Horse-race model simulations of the stop-signal procedure

In the stop-signal paradigm, subjects perform a standard two-choice reaction task in which, occasionally and unpredictably, a stop-signal is presented requiring the inhibition of the response to the choice signal. The stop-signal paradigm has been successfully applied to assess the ability to inhibit under a wide range of experimental conditions and in various populations. The current study presents a set of evidence-based guidelines for using the stop-signal paradigm. The evidence was derived from a series of simulations aimed at (a) examining the effects of experimental design features on inhibition indices, and (b) testing the assumptions of the horse-race model that underlies the stop-signal paradigm. The simulations indicate that, under most conditions, the latency, but not variability, of response inhibition can be reliably estimated.     

Self-Relevance of Performance, Task Difficulty, and Task Engagement Assessed as Cardiovascular Response

Two experiments examined task engagement, quantified as cardiovascular (CV) response, under conditions of high self-relevance of performance (i. e., when performance had strong implications for the individual's self-definition and self-esteem). Experiment 1 involved a 2 (self-relevance) × 2 (task difficulty) design and revealed, in accordance with predictions derived from Brehm's energization model, that self-relevance per se does not result in high engagement, but that high self-relevance bound up with high task difficulty does. Experiment 2 involved three difficulty conditions (very easy, moderate, very difficult) under highly self-relevant performance conditions and revealed a curvilinear difficulty/engagement relationship. In both studies CV responses were independent of feeling states.     

Post-stroke depression: Main phenomenological clusters and their relationships with clinical measures

Objectives: To investigate the principal psychopathological dimensions of post-stroke depression (PSD) through the assessment of the factorial structure of the Post-Stroke Depression Rating Scale (PSDRS). Methods: We enrolled ninety-eight subjects with PSD, who underwent the PSDRS, MMSE and Barthel Index. Information about demographic, clinical, and neuroanatomical factors was collected. Results: The factor analysis extracted three factors accounting for 63.4% of the total variance, and identified as: 1) "Depressive and Anxious Symptoms" (DAS); 2) "Lack of Emotional Control" (LEC); 3) "Reduced Motivation" (RM). On multivariate statistics, DAS severity was predicted by previous history of mood disorders and Barthel Index; LEC severity was predicted by Barthel Index; RM severity was predicted by age. Conclusions: The PSDRS displayed a reliable factor structure that agreed with previous interpretation of PSD. In particular, core depressive symptoms seem to be related to premorbid personality and functional status, whereas apathy/anhedonia may be connected to brain aging.     

“Don't let the group down”: Facets of instrumentality moderate the motivating effects of groups in a field experiment

The motivating effects of group work as compared with individual work are not restricted to the research laboratory but have recently been documented in existing groups performing meaningful tasks. Freestyle swimmers at the 2008 Olympics were shown to swim faster in relay groups than in the individual competitions when their contribution was highly instrumental for the relay group (i.e., indispensable) because of their serial position in the group. The present study replicated and extended this work, aggregating a larger sample from major sports events (N = 199 freestyle swimmers) that also allowed for a competitive test between the instrumentality approach and explanations based on differences in the starting procedures of relay and individual competitions. Consistent with expectancy value models of effort expenditure in groups, swimmers were faster in the relay groups as compared with individual competitions only when (i) a swimmer's performance was highly instrumental for the group's performance (i.e., later serial position in the relay) and (ii) the group's performance was highly instrumental for a positive group outcome (i.e., the relay group had a good chance of winning a medal). The data were not consistent with an explanation of performance differences merely as a result of different starting procedures. Copyright © 2012 John Wiley & Sons, Ltd.     

Grandiose Fantasies and Low Self-Esteem: An Experimental Study

Grandiose states of mind could be an ineffective way to cope with low self-esteem. In fact, it is possible that grandiose fantasies would tend to induce doubts about personal worth and decrease self-esteem. This study explored whether grandiose fantasies help to cope with low self-esteem. The self-reported occurrence and unpleasantness of intrusive thoughts regarding the sense of exclusion, humiliation, and low self-esteem in non-clinical individuals were assessed during self-induced grandiose fantasies and self-induced relaxation. The occurrence and unpleasantness of low self-esteem intrusions were significantly higher during grandiose fantasies, suggesting that grandiose fantasy is ineffective at combating low self-esteem.     

