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Biomedical subjects

L A Schmidt

Publications and source records attributed to L A Schmidt.

At least 19 recordsLinked to original sources
PubMed2001

Shyness, sociability, and social dysfunction in schizophrenia.

Recent bio-developmental models of shyness traits (Schmidt, L.A., Fox, N.A., 1998. The development and outcomes of childhood shyness. Annals of Child Development 13, 1--20; Schmidt, L.A. Fox, N.A., 1999. Conceptual, biological, and behavioural distinctions among different types of shy children. In: Schmidt, L.A., Schulkin, J. (Eds.), Extreme Fear, Shyness, and Social Phobia: Origins, Biological Mechanisms, and Clinical Outcomes. Oxford University Press, New York, pp. 47--66) have proposed that childhood shyness and early sociability troubles may be a precursor to pervasive social dysfunction in adulthood. An important question in testing the vulnerability model is to determine the severity of shyness among adults who have a serious social dysfunction, such as individuals diagnosed with schizophrenia. The Cheek and Buss Shyness and Sociability Scales (Cheek, J.M., Buss, A.H., 1981. Shyness and sociability. Journal of Personality and Social Psychology 41, 330--339) and the Reznick Retrospective Self-report of Inhibition (Reznick, J.S., Hegeman, I.N., Kaufman, E.R., Woods, S.W., Jacobs, M., 1992. Retrospective and concurrent self-report of behavioural inhibition and their relation to adult mental health. Development and Psychopathology 4, 301--321) were administered to 23 schizophrenia outpatients and 23 control subjects matched for age and sex. The results indicated that individuals with schizophrenia showed significantly more shyness (P<0.004), lower sociability (P<0.02) and more recollections of childhood social troubles (P<0.007) compared with the control group. Within the schizophrenia group, both shyness traits (P<0.04) and limited sociability (P<0.01) were clearly associated with interpersonal dysfunction, while significant correlations were also found between troubled sociability and negative symptoms (P<0.05). The findings of shyness traits, impaired sociability and more recollections of childhood social difficulties among stable outpatients diagnosed with schizophrenia are consistent with predictions based on a bio-developmental shyness vulnerability model.

Adult↗
PubMed2001

Association of DRD4 with attention problems in normal childhood development.

Several previous studies found an association of clinically diagnosed attention deficit hyperactivity disorder with long alleles of a variation in the DRD4 dopamine receptor gene exon III coding sequence. We evaluated the DRD4 polymorphism in a non-clinically selected sample of children for whom maternal reports of attention problems were available at 4 and 7 years of age. There was a significant elevation in attention problem scores in children carrying DRD4 long alleles that accounted for 3-4% of total variation at each age and for 5-7% of the temporally stable component of the phenotype. Our results show that the DRD4 gene influences normal as well as pathological attention processes, and the results highlight the utility of longitudinal measurements in psychiatric genetics.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

Frontal electrocortical and cardiovascular reactivity during happiness and anger.

The present study investigated electrocortical and cardiovascular reactivity during positive and negative emotion, and examined the relation of asymmetric frontal lobe activation to cardiovascular responses. Participants were 30 healthy, right-handed university students (mean age, 23.9; 60% female; 76% Caucasian). Electroencephalographic (EEG), blood pressure (BP), and heart rate (HR) responses were assessed while subjects engaged in laboratory tasks (personally-relevant recall tasks and film clips) designed to elicit happiness or anger. Happiness-inducing tasks evoked more prominent left than right frontal EEG activation, and greater left frontal EEG activation than anger-inducing tasks. However, anger-inducing tasks were, on average, associated with comparable left and right frontal EEG activation. Irrespective of emotional valence, cardiovascular activation was more pronounced during personally-relevant recall tasks than during the viewing of film clips. During anger recall, both greater left frontal EEG response (r=-0.46, P<0.02) and greater right frontal EEG response (r=-0.45, P<0.02) were correlated significantly with increased HR reactivity during the task. In addition, a right lateralized frontal EEG response during anger-inducing tasks was associated with greater concomitant systolic BP (P<0.03) and diastolic BP (P<0.008) reactivity. Exploratory analyses also indicated that men who displayed a left lateralized frontal EEG response during happiness-inducing tasks showed the greatest concomitant systolic BP and HR reactivity (P's<0.03). These findings suggest that asymmetric frontal EEG responses to emotional arousal may elicit different patterns of cardiovascular reactivity in healthy adults.

