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Biomedical subjects

D W Harrison

Publications and source records attributed to D W Harrison.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cerebral asymmetry in facial affect perception by women: neuropsychological effects of depressed mood.

40 right-handed women, half of whom had been classified with depressed mood and the other half as nondepressed, participated in a tachistoscopic study of the influence of depressed mood on the cerebral hemispheric processing of Ekman and Friesen's 1976 happy, sad, and neutral emotional faces using a forced-choice reaction-time paradigm with only happy and sad alternatives as response manipulanda. The women with depressed mood were also characterized by elevated scores on both state and trait anxiety, suggestive of an anxious-depressive state with heightened arousal. Primary findings for the tachistoscopic data indicated that women with depressed mood as compared to nondepressed women displayed significantly faster reaction times to sad faces presented in the right visual field and happy faces presented in the left visual field. These results are suggestive of differential arousal of both the left and right cerebral hemispheres in this sample of anxious-depressed women and are discussed in light of arousal theory.

Adolescent↗
PubMed1994

Is right hemisphere decline in the perception of emotion a function of aging?

The hypothesis that the right cerebral hemisphere declines more quickly than the left cerebral hemisphere in the normal aging process was tested using accuracy and intensity measures in a facial recognition test and using response time and response bias measures in a tachistoscopic paradigm. Elderly and younger men and women (N = 60) participated in both experiments. Experiment 1 required facial affect identification and intensity ratings of 50 standardized photographs of 5 affective categories: Happy, Neutral, Sad, Angry, and Fearful. The elderly were significantly less accurate in identifying facial affective valence. This effect was found using negative and neutral expressions. Results for happy expressions, however, were consistent with the younger group. In Experiment 2, age differences in hemispheric asymmetry were evaluated using presentation of affective faces in each visual field. Following prolonged experience with the affective stimuli during Experiment 1, the elderly showed heightened cerebral asymmetry for facial affect processing compared to the younger group. Both groups showed a positive affective bias to neutral stimuli presented to the left hemisphere. Elderly and younger subjects scored significantly higher on Vocabulary and Block Design subtests of the WAIS-R, respectively. Overall, the findings suggest that the elderly have more difficulty processing negative affect, while their ability to process positive affect remains intact. The results lend only partial support to the right hemi-aging hypothesis.

Adolescent↗
PubMed1993

A test of Kinsbourne's selective activation model.

Kinsbourne's selective activation model (1985) was investigated in a sample of 28 strongly right-dominant males. Priming manipulations were hypothesized preferentially to activate a hemisphere and to decrease reaction time on an affect recognition task in the contralateral visual field. The left hemisphere manipulation consisted of subvocal verbal rehearsal, while imagery served as the right hemisphere task. Baseline performance was evaluated via a control condition. No priming was found, but the experimental tasks had significant interference effects. Interference was noted across visual fields for both experimental manipulations relative to the control condition, suggesting the hemispheres were not preferentially recruited. Furthermore, the processing of happy faces was more susceptible to interference than was that of angry faces. Conceptual and methodological issues are presented to account for the former finding and data relevant to the laterality of affect perception may explain the latter.

Adult↗
PubMed1991

Concurrent verbal interference of right and left proximal and distal upper extremity tapping.

The purpose of this study was to investigate crossed and uncrossed control of the proximal (upper arm and shoulder) and distal (lower arm and hand) musculature of the arms using the dual-task paradigm. Forty-one strongly right-handed men performed a tapping task using primarily the musculature of the upper or lower arms, with and without concurrent verbal processing demands. The results showed that the left distal region was distinguished from the other three effector locations by its relative insensitivity to the demands of the dual-task (verbal processing) condition. Rapid alternating movements of the left arm were functionally independent from the left index finger location in response to dual-task demands. Dual verbal and tapping demands at this effector produced greater interference on both the primary and secondary task. The results preclude the attribution of interference effects to manual dominance factors alone. The results generally support anatomical accounts of increased ipsilateral control over left side arm but not hand movements. Neither the traditional cognitive hemispheric model nor the manual dominance hypothesis were adequate in accounting for the results. An alternative generalized capacity hypothesis was required to account for performance at the LE.

Adolescent↗
PubMed1991

Child- or adult-directed speech and esteem: effects on performance and arousal in elderly adults.

