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ObjectiveAttention deficit disorder (ADHD) is commonly associated with inhibitory dysfunction contributing to typical behavioral symptoms like impulsivity or hyperactivity. However, some studies analyzing intraindividual variability (IIV) of reaction times in children with ADHD (cADHD) question a predominance of inhibitory deficits. IIV is a measure of the stability of information processing and provides evidence that longer reaction times (RT) in inhibitory tasks in cADHD are due to only a few prolonged responses which may indicate deficits in sustained attention rather than inhibitory dysfunction. We wanted to find out, whether a slowing in inhibitory functioning in adults with ADHD (aADHD) is due to isolated slow responses.MethodsComputing classical RT measures (mean RT, SD), ex-Gaussian parameters of IIV (which allow a better separation of reaction time (mu), variability (sigma) and abnormally slow responses (tau) than classical measures) as well as errors of omission and commission, we examined response inhibition in a well-established GoNogo task in a sample of aADHD subjects without medication and healthy controls matched for age, gender and education.ResultsWe did not find higher numbers of commission errors in aADHD, while the number of omissions was significantly increased compared with controls. In contrast to increased mean RT, the distributional parameter mu did not document a significant slowing in aADHD. However, subjects with aADHD were characterized by increased IIV throughout the entire RT distribution as indicated by the parameters sigma and tau as well as the SD of reaction time. Moreover, we found a significant correlation between tau and the number of omission errors.ConclusionsOur findings question a primacy of inhibitory deficits in aADHD and provide evidence for attentional dysfunction. The present findings may have theoretical implications for etiological models of ADHD as well as more practical implications for neuropsychological testing in aADHD.

Der Trail Making Test (TMT) ist ein international weit verbreitetes Verfahren, das z. B. zur Untersuchung von Patienten mit erworbenen Hirnschädigungen eingesetzt wird. Die Performanz im TMT wird mit unterschiedlichen neuropsychologischen Domänen, wie z. B. Aufmerksamkeit und Exekutivfunktionen, in Verbindung gebracht. Trotz der häufigen Anwendung im klinischen Alltag liegen bisher keine deutschsprachigen Normen für einen umfassenden Altersrange vor. Die vorliegende Untersuchung hat daher den Einfluss von Alter und Bildung auf die Bearbeitungszeit im TMT bei deutschsprachigen Erwachsenen im Alter zwischen 18 und 85 Jahren erfasst und analysiert. Ausschlusskriterien bildeten neurologische oder psychiatrische Erkrankungen, die Beeinträchtigung des Blickfeldes bzw. der Sehfähigkeit, die motorische Beeinträchtigung der Arme und Hände sowie Drogen- oder Alkoholmissbrauch. Die Stichprobe ist in vier Altersgruppen aufgeteilt: 18 – 34 Jahre (n = 148), 35 – 49 Jahre (n = 111), 50 – 64 Jahre (n = 93) und 65 – 84 Jahre (n = 53). Hinsichtlich der Bildung wurden zwei Gruppen gebildet: niedriges bis mittleres Bildungsniveau ( ≤ 12 Jahre formale Bildung) und höheres Bildungsniveau ( ≥ 12 Jahre formale Bildung). Signifikante Korrelationen zwischen den demografischen Variablen und den Bearbeitungszeiten im TMT-A bzw. TMT-B zeigen, dass sowohl Alter als auch Bildung mit der Leistung im TMT korrelieren (p < .01). Post hoc Analysen machen deutlich, dass sich dabei alle Altersgruppen voneinander unterscheiden. Die Ergebnisse für die Bearbeitungszeit stehen in Einklang mit früheren Normierungsstudien, die ebenfalls Alter und Bildung als die bedeutsamsten Moderatoren für die Leistung im TMT identifiziert hatten.

Planning ahead the consequences of future actions is a prototypical executive function. In clinical and experimental neuropsychology, disc-transfer tasks like the Tower of London (TOL) are commonly used for the assessment of planning ability. Previous psychometric evaluations have, however, yielded a poor reliability of measuring planning performance with the TOL. Based on theory-grounded task analyses and a systematic problem selection, the computerized TOL-Freiburg version (TOL-F) was developed to improve the task's psychometric properties for diagnostic applications. Here, we report reliability estimates for the TOL-F from two large samples collected in Mainz, Germany (n = 3,770; 40-80 years) and in Vienna, Austria (n = 830; 16-84 years). Results show that planning accuracy on the TOL-F possesses an adequate internal consistency and split-half reliability (>0.7) that are stable across the adult life span while the TOL-F covers a broad range of graded difficulty even in healthy adults, making it suitable for both research and clinical application.

M-fluctuation tests are a recently proposed method for detecting differential item functioning in Rasch models. This article discusses a generalization of this method to two additional item response theory models: the two-parametric logistic model and the three-parametric logistic model with a common guessing parameter. The Type I error rate and the power of this method were evaluated by a variety of simulation studies. The results suggest that the new method allows the detection of various forms of differential item functioning in these models, which also includes differential discrimination and differential guessing effects. It is also robust against moderate violations of several assumptions made in the item parameter estimation.

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Local independence is a central assumption of commonly used item response theory models. Violations of this assumption are usually tested using test statistics based on item pairs. This study presents two quasi-exact tests based on the [Formula: see text] statistic for testing the hypothesis of local independence in the Rasch model. The proposed tests do not require the estimation of item parameters and can also be applied to small data sets. The authors evaluate the tests with three simulation studies. Their results indicate that the quasi-exact tests hold their alpha level under the Rasch model and have higher power against different forms of local dependence than several alternative parametric and nonparametric model tests for local independence.

Sexual health severely decreases with age. For males older than 40 years, erectile dysfunction (ED) is the most common sexual disorder. Although physical and psychological risk factors for ED have been identified, protective factors are yet to be determined. To date, no study has examined endocrine and psychosocial factors in parallel with regard to their modifying effect on the age-related increase in ED. Two hundred and seventy-one self-reporting healthy men aged between 40 and 75 years provided both psychometric data on sexual function and a set of potential psychosocial protective factors, and saliva samples for the analysis of steroid hormones and proinflammatory cytokines. Around 35% of the participants reported at least a mild form of ED. Direct associations with ED were identified for perceived general health, emotional support, relationship quality, intimacy motivation but not for steroid hormones or proinflammatory markers. Moderation analyses for the association between age and ED revealed positive effects for testosterone (T), dehydroepiandrosterone (DHEA), perceived general health, emotional support, intimacy motivation, and a negative effect for interleukin-6 (all p < .05; f2 > .17). Group differences between older men with and without ED emerged for T, DHEA, and psychometric measures such as perceived general health, emotional support, satisfaction with life, and intimacy motivation (all p < .05; d > .3). Both psychosocial and endocrine parameters moderated the association between age and sexual health. Perceived general health, emotional support, intimacy motivation, and relationship quality emerged as psychosocial protective factors against ED. Higher T and DHEA and lower interleukin-6 levels also buffered against an age-related increase in ED.