The Effect of Paired Muscle Stimulation on Preparation for Movement

Paired muscle stimulation is used clinically to facilitate the performance of motor tasks for individuals with motor dysfunction. However, the optimal temporal relationship between stimuli for enhancing movement remains unknown. We hypothesized that synchronous, muscle stimulation would increase the extent to which stimulated muscles are concurrently prepared for movement. We validated a measure of muscle-specific changes in corticomotor excitability prior to movement. We used this measure to examine the preparation of the first dorsal interosseous (FDI), abductor digiti minimi (ADM), abductor pollicis brevis (APB) muscles prior to voluntary muscle contractions before and after paired muscle stimulation at four interstimulus intervals (0, 5, 10, and 75 ms). Paired muscle stimulation increased premovement excitability in the stimulated FDI, but not in the ADM muscle. Interstimulus interval was not a significant factor in determining efficacy of the protocol. Paired stimulation, therefore, did not result in a functional association being formed between the stimulated muscles. Somatosensory potentials evoked by the muscle stimuli were small compared to those commonly elicited by stimulation of peripheral nerves, suggesting that the lack of functional association formation between muscles may be due to the small magnitude of afferent volleys from the stimulated muscles, particularly the ADM, reaching the cortex.     

A cluster analysis of text message users based on their demand for text messaging: A behavioral economic approach

The goal of this study was to determine whether cluster analysis could be used to identify distinct subgroups of text message users based on behavioral economic indices of demand for text messaging. Cluster analysis is an analytic technique that attempts to categorize cases based on similarities across selected variables. Participants completed a questionnaire about mobile phone usage and a hypothetical texting demand task in which they indicated their likelihood of paying an extra charge to continue to send text messages. A hierarchical cluster analysis was conducted on behavioral economic indices, such as demand intensity, demand elasticity, breakpoint, and the maximum expenditure. With the cluster analysis, we identified 3 subgroups of text message users. The groups were characterized by (a) high intensity and low elasticity, (b) high intensity and medium elasticity, and (c) low intensity and high elasticity. In a demonstration of convergent validity, there were statistically significant and conceptually meaningful differences across the subgroups in various measures of mobile phone use and text messaging. Cluster analysis is a useful tool for identifying and profiling distinct, practically meaningful groups based on behavioral indices and could provide a framework for targeting interventions more efficiently.     

The demon that makes us go mental: mentalism defended

Philosophical Studies - Facts about justification are not brute facts. They are epistemic facts that depend upon more fundamental non-epistemic facts. Internalists about justification often argue...     

On Different Sides: Investigating the Persuasive Effects of Anger Expression in Political News Messages

Anger expression is increasingly prevalent in political news messages. However, the persuasive effects of expressing anger in a political context have received scant attention from researchers. We conducted two experiments to investigate the hypothesis that anger expression is detrimental to persuasion because it runs counter to well‐established social norms for the polite expression of opinions. We created political news messages including a persuasive appeal by a politician that was supported either with an expression of anger or with an expression of nonemotional disagreement. The results of Experiment 1 (N = 120) showed that anger messages were perceived as less appropriate than control messages, and that politicians expressing anger were perceived as less likable and less competent than politicians who disagreed in nonemotional terms. In Experiment 2 (N = 1,005), the negative effects of anger expression on perceived likability and competence were replicated. Also in line with Experiment 1, anger messages were perceived as less appropriate, but this time only for those with negative a priori attitudes toward the advocated position. In contrast, those with positive a priori positions toward the advocated position perceived anger messages as more appropriate than the control messages.     

Cognitive reappraisal attenuates the association between depressive symptoms and emotional response to stress during adolescence

Depression is associated with increased emotional response to stress. This is especially the case during the developmental period of adolescence. Cognitive reappraisal is an effective emotion regulation strategy that has been shown to reduce the impact of emotional response on psychopathology. However, less is known about whether cognitive reappraisal impacts the relationship between depressive symptoms and emotional responses, and whether its effects are specific to emotional reactivity or emotional recovery. The current study examined whether cognitive reappraisal moderated the relationship between depressive symptoms and trait or state measures of emotional reactivity and recovery. A community sample of 127 adolescents (M-age?=?15.28; 49% female, 47% Caucasian), at an age of risk for depression, completed self-report measures of trait emotional responding and depressive symptoms. In addition, they completed an in vivo social stress task and were assessed on state emotional reactivity and recovery from the stressor. Findings suggested that cognitive reappraisal was associated with an attenuated impact of depressive symptoms on trait and state emotional recovery. These results provide evidence that cognitive reappraisal may be an effective strategy for improving some aspects of emotional responding in relation to depressive symptoms among adolescents.     

Comorbidity of Pediatric Obsessive–Compulsive Disorder and Anxiety Disorders: Impact on Symptom Severity and Impairment

This study explored the impact of comorbidity on symptom severity and treatment outcome in a sample of 75 pediatric Obsessive–Compulsive Disorder (OCD) patients. Forty received cognitive–behavioral therapy (CBT). Overall, 56% had a comorbid disorder. Results revealed that youth with comorbid disorders (anxiety or otherwise) endorsed significantly more anxiety symptoms than youth with OCD only. Youth with comorbidities instead of or in addition to anxiety exhibited more severe OCD symptoms than youth with OCD alone or an anxiety-only comorbidity. Youth in the comorbidities instead of or in addition to anxiety group had the poorest CBT response relative to the other groups. These results suggest that relative to those with OCD alone or with an anxiety disorder comorbidity, youth with comorbidities instead of or in addition to anxiety have a differing clinical presentation (e.g., more severe symptoms) and worse psychotherapy outcome.

Perfectionism, and Cognitions, Affect, Self-esteem, and Physiological Reactions in a Performance Situation

The current paper describes the results of an experiment in which 200 students who varied in levels of trait perfectionism performed a laboratory task and then were assessed in terms of levels of state affect, state self-esteem, and state automatic thoughts. Independent variables included task difficulty (high versus moderate level of difficulty) and performance feedback independent of their actual level of performance (positive or negative). Analyses also examined objective levels of performance (i.e., the number of errors on the task) and initial confidence in performance. Analyses showed that the experience of state automatic thoughts involving perfectionism was associated with negative automatic thoughts, negative affective reactions, and lower state self-esteem. Analyses of changes in mood and self-esteem showed generally that participants high in socially prescribed perfectionism had increased levels of dysphoria and anxiety and lower levels of state self-esteem following the experience of negative performance feedback or after having a relatively poor performance. Analyses of the physiological measures found increased systolic blood pressure among self-oriented perfectionists who had poorer performance and among socially prescribed perfectionists who had received negative feedback about their performance. The results for heart-rate changes yielded a less clear pattern, though there was evidence that participants with high socially prescribed perfectionism had increased heart rate if they received negative feedback and were relatively low in confidence. Collectively, these findings illustrate that how perfectionists react in challenging situations varies as a function of actual performance, performance feedback, and feelings of personal efficacy.

What is it to “B” a relation?

The purpose of this paper is two fold: first, I look to show Oaklander’s (The ontology of time. New York: Prometheus Books, 2004) theory of time to be false. Second, I show that the only way to salvage the B-theory is via the adopting of the causal theory of time, and allying this to Oaklander’s claim that tense is to be eliminated. I then raise some concerns with the causal theory of time. My conclusion is that, if one adopts eternalism, the unreality of time looks a better option than the B-theory. With thanks to Robin Le Poidevin, Robbie Williams, Andrew McGonigal, Peter Simons, Chris Timpson and an anonymous referee for this journal for comments on a previous draft.