The effects of speech type and esteem level on performance, physiological arousal level, and subsequent esteem were explored in the present study of older individuals. The cardiovascular measures of blood pressure and heart rate showed the procedures to be stressful but produced inconclusive results related to the grouping variables. Practice effects were found for all participants on all tasks, regardless of group membership. On the mirror-tracing task, low esteem participants and participants who received child-directed speech made fewer errors than high esteem participants and participants who received adult-directed speech. The results indicate that older adults perform difficult tasks better with clarified instructions given in an attention-getting manner. This may be especially true on timed tasks where cautious response styles facilitate accuracy of performance (e.g., mirror-tracing tasks). The results were contradictory to more intuitive accounts of child-directed speech negatively impacting self-esteem and performance in this age group.

Achievement↗
PubMed1991

Cerebral asymmetry in dementia: effect of context on hemi-attention.

The duration of the orienting response toward the left or right hemispace as a function of bright light and noise levels was evaluated in 6 demented elderly patients. Tentative findings of cerebral asymmetry suggest light may differentially activate the left hemisphere.

Acoustic Stimulation↗
PubMed1990

The vascular orienting response and the law of initial values.

Vascular responses following exposure to the experimental situation (a type orienting reflex) were evaluated in 6 male subjects. Bilateral skin temperature was recorded from the head and finger regions for the duration of the experimental session. The interaction of Location X Trial (p less than or equal to 0.002) showed reliable differences between the head and finger sites and the left and right forehead sites early in the session followed by differential rates of change during the session across sites. The results support the recent claim for the importance of the law of initial values in finger temperature research and extend the findings to multiple site comparisons in the absence of hemispheric task demands. The vascular orienting reflex to the experimental context may augment initial value differences among recording sites.

Adolescent↗
PubMed1990

Manual dexterity, strength, fatigue, and perseveration: an initial test of asymmetry in cerebral activation.

50 right-handed men were evaluated on right and left hand-grip strength, fatigue, and perseveration tasks and on a finger-tapping task. Subjects were tested in combined ambient sensory conditions of bright light and noise, bright light and quiet, dim light and noise, and dim light and quiet to provide an initial test of asymmetrical activation of the hemispheres. Analysis did not support the hypothesized asymmetry in activation. However, increased fatigue and perseveration were found using the left hand.

Adolescent↗
PubMed1990

Functional asymmetry for facial affect perception in high and low hostile men and women.

The influence of cerebral asymmetry in the perception of affect on Type A behaviour was examined. Twenty-five men and 25 women classified as Type A or Type B, using the Framingham Type A Scale (FTAS) and the Cook-Medley Hostility Inventory (CMHO), participated. Subjects were required to identify the facial affect depicted in Ekman and Friesen's (1978) angry, happy, and neutral stimuli using a forced-choice reaction-time paradigm with only angry or happy alternatives signified by the respective response manipulanda. Stimuli were presented within the left or right visual fields tachistoscopically. The results showed faster affect perception by right hemisphere (LVF), hemispheric differences related to affective valence, and sex differences in affect asymmetry. Type A and Type B groups differed in the forced identification of neutral stimuli revealing affective bias but not processing speed differences on this perceptual task.

Adolescent↗
PubMed1990

Sex differences in the functional asymmetry for facial affect perception.

Twenty-six right-hand-dominant women and 26 right-hand-dominant men were required to identify the facial affective expression of Ekman and Friesen's (1978) angry, happy, and neutral stimuli using a forced-choice reaction-time paradigm with only angry or happy alternatives signified by the respective response manipulanda. Stimuli were presented within the left or right visual fields to provide additional data on sex differences in the lateralized processing of facial affective stimuli. The results supported the hypothesis of greater laterality among men with equivalent response times for women and men to stimuli within the right but not the left visual fields. Men were significantly faster in processing affective facial information within the left visual field. The results also indicated that differential rates of learning occur in affective tachistoscope tasks for happy and angry stimuli. Thus, opposite conclusions may be derived from procedural differences among studies in the number of identification trials employed.

Adolescent↗
PubMed1990

Alternate forms of the AVLT: a procedure and test of form equivalency.

The Rey Auditory Verbal Learning Test is frequently used in neuropsychological evaluation and research. However, its utility in the measurement of progressive change is limited by the availability of alternate and equivalent forms. Criteria were developed for word selection to generate new lists. Two alternate forms generated according to these criteria, as well as the original Key AVLT and alternate form, were administered to elderly Medical Center patients and undergraduate volunteers. All four AVLT forms yielded comparable mean recall scores, and alternate form reliability coefficients for each trial varied from.67 to.90. Conclusions from this study, though, must be made with caution as the sample size used was small.

