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Biomedical subjects

J R Livesay

Publications and source records attributed to J R Livesay.

8 recordsLinked to original sources
PubMed1999

Pilot study on the relationship between personality traits and skin conductivity of specific surface points as measured by Motoyama's apparatus.

This pilot study used Motoyama's electrodermal response-measuring apparatus to test resting skin conductivity from 28 extremity digit surface coordinates of 33 subjects who also were administered the Eysenck Personality Inventory on an alternatively assigned basis for the dimensions of extraversion and neuroticism. Correlations show significant relationships between neuroticism and extraversion raw scores on two of the 14 bilateral finger surface coordinates.

Adult↗
PubMed1998

Covert neuromuscular activity of the dominant forearm during visualization of a motor task.

This study evaluated specific covert neuromuscular activity during a silent visualization exercise. 30 subjects participated in a dual-baseline single-subject procedure. The experimental test condition required the subjects to visualize themselves squeezing a hand-size rubber ball as tightly as possible for 1 min. In the comparison test condition, subjects were asked to imagine the 'sun setting on the horizon' for 1 min. Visualization of the motor task brought about significant (p <.05) increases in dominant forearm EMG (microV) and heart-rate activity (bpm) from rest to the experimental test condition. Nondominant forearm activity showed no significant changes from rest to either test condition, and heart-rate activity (bpm) showed no significant change from rest to the comparison visualization task.

Adult↗
PubMed1995

Covert speech behavior during video-viewing tasks with and without an overt speech soundtrack.

This pilot study tested the prediction that covert speech activity measured by lip EMG(mu v) is significantly greater during the presentation of prerecorded speech than in a 'speechless' video-viewing test condition and conditions of rest. A single-subject multiple-baseline design was used and nondominant forearm EMG(mu v) activity was also measured for comparison purposes. Analysis showed a significant increase in lip EMG(mu v) activity in 1 out of 2 rest-to-test conditions involving the presentation of prerecorded overt speech. There was no significant difference in the subjects' mean lip EMG(mu v) values across 3 test conditions, however.

Adult↗
PubMed1994

EMG and cardiovascular responses to emotionally provocative photographs and text.

Previous studies on the psychophysiology of human emotion have repeatedly shown general and occasionally specific facial EMG (mu v) and covert cardiovascular response relationships to emotionally provocative photographs. Less clear are the relationships between psychophysiological response indices measured during the silent reading of emotionally charged versus emotionally neutral text. In this study, 12 adult subjects were presented two emotionally loaded color and black-and-white photographs and two brief newspaper articles, one emotionally charged and the other emotionally neutral in content. Each independent stimulus was presented for 1 min., preceded by a rest according to a multiple baseline-reversal design. Subjects evaluated each pictorial and textual stimulus condition according to adjective dimensions on 7-point rating scales. Mean values for corrugator supercilii EMG (mu v), upper trapezius EMG (mu v), surface temperature (degrees F), and heart rate (bpm) measured by finger photoplethysmography were measured during each rest and test period. Significant increases in the subjects' mean corrugator supercilii EMG (mu v) measures were observed during all color and black-and-white photograph presentations for both emotional and neutral content. As predicted, the subjects' mean corrugator supercilii EMG (mu v) measures increased significantly while silently reading text with an obvious unpleasant emotional tone. A significant positive relationship was observed between the subjects' mean ratings and mean corrugator EMG (mu v) difference values for the emotionally loaded color photographs.

Adult↗
PubMed1986

Clinical utility of Wechsler's Deterioration Index in screening for behavioral impairment.

Utilizing the Halstead Impairment Index derived from the Halstead-Reitan neuropsychological battery as the defining criterion for the presence or absence of brain-behavior deficiency, the current investigation examined the hypothesis that the Wechsler Deterioration Index is a predictively efficient measure for screening behaviorally impaired subjects from nonimpaired subjects. Subjects were 35 adult examinees consecutively referred for neuropsychological assessment and were divided into two groups on the basis of Halstead indices. The impaired group included 12 men and 7 women whose ages ranged from 17 to 59 yr.; the nonimpaired group were 10 men and 6 women whose ages ranged from 16 to 43 yr. The Wechsler indices for the impaired and nonimpaired groups represent two significantly different populations with the discrepancy between the two groups' scores falling within the predicted direction. A positive correlation between the Halstead Index and the Wechsler Index was indicated for all subjects, but no significant relationship between the Halstead Index and other psychometric ratios. Implications of the results are restricted because there was no normal control group and independent neurological screening was limited.

Adolescent↗