Biological psychology
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Biological psychology · Jul 2008
Stress-buffering effects of psychosocial resources on physiological and psychological stress response in pregnant women.
Sixty healthy pregnant women (aged 21-35 years), including 30 pregnant women at the beginning of second trimester and 30 women at the beginning of third trimester underwent a psychosocial stress test. Physiological (salivary free cortisol levels, salivary alpha-amylase levels) and psychological (perceived stress, mood, anxiety) responses to standardized psychosocial stress have been brought in association with psychosocial resources (self-efficacy and daily uplifts). Predictions revealed that higher resources predict lower physiological and psychological stress responses and higher mood levels. We conclude from our data that psychosocial resources appear to dampen psychological and physiological stress response during pregnancy.
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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.
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Biological psychology · Feb 2008
Randomized Controlled Trial Comparative StudyEffects of naltrexone on electrocutaneous pain in patients with hypertension compared to normotensive individuals.
An opioid mechanism may help explain hypertensive hypoalgesia. A double-blind placebo-controlled design compared the effects of opioid blockade (naltrexone) and placebo on electrocutaneous pain threshold, pain tolerance, and retrospective McGill Pain Questionnaire ratings in 35 unmedicated patients with essential hypertension and 28 normotensive individuals. The hypertensives experienced less pain than normotensives during the assessment of their pain tolerance; however, this manifestation of hypertensive hypoalgesia was not moderated by naltrexone. These findings fail to support the hypothesis that essential hypertension is characterised by relative opioid insensitivity.