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Biomedical subjects

E W Cook

Publications and source records attributed to E W Cook.

15 recordsLinked to original sources
PubMed1992

Digital filtering: background and tutorial for psychophysiologists.

Digital filtering offers more to psychophysiologists than is commonly appreciated. An introduction is offered here to foster the explicit design and use of digital filters. Because of considerable confusion in the literature about terminology important to both analog and digital filtering, basic concepts are reviewed and clarified. Because some time series concepts are fundamental to digital filtering, these are also presented. Examples of filters commonly used in psychophysiology are given, and procedures are presented for the design and use of one type of digital filter. Properties of some types of digital filters are described, and the relative advantages of simple analog and digital filters are discussed.

Analog-Digital Conversion↗
PubMed1992

Fearfulness and startle potentiation during aversive visual stimuli.

Recent experimental research suggests an association between negative affect and potentiation of the human startle reflex, as well as enhancement of this effect among fearful compared to low fear subjects. In the present study, 32 undergraduates were selected for high or low total Fear Survey Schedule scores. Acoustic startle probes were presented while subjects received warned presentations of aversive and neutral photographic slides. High fear but not low fear subjects showed potentiated short-latency cardiac acceleration and blink magnitude, and reduced blink latency, during aversive compared to neutral slides. These results support the hypothesis that affective modulation of startle is enhanced among high fear compared to low fear subjects. Considered in the context of prior findings, the results suggest that this individual difference effect generalizes across psychophysiological components of the startle reflex and diverse procedures for manipulating affect.

Adolescent↗
PubMed1991

Affective individual differences and startle reflex modulation.

Potentiation of startle has been demonstrated in experimentally produced aversive emotional states, and clinical reports suggest that potentiated startle may be associated with fear or anxiety. To test the generalizability of startle potentiation across a variety of emotional states as well as its sensitivity to individual differences in fearfulness, the acoustic startle response of 17 high- and 15 low-fear adult subjects was assessed during fear, anger, joy, sadness, pleasant relaxation, and neutral imagery. Startle responses were larger in all aversive affective states than during pleasant imagery. This effect was enhanced among high fear subjects, although followup testing indicated that other affective individual differences (depression and anger) may also be related to increased potentiation of startle in negative affect. Startle latency was reduced during high- rather than low-arousal imagery but was unaffected by emotional valence.

Emotions↗
PubMed1990

Features of "near-death experience" in relation to whether or not patients were near death.

The medical records of 58 patients, most of whom believed they were near death during an illness or after an injury and all of whom later remembered unusual experiences occurring at the time, were examined. 28 patients were judged to have been so close to death that they would have died without medical intervention; the other 30 patients were not in danger of dying although most of them thought they were. Patients of both groups reported closely similar experiences but patients who really were close to death were more likely than those who were not to report an enhanced perception of light and enhanced cognitive powers. The claim of enhancement of cognitive functions despite the likelihood that brain function had probably become disturbed and possibly diminished, deserves further investigation.

Adolescent↗
PubMed1990

Dentists' voice control: effects on children's disruptive and affective behavior.

Voice control, a punishment technique based on loud commands, has been used widely in pediatric dentistry. This study examined whether (a) loudness is a necessary component of the technique, (b) voice control actually reduces children's disruptive behavior, and (c) after treatment, children's negative affect increases. Subjects were forty 3 1/2- to 7-year-olds who posed potential behavior problems and who were scheduled for cavity restoration. Children were assigned randomly to either loud- or normal-voice groups. Children who were assigned to either group but who were not disruptive formed a nonexperimental control group. Prior to and after treatment, children reported their feelings using the Self-Assessment Mannequin. Disruptive behavior was scored using the Behavior Profile Rating Scale. Results indicated that, following loud, but not normal voice commands, children reduced their disruptive behavior (p less than .004) and self-reported lower arousal (p less than .09) and greater pleasure (p less than .10). Theoretical and practical implications of these findings are discussed.

Arousal↗
PubMed1990

Use of helium in the management of upper airway obstruction.

Inhalation therapy with the use of helium-oxygen has been advocated in the treatment of upper airway obstruction due to various causes. The therapeutic effect is secondary to a decrease in turbulent flow and airway resistance in areas of obstruction. We present a patient with acute respiratory failure secondary to upper airway obstruction caused by a tumor involving the distal trachea and proximal left mainstem bronchus. Despite assistance with a mechanical ventilator, the patient remained tachypneic and hypercarbic. Following institution of helium therapy, the patient became less short of breath and her carbon dioxide returned to a normal level. She was later weaned from mechanical ventilation and discharged from the hospital.

Administration, Inhalation↗
PubMed1978

Papillomatosis of the respiratory tract. Upper airway obstruction and carcinoma.

Metastasizing squamous cell carcinoma of the lung developed in a patient who had juvenile papillomatosis but had had no previous radiation therapy. At the same time, a significant upper airway obstruction was present. All endobronchial lesions rapidly resolved with radiation therapy, and the carcinoma was resected.

Adolescent↗
PubMedDate not supplied

The effects of aerobic exercise on cardiovascular, facial EMG, and self-report responses to emotional imagery.

This study examined the effects of exercise on subsequent psychophysiological and self-report responses to emotional imagery, using excitation-transfer theory as a guiding conceptual model. Twenty-four female undergraduates engaged in aerobic exercise (stationary cycling) for 15 minutes, and an equal number of subjects rested quietly for the same time period. All subjects then engaged in anger and sadness imagery trials. Cardiovascular, facial electromyographic, and self-report responses to the imagery were assessed. The results indicated that the subjects in the exercise group showed less peripheral vasoconstriction in response to the imagery than did the quiet rest subjects. Subjects in both groups displayed greater electromyographic activity in the depressor and zygomatic muscle regions during anger than sadness imagery, and subjects in the exercise group tended to show greater corrugator tension during sadness than during anger imagery. Few differences between the groups were found on self-report measures. These findings are discussed with reference to previous research, theoretical implications, and future directions.

Adult↗