Children "tune out" in response to the ambiguous communication style of powerless adults.

Changes in children's attentional engagement were assessed as a function of their exposure to "teachers" who differed in perceived power and the communication style that is associated with perceived power. In Study 1, "teachers" (women assigned to an instructional role) were selected on the basis of their perceived power; low-power women were more likely than high-power women to display communication ambiguity. Children responded to low-power women with low levels of (1) autonomic orienting (consistent with low attention) and (2) high errors on a cognitively demanding task (mental arithmetic). Attentional disengagement was found to be mediated by the ambiguous communication style of low-power adults. In Study 2, the "teacher" was a confederate who systematically varied the facial and vocal ambiguity of her instructions. Children showed the lowest levels of orienting and the highest level of errors when the "teacher" was ambiguous in both face and voice. Results were interpreted as showing that adult ambiguity (naturally occurring or experimentally produced) leads to reductions in children's attentional engagement.

Experimental evidence for stages of health behavior change: the precaution adoption process model applied to home radon testing.

Hypotheses generated by the precaution adoption process model, a stage model of health behavior, were tested in the context of home radon testing. The specific idea tested was that the barriers impeding progress toward protective action change from stage to stage. An intervention describing a high risk of radon problems in study area homes was designed to encourage homeowners in the model's undecided stage to decide to test, and a low-effort, how-to-test intervention was designed to encourage homeowners in the decided-to-act stage to order test kits. Interventions were delivered in a factorial design that created conditions matched or mismatched to the recipient's stage (N = 1,897). Both movement to a stage closer to testing and purchase of radon test kits were assessed. As predicted, the risk treatment was relatively more effective in getting undecided people to decide to test than in getting decided-to-act people to order a test. Also supporting predictions, the low-effort intervention proved relatively more effective in getting decided-to-act people to order tests than in getting undecided people to decide to test.

Relationship between cyclic guanosine 3':5'-monophosphate formation and relaxation of coronary arterial smooth muscle by glyceryl trinitrate, nitroprusside, nitrite and nitric oxide: effects of methylene blue and methemoglobin.

The purpose of the present study was to determine time course relationship between cyclic GMP accumulation and relaxation in bovine coronary artery and evaluate the effects of recently identified inhibitors, methylene blue and methemoglobin, on these relationships. Arterial strips were suspended in specially mounted tissue baths which permitted continuous recording of isometric tension until rapid freeze-clamping for subsequent determination of cyclic GMP levels by radioimmunoassay. Relaxation and cyclic GMP levels were measured in submaximally contracted strips at zero time (untreated) or 5-sec to 5-min intervals after exposure to 0.5 microliter of nitric oxide, 1 microM glyceryl trinitrate, 1 microM sodium nitroprusside of 1 mM sodium nitrite in the absence or presence of 10 mM methylene blue or 1 microM methemoglobin. Cyclic GMP accumulation preceded onset of relaxation elicited by nitric oxide and glyceryl trinitrate and temporally correlated with relaxation induced by sodium nitroprusside and sodium nitrite. Methylene blue simultaneously inhibited cyclic GMP accumulation and relaxation induced by all four relaxants. In contrast to methylene blue, methemoglobin abolished cyclic GMP accumulation and relaxation elicited by nitric oxide without altering responses to glyceryl trinitrate, sodium nitroprusside and sodium nitrite. These findings are consistent with and strongly support an involvement of cyclic GMP formation in vascular smooth muscle relaxation elicited by nitrogen oxide-containing vasodilators.