Task switching: effects of practice on switch and mixing costs

In the task-switching paradigm, mixing costs indicate the performance costs to mix two different tasks, while switch costs indicate the performance costs to switch between two sequentially presented tasks. Applying tasks with bivalent stimuli and responses, many studies demonstrated substantial mixing and switch costs and a reduction of these costs as a result of practice. The present study investigates whether extensive practice of a task-switching situation including tasks with univalent stimuli eliminates these costs. Participants practiced switching between a visual and an auditory task. These tasks were chosen because they had shown eliminated performance costs in a comparable dual-task practice study (Schumacher et al. Psychol Sci 12:101–108, 2001). Participants either performed the tasks with univalent responses (i.e., visual-manual and auditory-verbal stimulus–response mappings) or bivalent responses (i.e., visual-manual and auditory-manual stimulus–response mappings). Both valence conditions revealed substantial mixing and switch costs at the beginning of practice, yet, mixing costs were largely eliminated after eight practice sessions while switch costs were still existent.     

Competitiveness across the life span: the feisty fifties

Existing theories on life span changes in confidence or motivation suggest that individuals' preferences to enter competitive situations should gradually decline with age. We examined competitive preferences in a field experiment using real financial stakes in 25- to 75-year-olds (N = 543). The critical dependent variable was whether participants chose to perform a simple mental arithmetic task either under a piece-rate payment schedule (i.e., $.25 per solved item) or a competitive payment schedule ($.50 per solved item if the overall score is better than that of a randomly selected opponent, $0 otherwise). Results revealed that competitive preferences increased across the life span until they peaked around age 50, and dropped thereafter. We also found that throughout, men had a substantially larger preference for competing than women-extending previous findings on college-aged participants. The age/gender differences in preferences were neither accounted for by actual differences in performance nor individuals' subjective confidence. This first systematic attempt to characterize age differences in competitive behavior suggests that a simple decline conception of competitiveness needs to be reconsidered.     

Challenge me! Communicating in multicultural classrooms

The current study investigated the value of Socratic classroom communication (e.g., critical debate and challenging each other on content matters) among students from various cultures (clustered into Western Europeans, Eastern Europeans and Non-Europeans) and from members of faculty at an international university in Germany. Students from Western cultures where Socratic communication had been valued in the school systems reported a greater ease of engaging in the respective communication style than did Eastern European and Non-European students. Furthermore, we assessed how strongly the faculty valued the respective kinds of behavior. The results show that overall students underestimated the extent to which Socratic communication behavior was esteemed by members of faculty. In addition, faculty members perceived themselves to be more explicit about their pedagogical principles than they were perceived by students. Finally, the easier it was for students to show Socratic classroom communication, the more academically satisfied they were and the better their grades. The results are discussed with regard to practical implications and the internationalization of universities.     

Emotional response to musical repetition

Two experiments examined the effects of repetition on listeners' emotional response to music. Listeners heard recordings of orchestral music that contained a large section repeated twice. The music had a symmetric phrase structure (same-length phrases) in Experiment 1 and an asymmetric phrase structure (different-length phrases) in Experiment 2, hypothesized to alter the predictability of sensitivity to musical repetition. Continuous measures of arousal and valence were compared across music that contained identical repetition, variation (related), or contrasting (unrelated) structure. Listeners' emotional arousal ratings differed most for contrasting music, moderately for variations, and least for repeating musical segments. A computational model for the detection of repeated musical segments was applied to the listeners' emotional responses. The model detected the locations of phrase boundaries from the emotional responses better than from performed tempo or physical intensity in both experiments. These findings indicate the importance of repetition in listeners' emotional response to music and in the perceptual segmentation of musical structure.     

Estimating discrimination performance in two-alternative forced choice tasks: Routines for MATLAB and R

Ulrich and Vorberg (Attention, Perception, & Psychophysics 71: 1219–1227, 2009) introduced a novel approach for estimating discrimination performance in two-alternative forced choice (2AFC) tasks. This approach avoids pitfalls that are inherent when the order of the standard and the comparison is neglected in estimating the difference limen (DL), as in traditional approaches. The present article provides MATLAB and R routines that implement this novel procedure for estimating DLs. These routines also allow to account for processing failures such as lapses or finger errors and can be applied to experimental designs in which the standard and comparison differ only along the task-relevant dimension, as well as to designs in which the stimuli differ in more than one dimension. In addition, Monte Carlo simulations were conducted to check the quality of our routines.     