Adult↗
PubMed2000

Searching for reliable relationships with statistics packages: an empirical example of the potential problems.

Many social scientists appear to possess an overconfidence in the reliability of research results from a single, small-sample, inferential study. In this article, the authors speculate that "user-friendly" statistics packages have the potential to exacerbate statistical misinterpretation by providing researchers with a tool to explore data easily and identify what is interpreted as "reliable" relationships. This article contains an empirical demonstration of the potential problems that arise when a large number of statistical tests are interpreted. Results show that statistically significant results may be unreliable. Also, a zero relationship can erroneously appear as a medium to large effect size relationship when a small sample is used (e.g., n = 30). The authors suggest the need for multiple replications as the criterion of a reliable finding.

Adult↗
PubMed2000

Methods for evaluating policy changes in alcohol services.

Policy research assesses how outside forces affect alcohol treatment services. In this primer, we examine a range of effective methods that can be brought to bear by researchers and address the issues involved in conceptualizing and conducting studies of policy formation, implementation and policy implications. Because there is no single superior methodology for studying policy change, researchers have relied on five broad methodologies for studying policy context, formation, change and implications. We provide specific examples of each approach, addressing the following issues: data sources and samples; the problems, challenges, strengths, and limitations of the approach; and whether (and how) the method has been used in the alcohol field. The five methods are archival studies; key informant studies; ethnographic and observational studies; surveys; and meta-analyses. The strongest research designs in alcohol services research often combine methods and sources to get different vantage points on questions about policy change.

Alcoholism↗
PubMed2000

Welfare reform and the changing landscape of substance abuse services for low-income women.

Recent welfare reform policies could fundamentally change the nature of public-sector substance abuse services available to women. This review summarizes what is presently known about substance abuse services and women on welfare, and identifies limitations in our current knowledge about the potential effects of welfare reform. Five crucial areas are examined in which research on services has fallen short: (1) assessing the need for substance abuse services across a broad spectrum of welfare populations, (2) exploring the role that alcohol and drug problems play in welfare dependency, (3) examining how welfare programs can serve as pathways to alcohol and drug treatment, (4) evaluating the effectiveness and costs of innovative welfare-treatment programs, and (5) understanding systems-level adaptations in substance abuse services for women that result from changing welfare policies. We conclude that researchers who study services should take a broad view of these issues-one that considers the unique situation of poor women and single mothers, that views substance abuse within a work impairment or disabilities framework, and one that is attuned to future changes in the effects of welfare reform as the economy and labor markets undergo change.

Female↗
PubMed1999

Effects of acute prednisone administration on memory, attention and emotion in healthy human adults.

We conducted a double-blind study in order to examine the effects of high doses of prednisone on memory, attention and emotion in humans. A total of 24 healthy undergraduate males self-administered either 160 mg of prednisone (n = 12) or a placebo (n = 12) for 4 consecutive days. We examined group differences in mood, regional brain electrical activity (EEG), the startle eyeblink response, memory recall and performance on an attention task after 4 days of treatment. We found significant group differences on measures of mood and frontal EEG alpha activity on 4-day treatment. Subjects treated with prednisone exhibited a significantly greater increase in self-reported negative emotion and greater relative right frontal EEG alpha activity on 4-day treatment compared with adults in the placebo group. We also found that subjects treated with prednisone recalled fewer objects on the memory task following treatment. No significant group differences were found on posterior EEG activity, the startle eyeblink measure, or the attention measure. These findings suggest that administration of high doses of exogenous prednisone may facilitate the experience of negative emotion and shifts in frontal EEG activity, and impair some aspects of cognitive functioning in humans. The multiple roles of glucocorticoids in memory, attention and emotion are discussed.

Adolescent↗
PubMed1999

Behavioral and psychophysiological correlates of self-presentation in temperamentally shy children.

We examined temporal changes in behavior, regional brain electrical activity (EEG), heart rate, cardiac vagal tone, the startle eyeblink response, and salivary cortisol during a task designed to elicit self-presentation anxiety in a group of 7-year-olds, some of whom were classified as temperamentally shy. We found that temperamentally shy children displayed a significantly greater increase in anxious behavior, a greater increase in right, but not left, frontal EEG activity, and a greater increase in heart rate as the task became more demanding compared with their nonshy counterparts. However, the results failed to reveal any significant group differences on the startle eyeblink and salivary cortisol measures. The present findings extend our prior work, in which we found distinct patterns of psychophysiological activity on baseline measures, to differences on psychophysiological measures collected concurrently during a socially evaluative situation in temperamentally shy children.

