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Biomedical subjects

E W Howland

Publications and source records attributed to E W Howland.

10 recordsLinked to original sources

Effects of oral morphine on cold pressor tolerance time and neuropsychological performance.

We investigated the analgesic effects of escalating doses (0.214, 0.286, 0.357, and 0.429 mg/kg) of oral morphine on tolerance to painful cold pressor in a double-blind, active placebo-controlled (diphenhydramine) study in 45 normal volunteers. The highest dose of morphine administered is equivalent to the starting dose recommended by the Agency for Health Care Policy and Research for the management of cancer pain and acute postoperative pain. We assessed analgesia in terms of cold pressor tolerance time and self-reported ratings of pain intensity and unpleasantness. Subjects receiving the highest dose of oral morphine showed significantly higher tolerance time than subjects receiving diphenhydramine. Neither morphine or diphenhydramine significantly reduced ratings of pain intensity and unpleasantness. Neuropsychological testing revealed that the two highest doses of morphine impaired the episodic retrieval of a word list, but the same doses did not affect motor, perceptual, or attentional tasks.

Administration, Oral↗

Whole head mapping of magnetic fields following painful electric finger shock.

Painful intracutaneous electric finger shock was delivered to the fifth digit of the non-dominant hand of five healthy volunteers. Whole head evoked magnetic field maps were collected and cortical localizations were calculated using local sphere equivalent current dipole fits. MRI scans were used to identify the anatomical structures where magnetic field sources were located. Anatomically, sources were identified bilaterally in the primary somatosensory region and SII-Insula regions. Additionally, frontal operculum sources were observed contralaterally in two subjects. Temporally, an initial contralateral SI activation at 40-60 ms was followed by several SII-Insula responses over the next several hundred milliseconds (ms). These SII-Insula responses were often interspersed with additional activations of the SI region. These later responses were observed in both hemispheres.

Adult↗

Altering a dominant response: performance of psychopaths and low-socialization college students on a cued reaction time task.

The passive avoidance learning deficits of disinhibited Ss have been attributed to their difficulty inhibiting dominant responses. To date, evidence for this hypothesis has been derived from complex tasks. In two experiments, a cued reaction time task requiring no learning or memory was used to evaluate the degree to which groups of disinhibited Ss inhibit simple dominant responses. Disinhibited groups were incarcerated psychopaths identified with Hare's (1985) Psychopathy Checklist and undergraduate males who scored low on the Socialization Scale. Both disinhibited groups committed more errors than controls on trials containing misleading cues, but in both samples, findings were limited to trials in which Ss expected to make right-hand responses. Although alternative interpretations are possible, these data are consistent with the proposal that disinhibited individuals are less likely to inhibit well-established dominant responses.

Adult↗

Tonic changes in alpha power during immersion of the hand in cold water.

Phasic event-related desynchronization (ERD) of alpha activity briefly follows many types of stimulation. In order to define EEG changes resulting from longer stimulation. EEG records were made before and during hand immersion into cool and painfully cold water (cold pressor). Five minutes of 13-lead EEG records were obtained from 14 subjects for each condition. EEG frequency analysis was performed on artifact-free epochs from 60 to 240 sec following immersion. Following an initial phasic decrease in alpha power during cold water immersion, there was an augmentation of alpha power (8-12 Hz) in bilateral frontal and posterior electrodes. This augmentation was largely the result of an increase in the low alpha band (8-10 Hz). Alpha power at both central electrodes C3 and C4 changed little during cold water immersion. Cool water immersion produced less alpha power augmentation than cold water immersion. These observed changes were primarily in the high alpha band (10-12 Hz) and were larger in electrodes ipsilateral rather than contralateral to the stimulation. There was also an increase of beta bilaterally in frontal and posterior regions with cold water immersion. Our data demonstrate sustained topographic EEG responses during tonic stimulation from hand immersion in painfully cold water. These changes differ from those produced by stimulation with cool water immersion.

