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Biomedical subjects

J C Kircher

Publications and source records attributed to J C Kircher.

12 recordsLinked to original sources
PubMed2000

Cardiovascular and electrodermal responses to support and provocation: interpersonal methods in the study of psychophysiological reactivity.

This study examined the joint and independent effects of experimentally manipulated social contexts and individual differences in hostility and perceived social support on physiological responses to a social stressor, while illustrating the use of the interpersonal circumplex for integrative social psychophysiological research. Undergraduate women completed a speech task in a supportive, neutral, or provoking context and completed measures of hostility and perceived social support. The provoking context evoked the largest blood pressure and heart rate (HR) responses, followed by the neutral and the supportive context. Social context also influenced HR and electrodermal reactivity during task preparation. Hostility elicited higher systolic blood pressure (SBP) reactivity during preparation, speech, and recovery. Perceived social support interacted with context to affect SBP and HR during speech and preparation. The roles of interpersonal characteristics and contexts in the physiological stress response and the utility of interpersonal methods in studying these associations are discussed.

Adult↗
PubMed1997

The effects of social context and defensiveness on the physiological responses of repressive copers.

In previous research (T.L. Newton & R.J. Contrada, 1992), social context was found to moderate exaggerated physiological reactivity among individuals identified as using a repressive coping style. In this experiment, 119 undergraduates were classified into low-anxious, high-anxious, repressor, and defensive high-anxious coping categories. All participants completed a stressful speech task under either a public or private social context condition. The experimental social context was related to physiological reactivity and self-reported affect but did not moderate reactivity among repressive copers. Additionally, reactivity among repressive copers was not attributable to high defensiveness alone. Consistent with a theory of emotional inhibition, nonspecific skin conductance responses, but not heart rate, discriminated between repressors and nonrepressors.

Adaptation, Psychological↗
PubMed1997

Social determinants of cardiovascular reactivity: effects of incentive to exert influence and evaluative threat.

The effects on cardiovascular reactivity of incentive to influence the judgements of the experimenter and the threat of social evaluation were examined in a sample of 60 male and 60 female undergraduates. Participants either were guaranteed $5.00 to prepare and deliver a brief speech or were told that the money was contingent on an evaluation by the experimenter. Participants believed that their speech would be rated for either simple clarity or verbal intelligence. The contingent incentive increased systolic blood pressure reactivity by 6.5 mmHg (32%). Evaluative threat increased systolic reactivity by 7.1 mmHg (36%). These interpersonal processes could increase the risk of cardiovascular disease and are likely to affect the degree of cardiovascular reactivity in laboratory studies.

Adult↗
PubMed1997

The role of comparison questions in physiological detection of deception.

Comparison questions in physiological detection of deception were studied with 60 "guilty" and 60 "innocent" participants in a mock crime experiment. Different types of comparison questions were used in four conditions: relevant-irrelevant (R-I) participants answered only relevant and neutral questions; trivial directed lie participants were instructed to lie to three of the six neutral questions; personal directed lie participants were instructed to lie to personally relevant questions; and probable lie participants received traditional probable lie comparison questions. Respiration, cardiovascular, vasomotor, and electrodermal activity were recorded. Manipulation of the comparison questions produced different patterns of physiological responses for innocent but not for guilty participants. The R-I test produced an unacceptable rate of false positive decisions.

Adolescent↗
PubMed1996

Mental and physical countermeasures reduce the accuracy of the concealed knowledge test.

The effects of a physical (pressing the toes to the floor) and a mental (counting backward by sevens) countermeasure on the concealed knowledge test (CKT) were examined in a mock crime experiment with 40 subjects. Some knowledgeable subjects were informed about the nature of the CKT and were trained in the use of a countermeasure, whereas others remained uninformed. All subjects were offered a monetary reward if they could produce a truthful outcome. Subjects were tested using standard field techniques and instrumentation. The physical and, to a lesser extent, the mental countermeasures reduced the accuracy of the CKT. These results clearly demonstrate that the CKT has no special immunity to the effects of countermeasures.

Adult↗
PubMed1996

Children and adolescents with neurofibromatosis 1: a behavioral phenotype.