Analysis of Variance↗
PubMed1998

Fear-potentiated startle responses in temperamentally different human infants.

Previous research has indicated that 4-month-old human infants who exhibit high degrees of motor activity and negative affect in response to the presentation of unfamiliar auditory and visual stimuli are likely to display behavioral inhibition as toddlers, while 4-month-old infants who display high degrees of motor activity and positive affect in response to the same stimuli are likely to be behaviorally exuberant toddlers. The present study examined baseline and fear-potentiated startle eyeblink responses during a stranger-approach paradigm at age 9 months in a group of infants, some of whom displayed high motor activity and negative affect and some of whom displayed high motor activity and positive affect at 4 months. The analyses revealed that the high motor/high negative group of infants exhibited a significantly greater increase in fear-potentiated startle amplitude at 9 months compared with the high motor/high positive group. There were no differences among groups of infants on baseline startle responses. These findings suggest that the origins of behavioral inhibition in early childhood may be linked to a low threshold for arousal in forebrain limbic areas.

Affect↗
PubMed1998

Domestic violence screening practices of obstetrician-gynecologists.

OBJECTIVE: To ascertain the current knowledge base and screening practices of obstetrician-gynecologists in the area of domestic violence. METHODS: We mailed a survey to 189 ACOG Fellows who are members of the Collaborative Ambulatory Research Network. Questionnaires were also mailed to a random sample of 1250 nonmember Fellows. RESULTS: Obstetrician-gynecologists are aware of the nature of domestic violence and are familiar with common symptomatology that may be associated with domestic violence. For pregnant patients, 39% of respondents routinely screen at the first prenatal visit; 27% of respondents routinely screen nonpregnant patients at the initial visit. Screening is most likely to occur when the obstetrician-gynecologist suspects a patient is being abused, both during pregnancy (68%) and when the patient is not pregnant (72%). Only 30% of obstetrician-gynecologists received training on domestic violence during medical school; 37% received such instruction during residency training. The majority (67%) have received continuing education on the subject. Years since training and personal experiences with intimate-partner violence were associated with increased screening practices. CONCLUSION: Routine screening of all women for domestic violence has been recommended by ACOG for more than a decade. The majority of obstetrician-gynecologists screen both pregnant and nonpregnant patients when they suspect abuse. However, with universal screening, more female victims of violence can be identified and can receive needed services.

Adult↗
PubMed1998

Brief communication: a software solution for reducing startle eyeblink responses.

We examined the viability of a software-based spectral method for reducing acoustic startle eyeblink responses. Fifteen young adults were presented with a 95 dB burst of white noise for 50 ms while they viewed slides that varied in affective valence. The startle EMG responses were analyzed using a discrete Fourier transform software-based spectral method. A significant linear trend was found between slide valence and startle amplitude, replicating previous work. Subjects' startle responses became more augmented as the content of the slides became more unpleasant. The advantages of software-based solutions for reducing startle EMG responses are discussed.

Adult↗
PubMed1998

Acoustic startle electromyographic (EMG) activity indexed from an electroculographic (EOG) electrode placement: a methodological note.

Acoustic startle EMG responses were indexed from a traditional EOG electrode placement in 11 young adults while they viewed slides which varied in affective valence. We found, replicating earlier work that subjects' startle responses became more augmented as the content of the slides became more negative. The advantages of using an EOG electrode placement for measuring acoustic startle responses are discussed.

Acoustic Stimulation↗
PubMed1997

Behavioral and neuroendocrine responses in shy children.

Previous research has shown that infants who display a high frequency of motor activity and negative affect at 4 months of age are likely to be behaviorally inhibited toddlers. We examined social behaviors, maternal report of temperament, salivary cortisol, and baseline startle responses at age 4 in a sample of children, some of whom displayed a high frequency of motor activity and negative affect at 4 months of age. Infants who displayed this temperamental profile were reported by their mothers as more shy at age 4 compared with other children. We also found that 4-year-olds who displayed a high frequency of wary behavior during peer play exhibited relatively high morning salivary cortisol, were reported as contemporaneously shy by their mothers, and were behaviorally inhibited at 14 months of age. There were no significant relations found between baseline startle and morning salivary cortisol and measures of shyness at age 4. We speculate that high levels of cortisol in shy children may induce changes in the amygdala, exacerbating their fearfulness.

Affect↗