Towards tolerance: Representations of superordinate categories and perceived ingroup prototypicality

According to Mummendey and Wenzel (1999), group members tend to perceive their ingroup, relative to an outgroup, as more prototypical of the superordinate category encompassing both groups. Hence, they tend to regard the outgroup as deviating from the norms of the superordinate category. Factors that inhibit perception of relative ingroup prototypicality should thus promote intergroup tolerance. In two experiments, the representation of the superordinate category was manipulated. Both an undefinable prototype (Experiment 1; N=63) and a complex representation (Experiment 2; N=88) led to a decrease in relative ingroup prototypicality. Dual identification with the ingroup and the superordinate category increased relative ingroup prototypicality, which was negatively correlated with positive attitudes towards the outgroup. The findings supported Mummendey and Wenzel’s assumptions about the conditions that lead to intergroup tolerance.     

Does resting electroencephalograph asymmetry reflect a trait? an application of latent state-trait theory

Recent research on brain asymmetry and emotion treated measures of resting electroencephalograph (EEG) asymmetry as genuine trait variables, but inconsistency in reported findings and modest retest correlations of baseline asymmetry are not consistent with this practice. The present study examined the alternative hypothesis that resting EEG asymmetry represents a superimposition of a traitlike activation asymmetry with substantial state-dependent fluctuations. Resting EEG was collected from 59 participants on 4 occasions of measurement, and data were analyzed in terms of latent state-trait theory. For most scalp regions, about 60% of the variance of the asymmetry measure was due to individual differences on a temporally stable latent trait, and 40% of the variance was due to occasion-specific fluctuations, but measurement errors were negligible. Further analyses indicated that these fluctuations might be efficiently reduced by aggregation across several occasions.     

Correlation between tests of attention and performance on grooved and Purdue pegboards in normal subjects

This study investigated the relation between tests of manual dexterity and attentional functions with 49 normal, right-handed medical students (26 women, 23 men, ages 19-30 years) who were assessed with a Purdue Pegboard Test, Grooved Pegboard Test, and a Test for Attentional Performance, comprising measures of tonic and phasic alertness and divided attention. Weak to moderately high partial correlations controlling for finger size were obtained between pegboard test performance of the left hand and phasic alertness (r = .31-.50). Purdue Pegboard Assembly subtest scores were weakly correlated with divided attention (r = -.39). These findings suggest that attention is an important determinant of performance for manual dexterity tests of the nondominant hand.     

Psycholinguistic evidence for the underspecification of morphosyntactic features

This paper investigates the paradigmatic relations between inflected word forms (or their affixes) and the feature specifications of these elements. In two sentence-matching experiments German speakers had to decide whether sentence pairs involving inflected adjectives or determiners were identical or not. In both experiments, there was a delay when an inflected form contained positive feature specifications for grammatical features that did not match the feature specifications of the grammatical context in which it appeared. No delay, however, occurred when an incorrectly inflected form had mismatching negative specifications, whereas its positively specified features matched the respective positive features of the context. This result provides evidence for a different status of positively and negatively specified morphosyntactic features. It supports the idea of radical underspecification according to which only positive feature specifications are part of the representations of morphologically complex forms or affixes, whereas negative feature specifications are assigned on the basis of paradigmatic contrasts.     

Convex hull and tour crossings in the Euclidean traveling salesperson problem: Implications for human performance studies

Recently there has been growing interest among psychologists in human performance on the Euclidean traveling salesperson problem (E-TSP). A debate has been initiated on what strategy people use in solving visually presented E-TSP instances. The most prominent hypothesis is the convex-hull hypothesis, originally proposed by MacGregor and Ormerod (1996). We argue that, in the literature so far, there is no evidence for this hypothesis. Alternatively we propose and motivate the hypothesis that people aim at avoiding crossings.     

Altered behavioral and neural responsiveness to counterfactual gains in the elderly

Counterfactual information processing refers to the consideration of events that did not occur in comparison to those actually experienced, in order to determine optimal actions, and can be formulated as computational learning signals, referred to as fictive prediction errors. Decision making and the neural circuitry for counterfactual processing are altered in healthy elderly adults. This experiment investigated age differences in neural systems for decision making with knowledge of counterfactual outcomes. Two groups of healthy adult participants, young (N = 30; ages 19–30 years) and elderly (N = 19; ages 65–80 years), were scanned with fMRI during 240 trials of a strategic sequential investment task in which a particular strategy of differentially weighting counterfactual gains and losses during valuation is associated with more optimal performance. Elderly participants earned significantly less than young adults, differently weighted counterfactual consequences and exploited task knowledge, and exhibited altered activity in a fronto-striatal circuit while making choices, compared to young adults. The degree to which task knowledge was exploited was positively correlated with modulation of neural activity by expected value in the vmPFC for young adults, but not in the elderly. These findings demonstrate that elderly participants’ poor task performance may be related to different counterfactual processing.