Adolescent↗

Ocular and stabilization feedback: an evaluation of two EMG biofeedback control procedures.

This study evaluated the adequacy of two novel EMG biofeedback control procedures. During a single training session, 36 subjects received either contingent EMG feedback from the frontal region (Veridical), contingent feedback for vertical eye movements (Ocular), or a feedback condition where the signal increased with deviations in any direction from baseline EMG levels (Stabilization). The results supported the use of Ocular but not Stabilization feedback as a control procedure in frontalis EMG biofeedback studies. Ocular feedback did not produce reductions in frontalis EMG but did lead to changes in subjective measures of nonspecific treatment effects that were at least comparable to those obtained with Veridical feedback. Stabilization subjects produced small but significant reductions in EMG, felt the most bored as a result of their feedback training, and were the most likely to rate themselves as having received false feedback. The implications of attribution theory and multiprocess relaxation theory for the evaluation of nonspecific treatment effects are discussed.

Adolescent↗

Versatility in computer automation for biofeedback: the behavioral assessment and rehabilitative training system (BARTS).

User versatility in a system for computer-automated biofeedback training is the degree to which the assessment and training parameters may be altered by the user's employing English language or other simple code, that is, without altering the system's applications software. The Behavioral Assessment and Rehabilitative Training System (BARTS) includes a design and control program that allows for the specification of assessment and training protocols by persons who are entirely lacking in computer programming skills. This paper describes the logic for data acquisition and training that is incorporated in the BARTS, describes the parameters that must be specified in constituting unique assessment or training protocols, and illustrates the system's application in a research-oriented biofeedback clinic.

Biofeedback, Psychology↗

Toward the automated measurement of the type-A behavior pattern.

Sixty-six structured interviews that were rated by Rosenman on a 5-point Type A/B behavior pattern scale, were scored by means of a semi-automated system for verbosity, voice volume and the temporal pacing of speech. A significant negative correlation obtained between interviewees' A/B ratings and their reaction-time scores; significant positive correlations obtained between their behavior type ratings and their voice volume and duration of vocalization scores. A regression equation consisting of reaction-time and voice volume scores correctly classified the A/B ratings of 89 percent of the interviewees. The significant correlations that were obtained between the interviewer's and the interviewees' speech patterns emphasize the need for standardizing the interviewer's style. Finally, the findings suggest that anxiety-arousal is a mediating variable in the relationship between Type-A behavior and coronary heart disease.

Adult↗

Measuring effect magnitude in repeated measures ANOVA designs: implications for gerontological research.

Many methodologists advocate reporting effect size (ES) measures to assess the importance of observed differences. Unlike significance levels, these measures are independent of sample size. A second use of ES measures, particularly relevant to gerontological research, is to assert the null hypothesis by demonstrating the smallness of an effect. However, ES estimation is problematic in many commonly-used repeated measures ANOVA designs: If the additivity assumption is invalid and the design includes a fixed within-subject factor, the sample estimates of ES will be biased negatively. Our paper offers an alternative estimation procedure that can compensate for that bias. We define the lower and upper bounds of an interval within which lies the unbiased ES estimate. Further, we assert that for most design situations violation of the additivity assumption has a relatively small effect on the ES estimate. In addition, we provide a detailed, concrete example that should facilitate calculation of ES in repeated measures designs.

Aging↗

Late pain-related magnetic fields and electric potentials evoked by intracutaneous electric finger stimulation.

Surface magnetic and electric recordings were used to localize the sources of late pain-related magnetic fields and electric potentials, evoked by painful intracutaneous electric finger stimulation. We find that the source of the P90m component of the evoked magnetic field lies in the finger area of the primary somatosensory cortex; the sources of the N150m and P250m are found to reside in the frontal operculum. These findings are unexpected from the evoked electric potential data, which suggest a central location for these sources. We also note that the interpretation of the electric data was confounded by the presence of an alpha-like oscillation, which overlapped many components of the evoked potential.

Brain↗