Journal Article↗
PubMed1989

Pupillometric assessment of arousal to sexual stimuli: novelty effects or preference?

The pupillary response of male and female subjects to various sexual stimuli was examined. Change in pupil size was compared using light and dark control slides and nude male and female, heterosexual, and homosexual stimulus slides. Attempts were made to control for the many confounds inherent in pupillometric research. Pupil size was measured using video-recording techniques that magnified pupils to an easily measured size. Greater pupil change was found when the stimulus slide was preceded by a relatively lighter control slide. In addition, pupil change was related to familiarity with the stimulus slide and the relative pupil response changed as subjects gained experience with the stimulus material. Explanations and implications for further research are discussed.

Adult↗
PubMed1989

Extracranial and digital vascular events: an analysis of methods in BVP amplitude and biofeedback research.

The purpose of the present study was to assess and compare the effects of within and between-session exposure to environmental context on left temporal artery pulse amplitude, right temporal artery pulse amplitude, and left digital pulse amplitude. Subjects were individually tested for 20 min daily over a period of eight consecutive days. A significant interaction was found for Position X Interval. These results show that exposure to the experimental context occurs with diametrically opposite effects on temporalis and digital pulse amplitude within session. Moreover, these results would support the hypothesis that controversial findings within the headache and biofeedback literature may be partially attributable to methodological differences where, for example, different authors use different transducer locations and/or evaluate pulse amplitude at different points within or among sessions. Indeed, research on the effects or lack thereof of therapeutic manipulations may have little or nothing to do with the intervention or experimental manipulations themselves. These effects may be masked or augmented by subject and methodological confounds during baseline and testing conditions.

Adolescent↗
PubMed1989

Age differences in cardiovascular and cognitive performance under noise conditions.

Ambient white noise (80 dB), compared with quiet (52-dB) testing conditions, improved the performance of elderly and younger subjects on simple addition. Reliable age-related interactions were found on health measures of systolic and diastolic blood pressure, as well as heart rate. Heightened sensory conditions reduced the physiological measures of arousal in the younger group, whereas significant cardiovascular reactivity was found among the older group. The results are suggestive of the potential for increased cardiovascular risk as a function of sensory stimulation in the elderly despite improvements on cognitive tasks. Additional research is needed to evaluate the multidimensional effects of extended sensory stimulation on the elderly.

Adolescent↗
PubMed1988

Human factors and design evaluation of digital blood pressure/pulse meters.

This study provides a comparison of self-measurement blood pressure devices, with respect to the standards published by the American National Standards Institute/Association for the Advancement of Medical Instrumentation and statements from the American Heart Association and the National High Blood Pressure Education Program. The results show a wide disparity among the recommendations of select committees, on issues of education and compliance and on design features of this instrumentation. Procedural problems in determining compliance in this study highlight the need for improved objectivity in statements in national standards and for improved awareness of those statements by manufacturers.

Blood Pressure Determination↗
PubMed1988

Blood pressure reactivity and bias vary with age in a comparison of traditional and automated methods of measurement.

This study examined the effects of initial-reading reactivity and measurement methods of blood pressure across different age groups. Subjects were men and women (n = 132), 17 to 96 years of age. Two measurements were obtained from each subject, with a 1-min interval between trials. Each trial consisted of concurrent measurements from each arm, using a standard mercury manometer and an automated blood pressure monitor for use at home. A double-blind control procedure was used. Significant effects were obtained for age (younger, middle, and older age groups), method by trial and age by trial. The blood pressure reactivity and the effect of observer bias varied across age groups. The results support the hypotheses that blood pressure readings decline across trials; that observer bias using traditional methods is sufficient to mask this decline; and that the extent of reactivity and subsequent decline is dependent on age or an age-related increase in blood pressure. Implications of these findings for the use of automated monitoring instruments designed for use at home are discussed.

Adolescent↗
PubMed1987

Home health-care: accuracy, calibration, exhaust, and failure rate comparisons of digital blood pressure monitors.

This study provides a detailed comparison of 22 digital, blood pressure monitors intended for home use. Blood pressure and pulse-rate readings from each electronic monitor were compared with concurrent measures obtained using the mercury column and auscultation. Correlation coefficients and linear regressions were performed to evaluate accuracy. Separate analyses of variance were used to determine significant calibration errors for each model. The results showed considerable disparity among available home monitors under controlled testing conditions. Variables associated with accuracy and home use by the layperson are discussed.

Adolescent↗