Deliberate practice predicts performance over time in adolescent chess players and drop‐outs: A linear mixed models analysis

In this study, the longitudinal relation between deliberate practice and performance in chess was examined using a linear mixed models analysis. The practice activities and performance ratings of young elite chess players, who were either in, or had dropped out of the Dutch national chess training, were analysed since they had started playing chess seriously. The results revealed that deliberate practice (i.e. serious chess study alone and serious chess play) strongly contributed to chess performance. The influence of deliberate practice was not only observable in current performance, but also over chess players' careers. Moreover, although the drop‐outs' chess ratings developed more slowly over time, both the persistent and drop‐out chess players benefited to the same extent from investments in deliberate practice. Finally, the effect of gender on chess performance proved to be much smaller than the effect of deliberate practice. This study provides longitudinal support for the monotonic benefits assumption of deliberate practice, by showing that over chess players' careers, deliberate practice has a significant effect on performance, and to the same extent for chess players of different ultimate performance levels. The results of this study are not in line with critique raised against the deliberate practice theory that the factors deliberate practice and talent could be confounded.     

Reward-driven modulation of adaptive control: How prospective monetary gains interact with unpredictable control demands

Shifting attention is an effortful control process and incurs a cost on the cognitive system. Previous research suggests that rewards, such as monetary gains, will selectively enhance the ability to shift attention when this demand for control is explicitly cued. Here, we hypothesized that prospective monetary gains will selectively enhance the ability to shift attention even when control demand is unpredictable and not cued beforehand in a modality shift paradigm. In two experiments we found that target detection was indeed facilitated by reward signals when an unpredictable shift of attention was required. In these crossmodal trials the target stimulus was preceded by an unpredictive stimulus directing attention to the opposite modality (i.e., visual–auditory or auditory–visual). Importantly, there was no reward effect in ipsimodal trials (i.e., visual–visual or auditory–auditory). Furthermore, the absence of the latter effect could not be explained in terms of physical limits in speed of responding. Potential motivation of monetary rewards thus selectively translates into motivational intensity when control (i.e., switching) is demanded in unpredictable ways.     

Zebra finches and Dutch adults exhibit the same cue weighting bias in vowel perception

Vocal tract resonances, called formants, are the most important parameters in human speech production and perception. They encode linguistic meaning and have been shown to be perceived by a wide range of species. Songbirds are also sensitive to different formant patterns in human speech. They can categorize words differing only in their vowels based on the formant patterns independent of speaker identity in a way comparable to humans. These results indicate that speech perception mechanisms are more similar between songbirds and humans than realized before. One of the major questions regarding formant perception concerns the weighting of different formants in the speech signal (“acoustic cue weighting”) and whether this process is unique to humans. Using an operant Go/NoGo design, we trained zebra finches to discriminate syllables, whose vowels differed in their first three formants. When subsequently tested with novel vowels, similar in either their first formant or their second and third formants to the familiar vowels, similarity in the higher formants was weighted much more strongly than similarity in the lower formant. Thus, zebra finches indeed exhibit a cue weighting bias. Interestingly, we also found that Dutch speakers when tested with the same paradigm exhibit the same cue weighting bias. This, together with earlier findings, supports the hypothesis that human speech evolution might have exploited general properties of the vertebrate auditory system.     

Randomized controlled trial on the effectiveness of metacognitive therapy and intolerance-of-uncertainty therapy for generalized anxiety disorder

This randomized controlled trial compared the effectiveness of metacognitive therapy (MCT) and intolerance-of-uncertainty therapy (IUT) for generalized anxiety disorder (GAD) in an outpatient context. Patients with GAD (N = 126) consecutively referred to an outpatient treatment center for anxiety disorder were randomly allocated to MCT, IUT, or a delayed treatment (DT) condition. Patients were treated individually for up to 14 sessions. Assessments were conducted before treatment (pretreatment), after the last treatment session (posttreatment), and six months after treatment had ended (follow-up). At posttreatment and follow-up assessments, substantial improvements were observed in both treatment conditions across all outcome variables. Both MCT and IUT, but not DT, produced significant reductions in GAD-specific symptoms with large effect sizes (ranging between 0.94 and 2.39) and high proportions of clinically significant change (ranging between 77% and 95%) on various outcome measures, and the vast majority of the patients (i.e., 91% in the MCT group, and 80% in the IUT group) no longer fulfilled the diagnostic criteria for GAD. Results further indicate that MCT produced better results than IUT. This was evident on most outcome measures, and also reflected in effect sizes and degree of clinical response and recovery.     

Development and Psychometric Evaluation of the Utrecht Grief Rumination Scale

Two different types of ruminative coping, depressive rumination and grief rumination, negatively influence bereavement outcome. Although grief-specific rumination is likely to be relevant in the bereavement context no internationally validated scale to measure grief rumination exists. Therefore, the current contribution aims to validate the Utrecht Grief Rumination Scale (UGRS), a scale developed to measure grief-specific rumination, in an English sample. Psychometric properties of the English UGRS were compared with those in a Dutch sample. 204 British adults (89 % women, 11 % men), bereaved on average 16 months ago, and 316 Dutch adults (88 % women, 12 % men), bereaved on average 12 months ago, filled out online questionnaires. Different types of rumination (grief rumination, brooding, reflection, trait rumination) and symptoms of psychopathology (anxiety, depression, complicated grief) were measured. A correlated five factor model provided the best fit for the UGRS. Multi-group comparisons showed that the factor structures of the English and Dutch version of the UGRS were highly similar across language groups. The UGRS showed excellent reliability. Results further supported the construct, convergent, divergent and concurrent validity of the English UGRS. The psychometric properties of the Dutch UGRS corroborated these findings. The UGRS appears a valid instrument to assess grief-specific rumination in international research and may have potential applicability as a clinical instrument to assess rumination in individuals with problematic grief.     

Payment by Results Systems: A Review of Research 1945–1985

Le taux d'utilisation des systemés de Payment by results (PBR) varie considerablement selon les pays, aussi bien en Europe de l'ouest que de Test. Les donnees disponibles laissent entendre que les pays de Test appliquent le PBR a la plupart de leurs travailleurs. Parmi les pays de l'ouest, l'lrlande et le Royaume Uni se placent a un niveau eleve, tandis que les Pays-Bas sont en queue de liste. II est surprenant que des bilans des recherches sur l'efficacite comparee du PBR et des systemés de salaire fixe ne soient pas disponibles. Dans notre travail, les donnees sont dans la mesure du possible presentees par systemés distincts a partir desquels on discute les recherches portant sur l'efficacite relative du PBR. Le merit rating est decevant. Le Scanlon Plan donne des résultats encourageants. Toutefois, la plupart des donnees interdis-ent d'inferer avec certitude sur les relations causales. On insiste sur quelques-uns des domaines que la recherche se doit d'explorer et sur les conditions favorisant I'elaboration et le choix de strategies pertinentes de remuneration.