Lasting effects of alcohol: Subliminal alcohol cues,impairment expectancies,and math performance

Many people believe that drinking alcohol reduces cognitive performance, and prior research has shown such expectancy‐related impairment even when people merely thought that the (non‐alcoholic) drink they consumed contained alcohol. This study tested whether subliminal priming with alcohol‐related cues would similarly result in expectancy‐consistent cognitive performance decrements. Additionally, the moderating role of alcohol use was examined. After assessing participants' baseline math performance, participants were primed with alcohol‐related or neutral words and then completed a post‐treatment math task. Whereas impairment expectancies had no influence on math performance in control participants, expectancies predicted math performance for participants primed with alcohol‐related words. As hypothesized, expectancy‐consistent impairment in performance was only observed among high alcohol users. The current findings suggest that, in the presence of alcohol‐related cues in the environment, some people may perform less on cognitive tasks even in the absence of actual or assumed alcohol consumption and without being aware of it. Copyright © 2011 John Wiley & Sons, Ltd.     

Towards understanding pleasure at the misfortunes of others: the impact of self-evaluation threat on schadenfreude

In two experiments we demonstrated that a self-evaluation threat intensifies schadenfreude. Moreover, we showed that a self-evaluation threat predicts schadenfreude in both threat-related and threat-unrelated domains and when controlling for feelings of envy and dislike towards the target and evaluations of the misfortune in terms of deservingness. These findings indicate that another's misfortune may be pleasing because it satisfies people's concern for a positive self-view and a sense of self-worth.     

The two sides of competition: Competition‐induced effort and affect during intergroup versus interindividual competition

Competition strongly affects individual effort and performance for both individuals and groups. Especially in work settings, these effort gains might come at the cost of individual well‐being. The present study tested whether competition increases both effort (as indicated by task performance) and stress (in terms of cardiovascular reactivity and affective response), and whether this effect is further qualified by the type of competition (interindividual vs. intergroup), using a cognitive computer‐based task and a 2 (Group: Yes, No) × 2 (Competition: Yes, No) × 2 (Gender) factorial design (N= 147). All participants either worked as a representative of a group or as an individual, and were offered performance‐related incentives distributed in a lottery. In the competition conditions, participants were informed that they competed with someone else, and that only the winning person/team would take part in the lottery. Consistent with expectations, competition increased both individual effort and cardiovascular reactivity compared to non‐competitive work. Moreover, for female participants, intergroup competition triggered increased effort and more positive affect than interindividual competition. Aside from documenting costly side‐effects of competition in terms of stress, this study provides evidence for a stress‐related explanation of effort gains during intergroup competition as compared to interindividual competition.     

Consumer behaviour and the toilet: Research on expulsive and retentive personalities

During the last five decades, a number of studies have attempted to draw from psychoanalytic theory to examine the relationship between evacuation disorders and a person's character. According to Freud's original conceptualization, early or harsh toilet training leads children to develop an anal retentive personality, characterized by the tendency to control their bowels as well as their material possessions; by contrast, liberal toilet training leads children to develop an anal expulsive personality, characterized by the tendency to excessively relieve faeces, as well as be being careless, messy, and inclined to dispose of old products and buy new ones. Although toilet training may not be responsible, these sets of traits do cohere. To empirically examine these hypotheses, we studied the personality traits and consumption habits of people suffering from different bowel disorders. By means of semistructured interviews, we analysed the personality characteristics, sociodemographic backgrounds, and peculiar consumption habits of people suffering from constipation and diarrhoeic syndromes. The results show that constipated people tend to be obstinate, excessively concerned with hygiene, and inclined toward retaining possessions, whereas diarrhoeic people tend to be careless, disorganized, and disposed to share their possessions with others. We discuss the theoretical and practical implications of these results and indicate avenues for future research.