Validierung eines elektrokortikalen Lateralisierungsmaßes für semantische Wortverarbeitung

Läsionsstudien und Studien unter Verwendung bildgebender Verfahren haben wiederholt die Linkslateralisierung semantischer Sprachverarbeitung im Gehirn gezeigt. Interessanterweise gibt es bisher kaum Studien unter Verwendung ereigniskorrelierter Potentiale (EKPs), die eine solche Lateralisierung semantischer Sprachverarbeitung nahelegen. Eine mögliche Erklärung hierfür könnte die Überlagerung sprachspezifischer und sprachunspezifischer EKP-Komponenten sein, die eine eindeutige Identifikation sprachbezogener lateralisierter Aktivität erschwert. Zur Herausarbeitung linkslateralisierter EKP-Aktivität wird ein neuer methodischer Ansatz vorgestellt und angewendet, bei dem ein Lateralisierungsmaß als die Differenz von linksseitiger abzüglich rechtsseitiger EKP-Aktivität berechnet wird. Im Rahmen von drei Studien zur semantischen Verarbeitung von Einzelwörtern wurde unter Zuhilfenahme dieses Ansatzes wiederholt eine temporoparietale Negativität mit einem Amplitudenmaximum bei 300 ms nach Wortbeginn gefunden. Die Komponente wies in Reaktion auf visuell präsentierte Wörter einen spezifischen Anstieg in einer semantischen Aufgabenbedingung im Vergleich zu zwei Kontrollbedingungen auf, die keine semantische Verarbeitung erforderten, und wurde dementsprechend als posteriore semantische Asymmetrie (PSA) benannt. Beobachtete Korrelationen zwischen dem bedeutungsspezifischen Anstieg der PSA und Maßen verbaler Intelligenz weisen auf die Sprachspezifität dieser Komponente hin. In zwei weiteren Studien trat die PSA bei ansonsten gleichen Aufgabenbedingungen nicht für Bilder und nicht für auditiv präsentierte Wörter auf, was als Evidenz für die Spezifität der PSA für die semantische Verarbeitung visueller Wörter angesehen wird. In zwei weiteren Studien wurde zum einen gezeigt, dass die PSA beim Erlernen von Wörtern deren Distinktheit im Lernkontext widerspiegelt. Zum anderen erwies sich das Lateralisierungsmaß auch für die Untersuchung prä-semantischer Sprachverarbeitungsprozesse visuellen Materials gegenüber klassischen unlateralisierten EKP-Komponenten als vorteilhaft. So war es mit dem Lateralisierungsmaß beispielsweise möglich, gleichzeitig Effekte von Aufmerksamkeit und Lexikalität abzubilden

Pro-criminal attitudes, intervention, and recidivism

We review the recent research literature on pro-criminal attitudes (PCAs) as dcausal factor of recidivism with a focus on studies on the effectiveness of offender treatment programs targeting PCAs to prevent recidivism. The main conclusions that can be derived from the literature are: (1) the evidence supports the hypothesis that PCAs are related to reoffending; (2) most investigated offender treatment programs tend to reduce PCAs, although the general lack of adequate control group designs does not rule out alternative explanations for this reduction; and (3) there is no conclusive empirical evidence that intervention programs designed to reduce PCAs are effective in reducing recidivism. Empirical research in this area lacks the theoretical and methodological rigor to test causal models of the influence of treatment on reducing PCAs, and effects of PCAs on recidivism. Limitations of the empirical evidence are related to inadequate research designs and/or suboptimal data analysis strategies. Recommendations concerning optimized research designs and data analysis strategies that are likely to provide more conclusive evidence on the relation of PCAs, PCA treatment, and recidivism are given. (C) 2013 Elsevier Ltd. All rights reserved

Multiple neural signatures of social proof and deviance during the observation of other people's preferences

Detecting one's agreement with or deviation from other people, a key principle of social cognition, relies on neurocognitive mechanisms involved in reward processing, mismatch detection, and attentional orienting. Previous studies have focused on explicit depictions of the (in) congruency of individual and group judgments. Here, we report data from a novel experimental paradigm in which participants first rated a set of images and were later simply confronted with other individuals' ostensible preferences. Participants strongly aligned their judgments in the direction of other people's deviation from their own initial rating, which was neither an effect of regression toward the mean nor of evaluative conditioning (Experiment 1). Most importantly, we provide neurophysiological evidence of the involvement of fundamental cognitive functions related to social comparison (Experiment 2), even though our paradigm did not overly boost this process. Mismatches, as compared to matches, of preferences were associated with an amplitude increase of a broadly distributed N400-like deflection, suggesting that social deviance is represented in the human brain in a similar way as conflicts or breaches of expectation. Also, both early (P2) and late (LPC) signatures of attentional selection were significantly modulated by the social (mis) match of preferences. Our data thus strengthen and valuably extend previous findings on the neurocognitive principles of social proof

Investigating nuisance effects induced in EEG during tACS application

Transcranial alternating-current stimulation (tACS) in the frequency range of 1–100 Hz has come to be used routinely in electroencephalogram (EEG) studies of brain function through entrainment of neuronal oscillations. It turned out, however, to be highly non-trivial to remove the strong stimulation signal, including its harmonic and non-harmonic distortions, as well as various induced higher-order artifacts from the EEG data recorded during the stimulation. In this paper, we discuss some of the problems encountered and present methodological approaches aimed at overcoming them. To illustrate the mechanisms of artifact induction and the proposed removal strategies, we use data obtained with the help of a schematic demonstrator setup as well as human-subject data

Testing Causal Explanations of Viewing Time Measures of Sexual Interests

The term viewing time (VT) effect refers to a phenomenon whereby respondents typically take longer to judge the sexual attractiveness of targets from sexually preferred (versus nonpreferred) categories. Although frequently characterized as an unobtrusive measure of respondents’ sexually motivated reactions to the stimulus images themselves, the typical pattern of response times might be sufficiently explained by the task demands of the seemingly less relevant rating task. Utilizing three different VT variants, the present paper reports an experimental investigation (N = 136 heterosexual women and men) that tested hypotheses derived from hot stimulus-based processes versus cold cognitive task-based processes. Specifically, stimulus-based processes would predict VT effects even without a rating task, greater VT effects for sexually more suggestive images, and correlations of VT effects with individual sex drive differences. The task-based processes would not imply such predictions, but instead suggest identical response patterns for abstract non-pictorial stimuli that require the same feature integration. Results unanimously speak to the relevance of task demands but provide no support for stimulus-based processes. Implications of these findings for the causal explanation of VT effects are discussed