Learn More
It is well established that performance is influenced by pressure, but the underlying mechanisms of the pressure-performance relationship are poorly understood. To address this important issue, the current experiment evaluated psychological, physiological, and kinematic factors as mediators of the pressure-performance relationship. Psychological,(More)
A baroreflex mechanism may explain hypertensive hypoalgesia. At rest, arterial baroreceptors are stimulated during the systolic upstroke of the pressure pulse wave. This study examined the effects of naturally occurring variations in baroreceptor activity during the cardiac cycle on an objective measure of pain, the nociceptive flexion reflex (NFR). Two(More)
In 2 experiments, the effects of mental stress on limb stiffness were investigated. The relative contribution to arm stiffness of individual muscle activity, co-contraction, muscle reflexes, and postural adjustments were examined. In each experiment, participants (N = 24, Experiment 1; N = 16, Experiment 2) held their supinated hand under a tray that they(More)
Hypertension is characterized by cognitive deficits. As evidence for impaired psychomotor speed, including slower reaction times, is mixed, we aimed to provide a detailed investigation of simple reaction time in hypertension. Pre-motor and motor reaction times were measured across the cardiac cycle in 30 hypertensives and 29 normotensives to determine the(More)
Carotid baroreceptor stimulation has been shown to dampen pain. This study tested, in 40 normotensive adults, the hypothesis that pain is lower during systole when arterial baroreceptor stimulation is maximal than diastole when stimulation is minimal. The sural nerve was stimulated electrocutaneously to obtain a nociceptive flexion reflex (NFR) threshold,(More)
Although it is well established that performance is influenced by competitive pressure, our understanding of the mechanisms which underlie the pressure-performance relationship is limited. The current experiment examined mediators of the relationship between competitive pressure and motor skill performance of experts. Psychological, physiological, and(More)
Slowing and loss of muscle power are major factors limiting physical performance but little is known about the molecular mechanisms involved. The slowing might be a consequence of slow detachment of cross bridges and, if this were the case, then a reduction in the ATP cost of an isometric contraction would be expected as the muscle fatigued. The human(More)
Catastrophizing is reliably associated with increased reports of clinical and experimental pain. To test the hypothesis that catastrophizing may heighten pain experience by increasing nociceptive transmission through spinal gating mechanisms, the present study examined catastrophizing as a predictor of pain ratings and nociceptive flexion reflex (NFR)(More)
PURPOSE To investigate the relationship between vascular function parameters measured at the retinal and systemic level and known markers for cardiovascular risk in patients with impaired glucose tolerance (IGT). METHODS Sixty age- and sex-matched white European adults (30 with IGT and 30 with normal glucose tolerance [NGT]) were recruited for the study.(More)
It has been suggested that the reduced fatigability of muscles exercised at short length may result from a decrease in the metabolic cost of contractions in the shortened position. We compared the fatigue properties and metabolic cost of stimulated isometric tetanic contractions in the tibialis anterior of 10 normal subjects at the optimum length (Lo) for(More)