Producing and recognizing words with two pronunciation variants: evidence from novel schwa words

This study examined the lexical representations and psycholinguistic mechanisms underlying the production and recognition of novel words with two pronunciation variants in French. Participants first learned novel schwa words (e.g., /??nyk/), which varied in their alternating status (i.e., whether these words were learned with one or two variants) and, for alternating words, in the frequency of their variants. They were then tested in picture-naming (free or induced) and recognition memory tasks (i.e., deciding whether spoken items were learned during the experiment or not). Results for free naming show an influence of variant frequency on responses, more frequent variants being produced more often. Moreover, our data show an effect of the alternating status of the novel words on naming latencies, with longer latencies for alternating than for nonalternating novel words. These induced naming results suggest that both variants are stored as lexical entries and compete during the lexeme selection process. Results for recognition show an effect of variant frequency on reaction times and no effect of variant type (i.e., schwa versus reduced variant). Taken together, our findings suggest that participants both comprehend and produce novel French schwa words using two lexical representations, one for each variant.     

Pricing risk and ambiguity: the effect of perspective taking

In the valuation of uncertain prospects, a difference is often observed between selling and buying perspectives. This paper distinguishes between risk (known probabilities) and ambiguity (unknown probabilities) in decisions under uncertainty and shows that the valuation disparity increases under ambiguity compared to risk. It is found that both the comparative versus noncomparative evaluation of risky and ambiguous prospects and the uniqueness of the valuation perspective (either seller or buyer) moderate this increase in the disparity under ambiguity. The finding is consistent with recent theoretical accounts of pricing under uncertainty. We discuss implications for market behaviour and for the ambiguity paradigm as a research tool.     

Zur Validit?t des Prognoseinstruments ?Rückfallrisiko bei Sexualstraft?tern“

The Risk for Recidivism in Sexual Offenders (RRS) procedure is an actuarial risk assessment tool designed to predict recidivism in sexual offenders released from prison. So far it is the only tool developed with a German sample and uses a combination of 11 static and dynamic risk markers. The goal of the current study was to test the predictive validity of the 3 RRS prognostic scores in a sample of 104 sexual offenders whose prison files and recidivism data were analysed after a mean period of 8 years after release from a German prison. The H-score of the RRS developed to assess the probability of reimprisonment showed moderate to good predictive power in relation to any new convictions, new convictions leading to a prison term and new convictions for an aggressive or sexual criminal offence. As expected it was not able to predict sexual recidivism which had a base rate of 8.7% in this sample. The S-score and the K-score of the RRS developed to predict this criterion, performed hardly better in this task. These scores showed moderate to good predictive validity only in the small subsample of extrafamilial sexual offenders.     

Trial-by-trial updating of an internal reference in discrimination tasks: Evidence from effects of stimulus order and trial sequence

In psychophysics, participants are often asked to discriminate between a constant standard and a variable comparison. Previous studies have shown that discrimination performance is better when the comparison follows, rather than precedes, the standard. Prominent difference models of psychophysics and decision making cannot easily explain this order effect. However, a simple extension of this model class involving dynamical updating of an internal reference accounts for this order effect. In addition, this Internal Reference Model (IRM) predicts sequential response effects. We examined the predictions of IRM in two duration discrimination experiments. The obtained results are in agreement with the predictions of IRM, suggesting that participants update their internal reference on every trial. Additional simulations show that IRM also accounts for the negative sequential effects observed in single-stimulus paradigms.     

Implizites Beziehungswissen

Implicit relational knowing is for the most part procedural implicit knowing. Implicit relational knowing operates outside verbal experience and is mostly expressed in actions and constitutes the ‘how’ of being with others. Interpersonal relationships develop step by step and even subtle behavioral means can be a step. A subsequent step documents how the person interprets the preceding behavior of the other person. According to the Boston Change Process Study Group (BCPSG), implicit relational knowing can change with increasing integration and coherence in the therapeutic process. This enables the patient to bring into the therapeutic relationship even difficult and affectively charged experiences which thus become “relationable” for the patient.