Environmental cue saliency influences the vividness of a remote spatial memory in rats

The Morris water maze is frequently used to evaluate the acquisition and retrieval of spatial memories. Few experiments, however, have investigated the effects of environmental cue saliency on the strength or persistence of such memories after a short vs. long post-acquisition interval. Using a Morris water maze, we therefore tested in rats the effect of the saliency of distal cues on the vividness of a recent (5 days) vs. remote (25 days) memory. Rats trained in a cue-enriched vs. a cue-impoverished context showed a better overall level of performance during acquisition. Furthermore, the probe trials revealed that the rats trained and tested in the cue-impoverished context (1) spent less time in the target quadrant at the 25-day delay, and (2) swam shorter distances in the target area, with fewer crossings at both 5- and 25-day delays, as compared to their counterparts trained and tested in the cue-enriched context. Thus, the memory trace formed in the cue-enriched context shows better resistance to time, suggesting an implication of cue saliency in the vividness of a spatial memory.     

Directed forgetting and aging: the role of retrieval processes, processing speed, and proactive interference

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

STOP-IT: Windows executable software for the stop-signal paradigm

The stop-signal paradigm is a useful tool for the investigation of response inhibition. In this paradigm, subjects are instructed to respond as fast as possible to a stimulus unless a stop signal is presented after a variable delay. However, programming the stop-signal task is typically considered to be difficult. To overcome this issue, we present software called STOP-IT, for running the stop-signal task, as well as an additional analyzing program called ANALYZE-IT. The main advantage of both programs is that they are a precompiled executable, and for basic use there is no need for additional programming. STOP-IT and ANALYZE-IT are completely based on free software, are distributed under the GNU General Public License, and are available at the personal Web sites of the first two authors or at expsy.ugent.be/tscope/stop.html.     

A longitudinal assessment of executive function skills and their association with math performance.

The present study was designed to examine both concurrent and predictive associations between scores on a measure of executive function (EF) skills, the Contingency Naming Test (CNT), during the early school-age years. A secondary aim of the study was to examine the association between EF skills and mathematics performance. We administered tests of mathematics ability, and the CNT, to 178 children at ages 6 to 7, 8 to 9, and 10 to 11 years. From the CNT we obtained measures of response fluency/efficiency, working memory, and inhibition. The results demonstrate main effects of age on all CNT measures of EF, as anticipated, and inconsistent main effects of gender or mathematics learning disability status. Rates of improvement in EF varied as a function of the working memory demands present during a given task. There were differences in concurrent and predictive correlations for different CNT performance measures. EF scores obtained during the first assessment were as strongly associated with each other as they were with EF scores obtained four years later, suggesting a moderately stable source of individual differences on cognitive performance. EF scores at age 6 to 7 years were associated with concurrent and later mathematics scores, and most of these correlations were stronger than the significant associations found between response fluency on a baseline task (with no working memory demand) and mathematics performance. These findings have implications for the stability of EF skills during the school-age years, and the role of EF in early and later elementary school mathematics performance.     

Nonlinear principal components analysis: introduction and application

The authors provide a didactic treatment of nonlinear (categorical) principal components analysis (PCA). This method is the nonlinear equivalent of standard PCA and reduces the observed variables to a number of uncorrelated principal components. The most important advantages of nonlinear over linear PCA are that it incorporates nominal and ordinal variables and that it can handle and discover nonlinear relationships between variables. Also, nonlinear PCA can deal with variables at their appropriate measurement level; for example, it can treat Likert-type scales ordinally instead of numerically. Every observed value of a variable can be referred to as a category. While performing PCA, nonlinear PCA converts every category to a numeric value, in accordance with the variable's analysis level, using optimal quantification. The authors discuss how optimal quantification is carried out, what analysis levels are, which decisions have to be made when applying nonlinear PCA, and how the results can be interpreted. The strengths and limitations of the method are discussed. An example applying nonlinear PCA to empirical data using the program CATPCA (J. J. Meulman, W. J. Heiser, & SPSS, 2004) is provided.     

Neuroticism and responses to social comparison among cancer patients

The present study examined how the effects of three audiotapes containing different types of social comparison information on the mood of cancer patients depended on the level of neuroticism. On the procedural tape, a man and woman discussed the process of radiation therapy, on the emotion tape, they focussed on emotional reactions to their illness and treatment, while on the coping tape they focussed on the way they had been coping. A validation study among 115 students showed that the tapes were perceived as they were intended. The main study was conducted among 226 patients who were about to undergo radiation therapy. Compared to patients in the control group, as patients were higher in neuroticism, they reported less negative mood after listening to the procedural and the coping tape. Furthermore, as patients were higher in neuroticism, they reported less negative mood after listening to the coping tape than to the emotion tape. Copyright © 2009 John Wiley & Sons, Ltd.     

Interpersonal Problems Among Perpetrators and Targets of Workplace Bullying

This representative study among 2,539 Norwegian employees examines interpersonal problems among targets and perpetrators of workplace bullying. Both targets and perpetrators portrayed elevated levels of interpersonal problems. Yet, the results question the role of a general target personality in explaining exposure to workplace bullying. Although interpersonal problems were reported among 50% of the targets, interpersonal problems were also prevalent in a large proportion of the non-exposed employees. Accordingly, level of interpersonal problems does not easily differentiate targets from non-targets and calls for a broader frame of reference in order to understand the bullying process.     

Children's perception and understanding of (dis)similarities among dynamic bodily/facial expressions of happiness, pleasure, anger, and irritation

The current study examined the abilities of children (6 and 8 years of age) and adults to freely categorize and label dynamic bodily/facial expressions designed to portray happiness, pleasure, anger, irritation, and neutrality and controlled for their level of valence, arousal, intensity, and authenticity. Multidimensional scaling and cluster analyses showed that children (n = 52) and adults (n = 33) structured expressions in systematic and broadly similar ways. Between 6 and 8 years of age, there was a quantitative, but not a qualitative, improvement in labeling. When exposed to rich and dynamic emotional cues, children as young as 6 years can successfully perceive differences between close expressions (e.g., happiness, pleasure), and can categorize them with clear boundaries between them, with the exception of irritation, which had fuzzier borders. Children’s classifications were not reliant on lexical semantic abilities and were consistent with a model of emotion categories based on their degree of valence and arousal.     

Family criticism and self-starvation: a study of expressed emotion

The measure Expressed Emotion (EE) has been established as an exceptionally useful indicator of relapse in people with schizophrenia and depression. EE is now also being applied more broadly for the investigation of other disorders. EE is usually rated by conducting the Camberwell Family Interview, i.e. in the course of separate individual interviews with the relatives of the symptomatic individuals. This paper reports the rating of EE in adolescents with eating disorders within a semi-structured family schedule - the Standardized Clinical Family Interview. Consecutive referrals for eating disorders were assessed prior to family therapy and again at regular intervals during therapy. EE ratings for this sample, the prognostic value of EE, and the changes in EE that took place during the course of therapy are presented and their clinical implications discussed. The findings suggest that even low levels of Critical Comments from the parents to the anorexic adolescent are associated with continuing symptoms.