Contextual conditioning and reinstatement of extinguished instrumental responding

In three experiments we studied the relationship between contextual conditioning and the reinstatement of extinguished lever pressing that occurs when noncontingent food is introduced following extinction. In all three experiments the non-contingent food was presented off-baseline (with the response levers not present). On subsequent tests, with the response levers present, animals that had been exposed to food showed more reinstatement of lever pressing than control animals. This finding rules out alternative mechanisms for the reinstated responding that rely on the interaction of non-contingent food and responding, such as superstitious reinforcement or the discriminative after-effects of food. In addition, in each experiment we demonstrated that manipulations known to affect contextual conditioning (signalling the food in Experiment 1, context extinction in Experiment 2, and switching contexts in Experiment 3) reduced the reinstatement. These results are consistent with the claim that contextual conditioning is important in controlling instrumental conditioning and closely parallel findings concerning the reinstatement of Pavlovian responsing following extinction.     

Identifying subgroups that succeed or fail with three levels of physical activity intervention: the Activity Counseling Trial.

The authors used recursive partitioning methods to identify combinations of baseline characteristics that predict 2-year physical activity success in each of 3 physical activity interventions delivered in the multisite Activity Counseling Trial. The sample consisted of 874 initially sedentary primary care patients, ages 35-75 years, who were at risk for cardiovascular disease. Predictors of 2-year success were specific to each intervention and represented a range of domains, including physiological, demographic, psychosocial, health-related, and environmental variables. The results indicate how specific patient subgroups (e.g., obese, unfit individuals; high-income individuals in stable health) may respond differently to varying levels and amounts of professional assistance and support. The methods used provide a practical first step toward identifying clinically meaningful patient subgroups for further systematic investigation.     

The role of illness uncertainty on coping with fibromyalgia symptoms.

This study examined the role of illness uncertainty in pain coping among women with fibromyalgia (FM), a chronic pain condition of unknown origin. Fifty-one FM participants completed initial demographic and illness uncertainty questionnaires and underwent 10-12 weekly interviews regarding pain, coping difficulty, and coping efficacy. Main outcome measures included weekly levels of difficulty coping with FM symptoms and coping efficacy. Multilevel analyses indicated that pain elevations for those high in illness uncertainty predicted increases in coping difficulty. Furthermore, when participants had more difficulty coping, they reported lower levels of coping efficacy. Results were consistent with hypothesized effects. Illness uncertainty accompanied by episodic pain negatively influenced coping efficacy, an important resource in adaptation to FM.     

The impact of informant gender on children’s endorsement of scientific and non-scientific information

By roughly 6 years of age, children acquire the stereotype that men are more competent than women in science, technology, engineering, and mathematics (STEM), potentially leading to greater trust in scientific information provided by men. This study tested whether 3- to 8-year-old children differentially endorsed conflicting information about science and toys presented by male and female informants depicted as a ‘man’ and ‘woman’ (Exp1) or ‘scientists’ (Exp2). Children were expected to endorse toy testimony from gender-matched informants; thus, the key question concerned endorsement of science testimony. In Exp1 (N = 149), boys and girls showed a same-gender informant preference for toy testimony; however, girls endorsed the male informant's testimony more for science than for toys – but only when tested by a male experimenter. In Exp2 (N = 264), boys and girls showed a same-gender preference, irrespective of content. Findings suggest that STEM-related gender stereotypes might lead girls to trust scientific information presented by men over women in certain contexts.