Memory activation and the availability of explanations in sequential diagnostic reasoning

In the field of diagnostic reasoning, it has been argued that memory activation can provide the reasoner with a subset of possible explanations from memory that are highly adaptive for the task at hand. However, few studies have experimentally tested this assumption. Even less empirical and theoretical work has investigated how newly incoming observations affect the availability of explanations in memory over time. In this article we present the results of 2 experiments in which we address these questions. While participants diagnosed sequentially presented medical symptoms, the availability of potential explanations in memory was measured with an implicit probe reaction time task. The results of the experiments were used to test 4 quantitative cognitive models. The models share the general assumption that observations can activate and inhibit explanations in memory. They vary with respect to how newly incoming observations affect the availability of explanations over time. The data of both experiments were predicted best by a model in which all observations in working memory have the same potential to activate explanations from long-term memory and in which these observations do not decay. The results illustrate the power of memory activation processes and show where additional deliberate reasoning strategies might come into play.     

Cultural and Institutional Determinants of Social Dominance Orientation: A Cross‐Cultural Meta‐Analysis of 27 Societies

We investigate macrocontextual antecedents of national levels of Social Dominance Orientation (SDO). The majority of previous research, in contrast, has tended to focus on individual‐level correlates of SDO. We extend research on Social Dominance Theory by modelling national‐level differences in institutional discrimination, macroeconomic development, and value ideologies as broad situational factors affecting SDO mean levels in previous studies. Our hypotheses were tested in a three‐level meta‐analysis of aggregate data from 50,971 individuals in 95 samples from 27 different societies. Strong effects for hierarchy‐attenuating legitimizing ideologies and gender empowerment were found. Aggregate discrimination against arbitrary‐set groups was less consistently linked to SDO, suggesting that these hierarchies are context‐specific. Using mixed‐effects three‐level modelling, the patterns can be generalized to new contexts and suggest a particular institutional and social climate that fosters high SDO.     

A glass full of optimism: Enrichment effects on cognitive bias in a rat model of depression

Investigations of cognitive biases in animals are conceptually and translationally valuable because they contribute to animal welfare research and help to extend and refine our understanding of human emotional disorders, where biased information processing is a critical causal and maintenance factor. We employed the "learned helplessness" genetic rat model of depression in studying cognitive bias and its modification by environmental manipulations. Using a spatial judgment task, responses to ambiguous spatial cues were assessed before and after environmental enrichment to test whether this manipulation would cause an optimistic shift in emotional state. Twenty-four congenitally helpless and nonhelpless male rats were trained to discriminate two different locations, "rewarded" versus "aversive." After successful acquisition of this spatial discrimination, cognitive bias was probed by measuring responses to three ambiguous locations. Latencies to "reach" and to actively "choose" a goal pot were recorded alongside exploratory behaviors. An overall strain difference was observed, with helpless rats displaying longer "reach" latencies than nonhelpless rats. This implies a "pessimistic" response bias in helpless rats, underscoring their depressive-like phenotype. No strain differences were observed regarding other behavioral measures. Half of the animals were then transferred to enriched cages and retested. Environmental enrichment resulted in reduced "choose" latencies in both rat strains, associating enrichment with more optimistic interpretations of ambiguous cues. Our results emphasize the suitability of cognitive bias measurement for animal emotion assessment. They extend the methodological repertoire for characterizing complex phenotypes and bear implications for animal welfare research and for the use of animal models in preclinical research.     

Gibbons (Hylobates pileatus, H. moloch, H. lar, Symphalangus syndactylus) follow human gaze, but do not take the visual perspective of others

We investigated four gibbon species of two different genera (Hylobates pileatus, H. moloch, H. lar, Symphalangus syndactylus) in terms of their looking behavior in response to a human who either looked up or looked at the gibbon. Comparing those two conditions, gibbons as a group looked up more when the human was looking up, but they also performed more looks in other directions and thus generally looked more in this condition. Unlike great apes, gibbons did not respond differently between conditions when only the first look on every trial was considered. Furthermore, they did not perform double looks up to check where the human was looking and also did not habituate to the human’s looks up. This suggests that gibbons co-orient with human gaze, but unlike great apes, they do not take the visual perspective of others.     

Comparing graphic and symbolic classification in interactive multiobjective optimization

In interactive multiobjective optimization systems, the classification of objective functions is a convenient way to direct the solution process in order to search for new, more satisfactory, solutions in the set of Pareto optimal solutions. Classification means that the decision maker assigns the objective functions into classes depending on what kind of changes in their values (in relation to the current values) are desirable. Here we study the role of user interfaces in implementing classification in multiobjective optimization software and how classification should be realized. In this way, we want to pay attention to the usability of multiobjective optimization software. Typically, this topic has not been of interest in the multiobjective optimization literature. However, usability aspect is important because in interactive classification‐based multiobjective optimization methods, the classification is the core of the solution process. We can say that the more convenient the classification is, the more efficient the system or the method is and the better it supports the work of the decision maker. We report experiments with two classification options, graphic and symbolic ones, which are used in connection with an interactive multiobjective optimization system WWW‐NIMBUS. The ideas and conclusions given are applicable for other interactive classification‐based method, as well. Copyright © 2005 John Wiley & Sons, Ltd.     

Children report suggested events even when interviewed in a non-suggestive manner: what are its implications for credibility assessment?

An important question in the legal context is how suggested statements about fictitious events develop over a course of various interviews. Sixty-seven first-graders were interviewed four times about one real and one fictitious event, applying various suggestive techniques. A fifth, non-suggestive, interview was conducted by blind experts. Over the course of the interviews there was a considerable increase in assents to the fictitious events. Moreover, few significant differences in criteria-based content analysis-criteria were revealed between true and fictitious statements in the fifth interview. Accordingly, experts had difficulties in discriminating between true and suggested accounts. Furthermore, several children were convinced of the truth of their reports, even after having been partially debriefed in a sixth interview. Implications for statement validity assessment are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

Measuring illness perceptions in the family context: psychometric properties of the IPQ-R adapted for adolescent–caregiver dyads

Objectives: Given the lack of validated measures assessing illness perceptions in families, the aim of our study was the development and psychometric testing of an adapted version of the Illness Perceptions Questionnaire-Revised (IPQ-R) allowing for Common Sense Model-based dyadic assessment of adolescents’ and caregivers’ perceptions of a chronic illness in adolescence.

Methods: Using a cross-sectional survey design, factor structure, reliability and validity of the adapted measure You-IPQ-R were tested in a sample of adolescents with asthma (N?=?155) and their primary caregivers (N?=?132). Analysis included a dyadic methodology (dyadic confirmatory factor analyses) and examination of the suitability of the measure for different age groups.

Results: Both the adolescent and the caregiver versions of the You-IPQ-R revealed good overall validity and reliability. For all Common Sense Model dimensions except for timeline cyclical in the caregiver version, unidimensional scales aligning with the original IPQ-R structure could be confirmed. Age-specific analyses revealed good to excellent measurement properties in adolescents aged 14 years or older, but considerably poorer indices in younger adolescents.

Conclusion: The dyadically validated You-IPQ-R will enable researchers and clinicians to compare illness perceptions in adolescent–caregiver dyads and to assess the effects of family illness perceptions’ congruence upon medical, psychosocial and behavioural outcomes.