No abstract

Triggers of ischemia in patients with coronary artery disease during daily life include not only strenuous exercise, but also activities involving low levels of exertion, such as anger and smoking. Mental activities appear to be as potent as physical activities in triggering daily life ischemia. Coffee and alcohol consumption are related to ischemia only by virtue of their associations with smoking.

Variations in affect following d-amphetamine and placebo were examined in healthy young adults who subsequently preferred d-amphetamine (choosers; n = 61) or placebo (nonchoosers; n = 48) in a drug preference procedure. Affect was assessed before and 1, 3, and 6 hr after participants received the placebo and 10 mg d-amphetamine. Following amphetamine as compared with placebo, choosers' ratings increased on scales measuring energy, cognitive efficiency, and well-being, and decreased on scales measuring fatigue and sedation. Nonchoosers reported no effects, sedative effects, and dysphoric effects of amphetamine. Following placebo, ratings of energy, efficiency, and well-being decreased, and ratings of sedation increased in choosers but not in nonchoosers. Variations in affect following placebo and amphetamine may constitute markers of risk for drug use.

In attended novelty oddball tasks, rare nontarget stimuli can elicit two late positive ERP components: P3a and P300. In passive oddball tasks, P300 is not elicited by these stimuli. In passive tasks, however, P3a is accompanied by another positive component, termed eP3a, which may have evaded detection in attended oddball tasks because of its spatiotemporal overlap with P300. To address this, temporal-spatial principal components analysis was used to quantify ERPs recorded in attended three-tone and novelty oddball tasks. As expected, novel stimuli elicited both P3a and P300. The analysis also identified a third component, evident in novelty ERPs as an inflection on the leading edge of P3a. This component has the same antecedent conditions as P3a, but is earlier and more centrally distributed. Its spatiotemporal characteristics suggest that it may be the eP3a component recently described in passive oddball tasks.

Two studies assessed the circadian variation of cardiovascular responses to stress in healthy and coronary artery disease (CAD) populations. In within-subjects designs, stressors were administered to healthy male subjects and male CAD patients both in the morning and afternoon, and subjects were classified as either morning or evening types using the Morningness-Eveningness Questionnaire (Horne & Ostberg, 1976, International Journal of Chronobiology, 4, 97-110). No consistent circadian variation in blood pressure or heart rate responses was observed in the aggregate sample of either healthy subjects or CAD patients. However, there were significant interactions between circadian type and time of day. In both populations, morning subjects exhibited higher cardiovascular levels during the morning session, and evening subjects exhibited higher levels during the afternoon session. Analyses of cardiovascular reactivity revealed less consistent evidence for this interaction. Self-reports of stress revealed interactions between time of day and morningness/eveningness only in the CAD sample. In CAD patients, preliminary analysis of myocardial wall function, an index of myocardial ischemia, did not reveal a significant interaction between morningness/eveningness and time of day, perhaps due to small sample size. The presence of differing circadian patterns in stress response based on individual differences in morningness/eveningness is discussed in terms of its methodological implications for psychophysiological research and in terms of the role of stress as an acute trigger of CAD.