioral subtype.

Aged↗
PubMed1988

Pattern reversal visual evoked potential among men at risk for alcoholism.

The biological sons of male alcoholics, deemed to be at high risk (HR) for the development of alcoholism, were compared to control males, aged 18 to 21, using measures of the visual evoked potential elicited by checkerboard pattern reversal. Overall, the HR and control groups were not distinguished on the basis of visual evoked potential measures acquired from the occipital scalp region; however, when comparisons were restricted to right-handed subjects, the HR subjects showed more symmetry in a positive component with approximate latency of 242 ms compared with control subjects. The results are discussed in relation to hemispheric differences and alcoholism.

Adolescent↗
PubMed1987

Sex of parent and offspring in the transmission of alcoholism. A meta-analysis.

Familial studies of alcoholism were reviewed to evaluate the role of sex of parent and offspring in alcoholism transmission. Data from 32 familial alcoholism studies were evaluated by meta-analysis. The results indicated that both male and female alcoholic patients more frequently come from homes in which their father, rather than their mother, is alcoholic, even when sex differences in alcoholism prevalence rates are taken into account. Although female offspring of alcoholic mothers show alcoholism rates that are elevated relative to those expected in the general population, male offspring of alcoholic mothers do not.

Alcoholism↗
PubMed1986

Subjective and objective measures of response to alcohol among young men at risk for alcoholism.

Biological sons of alcoholic men constitute one group at high risk (HR) for the development of alcoholism. A low dose of alcohol (0.5 g/kg) was administered to HR and control subjects. Measures based on self-ratings, an observer's assessment and visuomotor performance were used to compare the HR and control subjects before and after alcohol administration. Results showed HR subjects' self-ratings of intoxication and somatic symptoms were significantly lower than those of control subjects after alcohol administration. Measures based on an observer's assessment of the two groups did not distinguish them, but one measure of visuomotor performance did. Because the HR and control subjects did not differ in self-reported alcohol consumption or blood alcohol levels acquired in this study, it appears unlikely these factors could account for the differential responses to alcohol administration in HR and control subjects.

Alcohol Drinking↗
PubMed1986

Brain responses to sine wave modulated light (SML): reliability and relationship to spontaneous EEG.

Brain activity elicited by sine wave modulated light and spontaneous EEGs were obtained from 11 healthy adult males on two separate occasions. Within-subject correlations (test-retest correlation coefficients) for SML responses were high, and comparable to reliability estimates of spontaneous EEG activity in this sample. Reliability of the spontaneous EEG was evaluated using two measures: absolute and relative power. Although their magnitudes were comparable, the test-retest correlation coefficients for the right occipital were consistently higher than those of the left using absolute measures; this pattern was not reflected by test-retest correlations based on relative EEG measures. Finally, the SML responses to 5, 15, 18 and 24 Hz stimulation frequency rates correlated most highly with absolute measures of spontaneous EEG beta, whereas the SML response to 10 Hz stimulation yielded the highest correlations with spontaneous alpha activity.

Adult↗
PubMed1983

The EEG after alcohol administration in men at risk for alcoholism.

The biologic sons of alcoholics constitute a group at high risk (HR) for alcoholism. A 0.5-g/kg dose of alcohol was administered to HR and control subjects aged 19 to 21 years. Blood alcohol concentration measurements failed to distinguish HR from control subjects, but quantitative measurements of EEG alpha activity differentiated them. The HR subjects exhibited greater increases in slow alpha energy and greater decreases of fast alpha energy after alcohol administration than controls; the HR subjects also showed greater decreases in mean alpha frequency after alcohol administration. These EEG findings suggest that subjects at high risk for alcoholism are physiologically more sensitive to alcohol than control subjects.

Adult↗
PubMed1981

Effects of caffeine on resting EEG and response to sine wave modulated light.

A double blind, placebo controlled study was designed to assess transient caffeine effects on spontaneous and evoked brain activity in man. Twelve normal males received 200 mg caffeine citrate or placebo on separate occasions. EEG from left and right occipital regions was recorded in the absence of stimulation and during the response to sine wave modulated light (SML). The photic stimulation frequencies were 5, 10, 15, 18 and 24 c/sec. EEG power at frequencies corresponding to fundamental and selected harmonics of stimulation frequencies was obtained. The time course of response to SML was studied over a period of 2 min. Caffeine reduced the EEG power under resting conditions and during SML stimulation. This reduction was statistically significant at 10 and 15 c/sec. At 24 c/sec, caffeine reduced the fundamental SML response, but not the resting EEG power. Evaluation of the SML response time course did not reveal any consistent tendencies. It appears that the response is sustained in a stable way over the period of 2 min.

Adult↗