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Biomedical subjects

Max E Levine

Publications and source records attributed to Max E Levine.

4 recordsLinked to original sources

Sickness and satiety: physiological mechanisms underlying perceptions of nausea and stomach fullness.

The pathophysiology of nausea and the physiological mechanisms underlying perceptions of stomach emptiness and fullness are not clearly understood, but several potentially important factors have been identified. Gastric dysrhythmias are believed to contribute to the subjective experience of nausea and may also be involved with perceptions of stomach emptiness, hunger, and even dyspepsia symptoms like bloating and early satiety. Normal gastric neuromuscular function is more evident in the absence of nausea and is also thought to be related to feelings of satiety or comfortable stomach fullness. Autonomic and endocrine influences may also play a critical role in the pathophysiology of nausea and abnormal perceptions of stomach emptiness or fullness. Achieving a better understanding of the gastric neuromuscular and neurohormonal influences on perceptions arising from the viscera may prove invaluable in the development of novel treatments for such conditions as unexplained nausea, functional dyspepsia, and obesity.

Autonomic Nervous System↗

Relationship between temporal changes in cardiac parasympathetic activity and motion sickness severity.

Chemotherapy-induced nausea has been associated with a time-related decrease in cardiac parasympathetic activity. We tested the hypothesis that a time-related decrease in cardiac parasympathetic activity would also be associated with nausea and other motion sickness symptoms during illusory self-motion (vection). Fifty-nine participants (aged 18-34 years: 25 male) were exposed to a rotating optokinetic drum to induce vection. Symptoms of motion sickness and an estimate of cardiac parasympathetic activity (respiratory sinus arrhythmia; RSA) were obtained at baseline and throughout a drum-rotation period. As expected, motion sickness symptoms increased and RSA decreased over time during drum rotation. Moreover, greater decreases in RSA over time correlated with greater motion sickness severity. These results suggest that a time-related decrease in cardiac parasympathetic activity may be an important correlate of nausea and motion sickness across different evocative contexts.

Adolescent↗

Spatial task performance, sex differences, and motion sickness susceptibility.

There are substantial individual differences in susceptibility to motion sickness, yet little is known about what mediates these differences. Spatial ability and sex have been suggested as possible factors in this relationship. 89 participants (57 women) were administered a Motion Sickness Questionnaire that assesses motion sickness susceptibility, a Water-level Task that gauges sensitivity to gravitational upright, and a Mental Rotation Task that tests an individual's awareness of how objects typically move in space. Significant sex differences were observed in performance of both the Water-level Task (p<.01), and the Mental Rotation Task (p<.005), with women performing less accurately than men. Women also had significantly higher scores on the Motion Sickness Questionnaire (p<.005). Among men, but not women, significant negative relationships were observed between Water-level Task performance and Motion Sickness Questionnaire score (p<.001) and between Mental Rotation Task performance and Motion Sickness Questionnaire score (p<.005). In conclusion, women performed significantly more poorly than men did on the spatial ability tasks and reported significantly more bouts of motion sickness. In addition, men showed a significant negative relationship between spatial ability and motion sickness susceptibility.

Adolescent↗

The effects of manipulating expectations through placebo and nocebo administration on gastric tachyarrhythmia and motion-induced nausea.

BACKGROUND: Interest in the role of expectation in the development of nausea and other adverse conditions has existed for decades. The purpose of this study was to examine the effects of manipulating expectations through the administration of placebos and nocebos on nausea and gastric tachyarrhythmia provoked by a rotating optokinetic drum. METHOD: Seventy-five participants were assigned to one of three groups. Positive-expectancy group participants were given placebo pills that would allegedly protect them against the development of nausea and motion sickness. Negative-expectancy group participants were given the same pills as nocebos; they were led to believe there was a tendency for them to make nausea somewhat worse. Placebo-control group participants were told the pills were indeed placebos that would have no effect whatsoever. RESULTS: Subjective symptoms of motion sickness were significantly lower among negative-expectancy group participants than positive-expectancy and placebo-control group participants (p<0.05). Gastric tachyarrhythmia, the abnormal stomach activity that frequently accompanies nausea, was also significantly lower among negative-expectancy group participants than positive-expectancy and Placebo-Control Group participants during drum rotation (p<.05) [corrected] CONCLUSIONS: Inducing negative expectations through nocebo administration reduced nausea and gastric dysrhythmia during exposure to provocative motion, whereas positive placebos were ineffective for preventing symptom development. That manipulation of expectation affected gastric physiological responses as well as reports of symptoms, suggests an unspecified psychophysiological mechanism was responsible for the observed group differences. These results also suggest that patients preparing for difficult medical procedures may benefit most from being provided with detailed information about how unpleasant their condition may become.

Adolescent↗