Lipid reactivity to stress: II. Biological and behavioral influences.

This study examined behavioral and physiological influences on lipid concentrations during acute and chronic stressors. One hundred men (n = 92) and women (n = 8) were tested during a chronic stressor and during 2 acute stressors. During chronic stress, diet, physical activity, exercise, and sleep were examined. During the acute stressors, catecholamines, cortisol, plasma volume, and cardiovascular responses were examined. None of the behavioral influences could explain the lipid response to chronic stress. Responses of the atherogenic lipids to acute stressors were not solely reflecting hemoconcentration of the plasma but were moderately correlated with cardiovascular, epinephrine, and cortisol reactivity. Diastolic blood pressure reactors to the acute stressors had larger lipid responses to the chronic stressor than did nonreactors. Elevations in blood lipids during stress are not artifacts and may be clinically significant.     

EVALUATION OF A BRIEF STIMULUS PREFERENCE ASSESSMENT

We evaluated the utility of a brief (5-min) stimulus preference assessment for individuals with developmental disabilities. Participants had noncontingent (free) access to an array of stimuli and could interact with any of the stimuli at any time. Stimuli were never withdrawn or withheld from the participants during a 5-min session. In Experiment 1, the brief preference assessment was conducted for 10 participants to identify differentially preferred stimuli, and reinforcer assessments were conducted to test the reinforcing efficacy of those stimuli identified as highly preferred. In Experiment 2, a comparison was conducted between the brief preference assessment and a commonly used paired-stimulus preference assessment. Collectively, results demonstrated that the brief preference assessment identified stimuli that functioned as reinforcers for a simple operant response, identified preferred stimuli that were differentially effective as reinforcers compared to nonpreferred stimuli, was associated with fewer problem behaviors, and required less time to complete than a commonly used paired-stimulus preference assessment.     

The effects of electroconvulsive shock on the action of a reinforcing stimulus

Three experiments sought to evaluate the effect of electroconvulsive shock on the action of a reinforcing stimulus. In all experiments behavior was maintained on a 2 min variable interval schedule for food reinforcement. Foot shock at the termination of a buzzer stimulus served as the reinforcing stimulus for conditioned suppression during the ensuing buzzer interval. Omission of foot shock at the termination of the buzzer stimulus was followed by normal responding (no conditioned suppression) during the next buzzer interval. In Exp I electroconvulsive shock followed foot shock at varying time intervals. In the first subsidiary experiment electroconvulsive shock followed an unreinforced buzzer stimulus at varying time intervals. In the second subsidiary experiment electroconvulsive shock followed foot shock at varying time intervals and an additional buzzer stimulus was sounded between the termination of foot shock and the onset of electroconvulsive shock. These three experiments demonstrated that electroconvulsive shock invariably abolished the effects of the reinforcing stimulus if it followed conditioning by no more than 10.0 sec and never had an effect if it followed conditioning by 12.5 sec or more; electroconvulsive shock was not acting as a reinforcing stimulus in this situation.     

Leadership, followership, and evolution: some lessons from the past

This article analyzes the topic of leadership from an evolutionary perspective and proposes three conclusions that are not part of mainstream theory. First, leading and following are strategies that evolved for solving social coordination problems in ancestral environments, including in particular the problems of group movement, intragroup peacekeeping, and intergroup competition. Second, the relationship between leaders and followers is inherently ambivalent because of the potential for exploitation of followers by leaders. Third, modern organizational structures are sometimes inconsistent with aspects of our evolved leadership psychology, which might explain the alienation and frustration of many citizens and employees. The authors draw several implications of this evolutionary analysis for leadership theory, research, and practice.     

Subtyping children and adolescents with loss of control eating by negative affect and dietary restraint

OBJECTIVE: Research suggests that subtyping adults with binge eating disorders by dietary restraint and negative affect predicts comorbid psychopathology, binge eating severity, and treatment outcome. Little research has explored the validity and clinical utility of subtyping youth along these dimensions. METHOD: Children (aged 8-18 years) reporting loss of control eating (n=159) were characterized based upon measures of dietary restraint and negative affect using cluster analysis, and then compared regarding disordered eating attitudes and behaviors, and parent-reported behavior problems. RESULTS: Robust subtypes characterized by dietary restraint (n=114; 71.7%) and dietary restraint/high negative affect (n=45; 28.3%) emerged. Compared to the former group, the dietary restraint/high negative affect subtype evidenced increased shape and weight concerns, more frequent binge eating episodes, and higher rates of parent-reported problems (all ps<0.05). CONCLUSION: Similar to findings from the adult literature, the presence of negative affect may mark a more severe variant of loss of control eating in youth. Future research should explore the impact of dietary restraint/negative affect subtypes on psychiatric functioning, body weight, and treatment outcome.     

Driven from distraction: how infants respond to parents' attempts to elicit and re-direct their attention

This experiment examined how parents' verbal and non-verbal behavioral cues cause infants to shift and share attention within environments where many objects compete for infants' attention. Fifteen- and 21-month-old infants played with toys while their parent periodically shifted attention to a distal object within a larger array. Parents' attention-shifts were indicated by a change in direction of gaze, a pointing gesture, and/or verbalizations. Verbalizations were either attention-eliciting or attention-directing. In some trials parents covered their eyes to occlude line-of-gaze. Both ages seldom followed simple gaze shifts, but frequently followed gaze with-points or gaze-with-directing verbalizations. Attention-eliciting verbalizations increased infants' looks to the parent. Gaze occlusion reduced infants' responses to directing verbalizations. Responses to eliciting verbalizations increased with age. Infant receptive vocabulary did not predict attention-sharing, even when parents named objects (i.e., directing verbalizations). Implications for development of attention-sharing, language and understanding of visual attention are discussed.     

Self-Efficacy,Decision-Making,and Stages of Change: An Integrative Model of Physical Exercise1

Exercise has important health benefits but a large proportion of the population is physically inactive. We examined the stages of readiness to exercise and their relationship to self-efficacy, the costs and benefits of exercising, and self-report of physical activity in a sample of Rhode Island worksites. Using a three-step model-building approach, exploratory principal components analyses were followed by an examination of the stages of change model with confirmatory structural equation modeling procedures. The model was then examined with longitudinal data. Confirmatory and longitudinal analyses showed an excellent tit between the model and the data. Results indicated that the costs and benefits of exercise and self-efficacy for exercise were related to physical activity only indirectly, through the mediation of stage of readiness to exercise. Structural modeling fit indices revealed that much of the variation and covariation in physical activity was explained by the model. There is the potential to enhance the impact of exercise interventions, by targeting them so as to address factors related to these different stages of readiness.     

Making Better Sense of Animal Disenhancement: A Reply to Henschke

In "Making Sense of Animal Disenhancement" Adam Henschke provides a framework for fully understanding and evaluating animal disenhancement. His conclusion is that animal disenhancement is neither morally nor pragmatically justified. In this paper I argue that Henschke misapplies his own framework for understanding disenhancement, resulting in a stronger conclusion than is justified. In diagnosing his misstep, I argue that the resources he has provided us, combined with my refinements, result in two new avenues for inquiry: an application of concepts from political theory to disenhancement, and an inquiry in to the mode of valuation that underlies industrial animal agriculture and disenhancement proposals.