Distance stability analysis in multidimensional scaling using the jackknife method

Stability or sensitivity analysis is an important topic in data analysis that has received little attention in the application of multidimensional scaling (MDS), for which the only available approaches are given in terms of a coordinate‐based analytical jackknife methodology. Although in MDS the prime interest is in assessing the stability of the points in the configuration, this methodology may be influenced by imprecisions resulting from the inherently necessary Procrustes method. This paper proposes an analytical distance‐based jackknife procedure to study stability and cross‐validation in MDS in terms of the jackknife distances, which is not influenced by the Procrustes method. For each object, the corresponding jackknife estimated points are considered as naturally clustered points, and stability and cross‐validation are analysed in terms of the MDS distances arising from the jackknife procedure, on the basis of a weighted cluster‐MDS algorithm. A jackknife‐relevant configuration is also proposed for cross‐validation in terms of coordinates, in a cluster‐MDS framework.     

Alternatives to the fixed-set model: A review of appraisal models of emotion

Over several decades, appraisal theory has emerged as a prominent theoretical framework explaining the elicitation and differentiation of emotions, and has stimulated a great deal of theorising and empirical research. Despite the large amount of research in this area, there are many aspects of appraisal theory and research that remain unclear or problematic. In this review, we identify a common assumption of many appraisal theories—the fixed appraisal set—and argue that this assumption, combined with a lack of explicit theorising about the predicted relationship between appraisals and emotions, leads to a lack of clarity in both appraisal models and the empirical testing of those models. We recommend that appraisal theorists move in a direction already taken by a small number of theorists, and adopt the starting assumption of a variable appraisal set. We further suggest that theories of concepts and categorisation may inform theorising about appraisal–emotion relationships.     

Contrasting cue-density effects in causal and prediction judgments

Many theories of contingency learning assume (either explicitly or implicitly) that predicting whether an outcome will occur should be easier than making a causal judgment. Previous research suggests that outcome predictions would depart from normative standards less often than causal judgments, which is consistent with the idea that the latter are based on more numerous and complex processes. However, only indirect evidence exists for this view. The experiment presented here specifically addresses this issue by allowing for a fair comparison of causal judgments and outcome predictions, both collected at the same stage with identical rating scales. Cue density, a parameter known to affect judgments, is manipulated in a contingency learning paradigm. The results show that, if anything, the cue-density bias is stronger in outcome predictions than in causal judgments. These results contradict key assumptions of many influential theories of contingency learning.     

Relative quantity judgments in South American sea lions (<Emphasis Type="Italic">Otaria flavescens</Emphasis>)

There is accumulating evidence that a variety of species possess quantitative abilities although their cognitive substrate is still unclear. This study is the first to investigate whether sea lions (Otaria flavescens), in the absence of training, are able to assess and select the larger of two sets of quantities. In Experiment 1, the two sets of quantities were presented simultaneously as whole sets, that is, the subjects could compare them directly. In Experiment 2, the two sets of quantities were presented item-by-item, and the totality of items was never visually available at the time of choice. For each type of presentation, we analysed the effect of the ratio between quantities, the difference between quantities and the total number of items presented. The results showed that (1) sea lions can make relative quantity judgments successfully and (2) there is a predominant influence of the ratio between quantities on the subjects’ performance. The latter supports the idea that an analogue representational mechanism is responsible for sea lions’ relative quantities judgments. These findings are consistent with previous reports of relative quantities judgments in other species such as monkeys and apes and suggest that sea lions might share a similar mechanism to compare and represent quantities.     

Machismo and Mexican American men: an empirical understanding using a gay sample

Machismo continues to be a defining aspect of Mexican American men that informs a wide array of psychological and behavioral dimensions. Although strides have been made in this area of research, understanding of the role of this construct in the lives of gay men remains incomplete. Our purpose in this study was to gain a deeper understanding of machismo using a sample of Mexican American gay men. This study examined for the first time whether a 2-factor model of machismo previously validated with heterosexual, Mexican American men generalized to a sample of 152 gay men of similar ethnic background. Relations between machismo, sexual risk, and internalized homophobia were also explored. Confirmatory factor analysis supported the 2-factor model with the current sample. Results also indicated machismo as predicting internalized homophobia and as an index of risky sex. Limitations are presented and implications are discussed.     

