Stimulus control of habits: Evidence for both stimulus specificity and devaluation insensitivity in a dual-response task

Goal-directed and habitual actions are clearly defined by their associative relations. Whereas goal-directed control can be confirmed via tests of outcome devaluation and contingency-degradation sensitivity, a comparable criterion for positively detecting habits has not been established. To confirm habitual responding, a test of control by the stimulus–response association is required while also ruling out goal-directed control. Here we describe an approach to developing such a test in rats using two discriminative stimuli that set the occasion for two different responses that then earn the same outcome. Performance was insensitive to outcome devaluation and showed stimulus–response specificity, indicative of stimulus-controlled behavior. The reliance of stimulus–response associations was further supported by a lack of sensitivity during the single extinction test session used here. These results demonstrate that two concurrently trained responses can come under habitual control when they share a common outcome. By reducing the ability of one stimulus to signal its corresponding response–outcome association, we found evidence for goal-directed control that can be dissociated from habits. Overall, these experiments provide evidence that tests assessing specific stimulus–response associations can be used to investigate habits.     

Effects of a single bout of moderate-to-vigorous physical activity on executive functions in children with attention-deficit/hyperactivity disorder: A systematic review and meta-analysis

ObjectivesThe aim of this study was to systematically review the literature investigating the acute effects of moderate-to-vigorous physical activity (MVPA) on executive functions (EFs) in children with attention-deficit/hyperactivity disorder (ADHD) and perform a meta-analysis of the effects of MVPA on task components that require lower and higher EF demand in this population.MethodsThe systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Six electronic databases, i.e., PubMed, Scopus, Web of Science, Embase, SPORTDiscus, and Education Resources Information Center (ERIC), were searched for eligible studies. Random-effects weights were used to pool the effect sizes. Publication bias was assessed by Egger’s regression test and Rosenthal’s fail-safe N. This study is registered on PROSPERO, number CRD42020184082.ResultsThe electronic database search yielded 12 studies, which met the inclusion criteria, comprising a total of 375 participants. Eleven studies with data from 275 participants were included in the meta-analysis to examine the acute effects of MVPA on tasks with lower and higher EF demand. A single bout of MVPA had a small positive effect on tasks with lower (n = 10, g = 0.32, 95% CI = 0.123–0.517) and higher (n = 10, g = 0.25, 95% CI = 0.13–0.371) EF demand. No publication bias was found.ConclusionsA single bout of MVPA may have a general facilitative effect on cognition, indicating that acute MVPA may be a transient nonpharmacological adjunctive treatment for childhood ADHD.     

Does Exercising with Another Enhance the Stress-Reducing Benefits of Exercise?

This study sought to determine if the stress-reducing benefits of exercise are improved by exercising with others rather than alone. One hundred and thirty-six participants completed a series of questionnaires measuring levels of tension, calmness, energy, and tiredness before exercise, immediately following exercise, and later that day before bedtime. Participants exercised on a laboratory stationary bicycle for 30 minutes at moderate intensity either alone, with another person while talking, or with another person while remaining silent. A series of ANOVA procedures revealed that participants generally experienced more energy and calmness and less tiredness after exercise. Furthermore, exercising with someone resulted in more calmness but also more tiredness than when exercising alone. Males generally reported more positive psychological effects than females. Results suggest that exercise with someone may be calming but more tiring due to a potential increased competition or workload.     

The Impact of Exercise on Hormones Is Related to Autonomic Reactivity to a Mental Task

This study examined the effects of an acute physical stressor on salivary testosterone (Tsal) and cortisol (Csal) and their relationship with the autonomic responsiveness to a mental task in fit young men (n = 30). Salivary testosterone (Tsal) and cortisol (Csal) levels were determined before and after a maximal bicycle exercise. Heart rate (HR) and skin conductance levels (SCL) were continuously recorded before, during, and after a Stroop task. Tsal and Csal levels diminished while HR and SCL increased in response to stressors in all the sample. When subjects were distributed in function of their endocrine response to the physical stressor, high Tsal responders showed higher HR reactivity than low responders, and high Csal responders showed higher SCL reactivity and lower reaction time in the Stroop task. These results show that the influence of an acute physical stressor on hormones is associated with the autonomic responses to a mental task.     

Evaluating the duration of the competing response in habit reversal: a parametric analysis.

The effectiveness of habit reversal was compared across three different competing response (CR) durations. Results showed that 1‐min and 3‐min CR durations were associated with short‐term and long‐term increases in nail length for people who bit their nails. A 5‐s CR duration produced immediate increases in nail length that were not maintained. Social validity data were consistent with these findings.     

Sociocultural correlates of compulsive exercise: is the environment important in fostering a compulsivity towards exercise among adolescents?

