Biological psychology
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Biological psychology · Apr 2008
Controlled Clinical TrialEffects of isometric exercise on pain are mediated by blood pressure.
Sensitivity to pain is reduced during exercise. The underlying mechanism has yet to be established. One possibility is that a baroreceptor-related mechanism may contribute to this exercise-induced hypoalgesia phenomenon. ⋯ Blood pressure increased in proportion to the force of the contraction. Mediational analyses using analyses of covariance indicated that the reduction in pain with exercise was substantially accounted for by the magnitude of the blood pressure response. These findings are consistent with an arterial baroreceptor inhibition mechanism for exercise-induced hypoalgesia.
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Biological psychology · Apr 2008
Comparative StudyChronic stress, salivary cortisol, and alpha-amylase in children with asthma and healthy children.
The present study examined whether chronic stress is related to daily life levels of salivary alpha-amylase (sAA), a marker for sympathetic activity, and cortisol in healthy children versus children with asthma. Children's sAA and cortisol levels were measured repeatedly over 2 days. Chronic stress measures included interviews with children about chronic home life stress and interviews with parents about one marker of socioeconomic status, parental education. ⋯ In conclusion, chronically stressed children with asthma showed lower salivary alpha-amylase output, indicating lower sympathetic activity, and implying a possible mechanism for increased susceptibility to symptom exacerbations. In contrast, higher cortisol levels in healthy children with chronic stress may indicate, for example, an increased risk for infectious diseases. This dichotomy emphasizes the different biological effects of chronic stress depending on illness status.
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Biological psychology · Apr 2008
Distinct effects of attention and affect on pain perception and somatosensory evoked potentials.
The influence of affect and attention on sensory and affective pain as well as on somatosensory evoked potentials in response to painful and nonpainful electrical stimuli was investigated in a single experimental design. Affect was induced by pictures from the International Affective Picture System; attention was manipulated by asking participants to focus attention either on the pictures or on the electrical stimuli. Sensory and affective pain ratings were generally lower during exposure to positive compared to negative and neutral pictures. ⋯ The N150 was modulated by picture valence, the P260 by picture arousal. Furthermore, the P260 was modulated by attention with highest amplitudes with an attention focus on the stimulus intensity. This study provides neurophysiological evidence that attention and affect have distinct effects on pain processing.