Lexico-semantic processing in Williams syndrome

People with Williams syndrome, a neurodevelopmental genetic syndrome, typically have good language skills as compared to other cognitive abilities, as far as intellectual disability is concerned. They have a large vocabulary and they frequently use uncommon or rarely-used words. This has led some authors to consider that they have a peculiar semantic system, different from that of people with typical development. In this study, we tested this hypothesis by comparing the performance of a group of young adults with Williams syndrome to a control group using various lexico-semantic tasks, including semantic and phonological fluency. The results indicate that the semantic system of people with Williams syndrome does not seem to differ much from those in the control group because the words they produced were similar to those of the control group with regard to word frequency, length or the typicality of the responses within the categories.     

Compatibility between stimulated eye, target location and response location

Responses to stimuli are faster when the stimulus location spatially corresponds to the required response (standard Simon effect). Recently, a similar effect has been observed with monocular stimuli. Responses were faster when the response location and the stimulated eye corresponded (monocular Simon effect). It has been suggested that distinct mechanisms may underlie these two Simon effects. Here, we attempted to study these two mechanisms simultaneously. For mean reaction time, a finding of perfect additivity was obtained. These behavioral data coupled with surface electrophysiological measures support the view that two different mechanisms contribute independently to the monocular and standard Simon effect.     

Gene knockout of insulin-regulated aminopeptidase: Loss of the specific binding site for angiotensin IV and age-related deficit in spatial memory

The AT₄ ligands, angiotensin IV and LVV-hemorphin 7, elicit robust effects on facilitating memory by binding to a specific site in the brain historically termed the angiotensin AT₄ receptor. The identification of the AT₄ receptor as insulin-regulated aminopeptidase (IRAP) is controversial, with other proteins speculated to be the target(s) of these peptides. In this study we have utilized IRAP knockout mice to investigate IRAP in the brain. We demonstrate that the high-affinity binding site for angiotensin IV is absent in IRAP knockout mice brain sections in parallel with the loss of IRAP immunostaining, providing irrefutable proof that IRAP is the specific high-affinity binding site for AT₄ ligands. However, our characterization of the behavioural phenotype of the IRAP knockout mice revealed a totally unexpected finding. In contrast to the acute effects of IRAP inhibitors in enhancing memory, deletion of the IRAP gene resulted in mice with an accelerated, age-related decline in spatial memory that was only detected in the Y maze paradigm. Moreover, no alterations in behaviour of the IRAP knockout mice were observed that could assist in elucidating the endogenous substrate(s). Our results highlight the importance of analysing the behavioural phenotype of knockout mice across different ages and in distinct memory paradigms.     

Barriers perceived by teachers at work, coping strategies, self-efficacy and burnout

This study examines the relationships among stressors, coping strategies, self-efficacy and burnout in a sample of 724 Spanish primary and secondary teachers. We understood stressors as barriers perceived by teachers that interfere with their work meeting learning objectives and which cause them stress and burnout. An analysis of teacher responses using hierarchical regression revealed that pedagogical barriers had significant positive effects on the burnout dimensions. Furthermore, the results show not only the moderator role played by coping strategies in the pedagogical barriers-burnout dimensions relationship, but also the association between self-efficacy and the coping strategies used by teachers. Practical implications are discussed.     

On the mental representations originating during the interaction between language and vision

The interaction between vision and language processing is clearly of interest to both cognitive psychologists and psycholinguists. Recent research has begun to create understanding of the interaction between vision and language in terms of the representational issues involved. In this paper, we first review some of the theoretical and methodological issues in the current vision–language interaction debate. Later, we develop a model that attempts to account for effects of affordances and visual context on language-scene interaction as well as the role of sensorimotor simulation. The paper addresses theoretical issues related to the mental representations that arise when visual and linguistic systems interact.