Study of behavioural and neural bases of visuo‐spatial working memory with an fMRI paradigm based on an n‐back task

The goal of this study was to propose a new functional magnetic resonance imaging (fMRI) paradigm using a language‐free adaptation of a 2‐back working memory task to avoid cultural and educational bias. We additionally provide an index of the validity of the proposed paradigm and test whether the experimental task discriminates the behavioural performances of healthy participants from those of individuals with working memory deficits. Ten healthy participants and nine patients presenting working memory (WM) deficits due to acquired brain injury (ABI) performed the developed task. To inspect whether the paradigm activates brain areas typically involved in visual working memory (VWM), brain activation of the healthy participants was assessed with fMRIs. To examine the task's capacity to discriminate behavioural data, performances of the healthy participants in the task were compared with those of ABI patients. Data were analysed with GLM‐based random effects procedures and t‐tests. We found an increase of the BOLD signal in the specialized areas of VWM. Concerning behavioural performances, healthy participants showed the predicted pattern of more hits, less omissions and a tendency for fewer false alarms, more self‐corrected responses, and faster reaction times, when compared with subjects presenting WM impairments. The results suggest that this task activates brain areas involved in VWM and discriminates behavioural performances of clinical and non‐clinical groups. It can thus be used as a research methodology for behavioural and neuroimaging studies of VWM in block‐design paradigms.     

Word recognition in Alzheimer's disease: Effects of semantic degeneration

Impairments of word recognition in Alzheimer's disease (AD) have been less widely investigated than impairments affecting word retrieval and production. In particular, we know little about what makes individual words easier or harder for patients with AD to recognize. We used a lexical selection task in which participants were shown sets of four items, each set consisting of one word and three non‐words. The task was simply to point to the word on each trial. Forty patients with mild‐to‐moderate AD were significantly impaired on this task relative to matched controls who made very few errors. The number of patients with AD able to recognize each word correctly was predicted by the frequency, age of acquisition, and imageability of the words, but not by their length or number of orthographic neighbours. Patient Mini‐Mental State Examination and phonological fluency scores also predicted the number of words recognized. We propose that progressive degradation of central semantic representations in AD differentially affects the ability to recognize low‐imageability, low‐frequency, late‐acquired words, with the same factors affecting word recognition as affecting word retrieval.     

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.     

The willingness of medical students to use Facebook as a training channel for professional habits: the case of influenza vaccination

The low acceptance of influenza vaccination by both medical students and healthcare workers (HCWs) signals the need for innovative strategies. We administered an anonymous questionnaire to 410 University of Barcelona medical students who were asked about using the Internet to find information on influenza vaccination of HCWs and about their willingness to use technical and informal Facebook pages as an information channel on this topic. Of the 410 participants, 74.1 percent were female and 58.3 percent were in the first preclinical 3-year university cycle. A total of 7.6 percent participants reported using the Internet for queries on influenza vaccination, 89.8 percent reported that they were Facebook users, and 275 (67.1 percent) would accept an invitation from the technical or informal Facebook pages. The technical Web site would be actively followed by 77, or by 30.0 percent of those who would accept the invitation and the informal site by 116 (43.6 percent of those who would accept). The marked willingness to use Facebook to obtain information on the influenza vaccination of HCWs potentially opens a new window in health education: social networks could be used to help create professional habits. Students would be more likely to engage with this type of Facebook page if the contents were informal rather than highly technical.     

Borderline personality traits in nonclinical young adults

The main purpose of this study was to explore the dimensionality of the borderline personality disorder in nonclinical young adults by means of the Borderline Personality Questionnaire (BPQ; Poreh et al., 2006). We also studied the phenotypic expression of the borderline personality traits as a function of participants' gender and age, and the relationship between BPQ subscales and measures of depressive symptoms, anxiety, stress, hallucinatory predisposition, and paranoid ideation. The sample comprised 809 young adults, 562 (69.5%) were women, with a mean age of 20.2 years (SD = 2.9). The results indicate that the BPQ self-report has adequate psychometric properties. The levels of internal consistency for the BPQ subscales ranged between .78 and .93. Analysis of the internal structure of the BPQ subscales yielded a one-dimensional solution. In contrast, second-order principal components analysis at the item level yielded a five-dimensional solution. Likewise, statistically significant differences in the mean scores of the borderline personality traits as a function of participants' gender and age were found. The BPQ subscales correlated significantly with measures of depression, anxiety, stress, paranoid ideation, and hallucinatory predisposition. These results help to improve our understanding of the dimensional structure of the borderline personality in the general population. Future research should continue to identify participants who are at risk for the development of borderline personality disorder and facilitating the development of early detection and prevention programs.     

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.     

The use of the effect size in JCR Spanish journals of psychology: from theory to fact

In 1999, Wilkinson and the Task Force on Statistical Inference published "Statistical Methods and Psychology: Guidelines and Explanation." The authors made several recommendations about how to improve the quality of Psychology research papers. One of these was to report some effect-size index in the results of the research. In 2001, the fifth edition of the Publication Manual of the American Psychological Association included this recommendation. In Spain, in 2003, scientific journals like Psicothema or the International Journal of Clinical and Health Psychology (IJCHP) published editorials and papers expressing the need to calculate the effect size in the research papers. The aim of this study is to determine whether the papers published from 2003 to 2008 in the four Spanish journals indexed in the Journal Citation Reports have reported some effect-size index of their results. The findings indicate that, in general, the followup of the norm has been scanty, though the evolution over the analyzed period is different depending on the journal.     

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.     

A model for the time-order error in contrast discrimination

Trials in a temporal two-interval forced-choice discrimination experiment consist of two sequential intervals presenting stimuli that differ from one another as to magnitude along some continuum. The observer must report in which interval the stimulus had a larger magnitude. The standard difference model from signal detection theory analyses poses that order of presentation should not affect the results of the comparison, something known as the balance condition (J.-C. Falmagne, 1985, in Elements of Psychophysical Theory). But empirical data prove otherwise and consistently reveal what Fechner (1860/1966, in Elements of Psychophysics) called time-order errors, whereby the magnitude of the stimulus presented in one of the intervals is systematically underestimated relative to the other. Here we discuss sensory factors (temporary desensitization) and procedural glitches (short interstimulus or intertrial intervals and response bias) that might explain the time-order error, and we derive a formal model indicating how these factors make observed performance vary with presentation order despite a single underlying mechanism. Experimental results are also presented illustrating the conventional failure of the balance condition and testing the hypothesis that time-order errors result from contamination by the factors included in the model.