Sociocultural factors hypothesised to be influential in eating disorders were assessed for their relationship with compulsive exercise. A sample of 828 adolescent boys and girls completed measures assessing sociocultural messages to change body shape as well as pressure to be thin, and also measures of compulsive exercise and disordered eating. Results showed that the sociocultural influences differed slightly between boys and girls. Hierarchical regressions showed that, after controlling for disordered eating and BMI, messages to become more muscular and media pressure to be thin significantly predicted compulsive exercise in boys, while the same regression in girls reported only media pressure to be thin as a significant predictor of compulsive exercise. These findings demonstrate the influence of the media in boys’ and girls’ compulsive exercising, as well as highlight the influence of body shape messages to become more muscular on boys’ compulsive exercise.     

Views on aging and emotional benefits of physical activity: Effects of an exercise intervention in older women

Objectives

This intervention study evaluated the effects of exercise in old age on views on one’s own aging and on direct approach motivation for physical activity. It further examined the mechanism between these variables.

Design

Two hundred forty-seven healthy women aged 70−93 years were randomized to an exercise course (n = 86), an active (n = 85), or a passive control group (n = 76) for a 6-month participation in Berlin, Germany. Activity interventions (3 × 1.5 h/wk) were conducted using standardized manuals.

Method

Group differences in changes of views on aging and direct approach were evaluated by analyses of covariance adjusted for baseline. A mediating effect of direct approach between exercise participation and views on aging was tested with percentile-based bootstrapping.

Results

In contrast to both the active and the passive control groups, higher direct approach, F(2, 226) = 6.97, p = .001, and less aging dissatisfaction, F(2, 225) = 5.39, p = .005, were observed in the exercise group after 6 months. Exercise had an indirect beneficial effect on aging dissatisfaction through direct approach, B = −0.31, 95% CI = −0.68 to −0.05.

Conclusion

In women above 70 years, exercise participation increases direct approach motivation which in turn leads to lower aging dissatisfaction. This shows that exercise holds the potential to overcome subjective ageist bias.     

Defining features of unhealthy exercise associated with disordered eating and eating disorder diagnoses

ObjectivesThe current study sought to compare different features of unhealthy exercise on associations with disordered eating and their ability to identify individuals with eating disorders. A secondary aim of the study was to compare prevalence and overlap of different aspects of unhealthy exercise and potential differences in their gender distribution.DesignCross-sectional epidemiological study.MethodsA community-based sample of men (n = 592) and women (n = 1468) completed surveys of health and eating patterns, including questions regarding exercise habits and eating disorder symptoms.ResultsCompulsive and compensatory features of exercise were the best predictors of disordered eating and eating disorder diagnoses compared to exercise that was excessive in quantity. Further, compulsive and compensatory aspects of unhealthy exercise represented overlapping, yet distinct qualities in both men and women.ConclusionsIncluding the compulsive quality among the defining features of unhealthy exercise may improve identification of eating disorders, particularly in men. Results suggest that the compensatory aspect of unhealthy exercise is not adequately captured by the compulsive aspect of unhealthy exercise. Thus, interventions that target unhealthy exercise behaviors among high-risk individuals, such as athletes, may benefit from addressing both the compulsive and compensatory aspects of unhealthy exercise. Future prospective longitudinal studies will aid in determining the direction of the association between these features of unhealthy exercise and the onset of eating pathology.     

Emphasizing appearance versus health outcomes in exercise: The influence of the instructor and participants’ reasons for exercise

The objectifying nature of exercise environments may prevent women from reaping psychological benefits of exercise. The present experiment manipulated self-objectification through an exercise class taught by an instructor who emphasized exercise as either a means of acquiring appearance or health outcomes. The purpose of this study was to test for interactions between the class emphasis and participants’ reasons for exercise (i.e., appearance, health) predicting participants’ state self-objectification, state social physique anxiety, exercise class enjoyment, and future intentions of returning to a similar exercise class. Results, obtained via pre- and post-exercise questionnaires, revealed a significant interaction between class emphasis and health reasons for exercise predicting state self-objectification. Participants with lower health reasons for exercise reported greater state self-objectification in the appearance-focused class compared to those with higher health reasons for exercise. Adopting stronger health reasons for exercise may buffer exercise participants from the more objectifying aspects of the group exercise environment.     

The effect of exercise and childbirth classes on fear of childbirth and locus of labor pain control

This study sought to track changes in intensity of fear of childbirth and locus of labor pain control in women attending an exercise program for pregnant women or traditional childbirth classes and to identify the predictors of these changes. The study was longitudinal/non-experimental in nature and run on 109 healthy primigravidae aged from 22 to 37, including 62 women participating in an exercise program for pregnant women and 47 women attending traditional childbirth classes. The following assessment tools were used: two scales developed by the present authors – the Fear of Childbirth Scale and the Control of Birth Pain Scale, three standardized psychological inventories for the big five personality traits (NEO Five Factors Inventory), trait anxiety (State–Trait Anxiety Inventory) and dispositional optimism (Life Oriented Test–Revised) and a questionnaire concerning socioeconomic status, health status, activities during pregnancy, relations with partners and expectations about childbirth. Fear of childbirth significantly decreased in women participating in the exercise program for pregnant women but not in women attending traditional childbirth classes. Several significant predictors of post-intervention fear of childbirth emerged: dispositional optimism and self-rated health (negative) and strength of the belief that childbirth pain depends on chance (positive).