Twenty 6- to 17-year-old children with neurofibromatosis 1. (NF1) were compared to 20 age- and sex-matched siblings on a wide range of neuropsychological and behavioral dimensions. In familial cases, diagnostic status was confirmed by gene linkage with greater than 98% accuracy. Visual examinations that included assessments of visual evoked responses (VER) were performed on subjects with NF1. Forty-two percent of NF1 subjects had abnormal VER and underwent magnetic resonance imagery or computed tomography scans of the brain. On a variety of skills, subjects with NF1 performed more poorly than unaffected siblings. Children with NF1 were found to be less competent on measures of cognitive, language, and motor development, visual-spatial judgment, visual-motor integration, and academic achievement. Learning disabilities were common in children with NF1. Parents and teachers reported that NF1 subjects had internalizing problems and difficulty interacting with peers. A behavioral phenotype for NF1 and recommendations for preventative interventions are proposed.

Adolescent↗
PubMed1995

Polygrapher's dilemma or psychologist's chimaera: a reply to Furedy's logico-ethical considerations for psychophysiological practitioners and researchers.

We respond to Furedy's article in this journal where he raised an issue he referred to as the "Polygrapher's dilemma" (Furedy, J.J. (1993) Int. J. Psychophysiol., 15: 263-267). Furedy claimed that the control question test, the most commonly applied psychophysiological detection of deception test, is inherently subjective and harmful to subjects in both the field and the laboratory. Fortunately, Furedy's arguments were based on inaccurate representations of the control question test and on flawed logic. To correct Furedy's misrepresentations, we present an accurate description of how the control question test is used and evaluated. We then examine the results of empirical research that address Furedy's concerns. Furedy's concerns are found to be lacking on almost all counts. Finally, we discuss the findings from several studies that Furedy failed to mention but are directly relevant to the issues he raised.

Ethics, Professional↗
PubMed1995

Effects of methylphenidate on reward strength in boys with attention-deficit hyperactivity disorder.

OBJECTIVE: To test the hypothesis that methylphenidate reduces thresholds for reward in children with attention-deficit hyperactivity disorder (ADHD). METHOD: A double-blind crossover design was used in which 16 ADHD boys, aged 8 to 13 years, received methylphenidate on one testing occasion and placebo on another. On each occasion, subjects performed a task that required progressively greater numbers of button presses to earn a fixed monetary payoff. RESULTS: The "breaking point" above which the hyperactive child was unwilling to continue with the task was significantly higher during drug than placebo trials. CONCLUSIONS: The results support an assumption that underlies the reward system dysfunction hypothesis of ADHD, and they suggest that reward mechanisms may underlie the therapeutic effects of stimulants observed across a wide range of tasks and settings.

Adolescent↗
PubMed1994

Mental and physical countermeasures reduce the accuracy of polygraph tests.

Effects of countermeasures on the control-question polygraph test were examined in an experiment with 120 Ss recruited from the general community. Ss were given polygraph tests by an examiner who used field techniques. Twenty Ss were innocent, and of the 100 guilty Ss, 80 were trained in the use of either a physical countermeasure (biting the tongue or pressing the toes to the floor) or a mental countermeasure (counting backward by 7) to be applied while control questions were being presented during their examinations. The mental and physical countermeasures were equally effective: Each enabled approximately 50% of the Ss to defeat the polygraph test. The strongest countermeasure effects were observed in the cardiovascular measures. Moreover, the countermeasures were difficult to detect either instrumentally or through observation.

Adult↗
PubMed1987

The psychophysiological nature of premature ejaculation.

The hypothesis that premature ejaculators (PEs) are less able than non-premature ejaculators (NPEs) to evaluate accurately their level of physiologically determined sexual arousal was tested. Twenty-six men (13 PEs and 13 NPEs) viewed a variety of videotaped vignettes, some of which were excerpts from sexually explicit films. Concurrent subjective (self-report) and objective (plethysmograph) ratings of sexual arousal were taken. Data revealed that both the PEs and NPEs were equally accurate in assessing their level of physiological sexual arousal. These results and those from a sexual history questionnaire were used to evaluate several hypotheses regarding the nature and etiology of premature ejaculation.

Adult↗