Hierarchical Multinomial Processing Tree Models: A Latent-Trait Approach

Multinomial processing tree models are widely used in many areas of psychology. A hierarchical extension of the model class is proposed, using a multivariate normal distribution of person-level parameters with the mean and covariance matrix to be estimated from the data. The hierarchical model allows one to take variability between persons into account and to assess parameter correlations. The model is estimated using Bayesian methods with weakly informative hyperprior distribution and a Gibbs sampler based on two steps of data augmentation. Estimation, model checks, and hypotheses tests are discussed. The new method is illustrated using a real data set, and its performance is evaluated in a simulation study.     

Accuracy of confidence judgments: Stability and generality in the learning process and predictive validity for learning outcome

One aspect of metacognition is the monitoring of memory or comprehension measured with retrospective confidence judgments after test taking. The research questions of the present study were whether different measures for the accuracy of such confidence judgments are stable over learning time, whether they generalize over two different tests, and whether they predict the learning outcome. In order to answer these questions, a study was conducted in which university students (N = 113) learned about the basic concepts of operant conditioning for 30 min. Knowledge tests with confidence judgments presented after each item were obtained before learning, after 10 min, and at the end of the learning session. Bias and absolute bias were calculated as absolute measures of accuracy, and gamma, Pearson’s r, andd _a were calculated as relative measures of accuracy. The results showed that the absolute measures were stable, but that the relative measures were not. Furthermore, absolute bias, gamma, and Pearson’s r obtained 10 min after the beginning of the learning process predicted the learning outcome. The results are discussed with regard to research on different measures of accuracy for confidence judgments.     

The role of occlusion cues in apparent motion

Classical apparent motion stimuli exhibit an inherent ambiguity with respect to the onsets and offsets of the stimulus elements. Sigman and Rock (1974, Perception 3 9-28) presented evidence suggesting that occlusion cues are used to resolve this ambiguity. We present results from experiments designed to further test predictions of this hypothesis. As expected, we found that the apparent motion of a target stimulus is suppressed when a 'moving' occluder is positioned such that it rationalises the onsets and offsets of the stimulus elements constituting the target. Somewhat unexpectedly, though, we also observed a slight tendency for motion suppression under conditions where the target was only partially occluded. The expected motion suppression occurred both with solid occluders and purely virtual Kanizsa-like occluders, although it was not always observed in the latter case. Motion suppression was found to occur over a wide range of stimulus onset asynchronies. Finally, we used binocular disparity cues to test the occlusion account of the motion suppression phenomenon against an alternative explanation in terms of attentional factors. The results are in clear favour of the occlusion account.     

Ressourcenaktivierung bei Patienten

Background

Starting from Klaus Grawe’s draft of a general psychotherapy, the patient’s resources and resource-activating interventions have received increasing attention in empirical research.

Objective

The effectiveness of standardized writing instructions for the activation of patients’ resources before participating in internet chat aftercare groups for psychosomatic patients was examined.

Method

In a randomized controlled trial writing instruction for the activation of patients’ resources was given in 52 out of 102 internet chat aftercare sessions. The effects of this minimal intervention on the patients’ activity and the number of positive emotion words expressed during the chat session were examined. Additionally, the effects on patients’ self-esteem, attachment, orientation, control and well-being after the group sessions were assessed.

Results

Patients reported higher levels of self-esteem, orientation, control and well-being after chat sessions with a resource-activating intervention. No differences between intervention and control groups were detected on the text-based variables activity and number of positive emotion words.

Conclusions

Standardized minimal interventions for the activation of patients’ resources seem to be promising for enhancing the effectiveness of therapeutic Internet chat groups.     

Moral Desirability and Rational Decision

Being a formal and general as well as the most widely accepted approach to practical rationality, rational decision theory should be crucial for justifying rational morals. In particular, acting morally should also (nearly always) be rational in decision theoretic terms. After defending this thesis, in the critical part of the paper two strategies to develop morals following this insight are criticized: game theoretical ethics of cooperation and ethical intuitionism. The central structural objections to ethics of cooperation are that they too directly aim at the rationality of moral action and that they to do not encompass moral values or a moral desirability function. The constructive half of the paper takes up these criticisms by developing a two-part strategy to bring rationality and morals in line. The first part is to define ‘moral desirability’. This is done, using multi-attribute utility theory, by equating several adequate components of an individual’s comprehensive (rational) utility function with the moral desirability function. The second part is to introduce mechanisms, institutions, in particular socially valid moral norms, that provide further motivation for acting in accordance with morals.     

Moderne Antidepressivatherapie

In den letzten drei Jahrzehnten ist es, mit der Entwicklung der so genannten selektiven Serotonin-Wiederaufnahmehemmer (SSRI), zu einer Revolution in der Behandlung der Depression gekommen. Mit dieser Produktgruppe war es erstmals m?glich, depressive Erkrankungen mittels einfacher Strategien (1 × 1 Dosierung) bei hoher Effektivit?t durchzuführen. So haben die Antidepressiva einen Siegeszug um die Welt angetreten und geh?ren heute zu den am h?ufigsten verschriebenen Medikamenten überhaupt. Gerade dadurch wurde eine neue ?ra moderner, antidepressiver Pharmakotherapie eingeleitet. Einer der wesentlichen Effekte dürfte darin liegen, dass in den industrialisierten Staaten seit der Einführung der SSRI die Suizidraten rückl?ufig sind - was eine sensationelle Entwicklung moderner Behandlungsstrategien in der Psychiatrie reflektiert.