Reconsolidation of declarative memory in humans

The reconsolidation hypothesis states that a consolidated memory could again become unstable and susceptible to facilitation or impairment for a discrete period of time after a reminder presentation. The phenomenon has been demonstrated in very diverse species and types of memory, including the human procedural memory of a motor skill task but not the human declarative one. Here we provide evidence for both consolidation and reconsolidation in a paired-associate learning (i.e., learning an association between a cue syllable and the respective response syllable). Subjects were given two training sessions with a 24-h interval on distinct verbal material, and afterward, they received at testing two successive retrievals corresponding to the first and second learning, respectively. Two main results are noted. First, the first acquired memory was impaired when a reminder was presented 5 min before the second training (reconsolidation), and also when the second training was given 5 min instead of 24 h after the first one (consolidation). Second, the first retrieval proved to influence negatively on the later one (the retrieval-induced forgetting [RIF] effect), and we used the absence of this RIF effect as a very indicator of the target memory impairment. We consider the demonstration of reconsolidation in human declarative memory as backing the universality of this phenomenon and having potential clinical relevance. On the other hand, we discuss the possibility of using the human declarative memory as a model to address several key topics of the reconsolidation hypothesis.     

Emotion recognition and expression in young obese participants: preliminary study

This study of the presence of alexithymic characteristics in obese adolescents and preadolescents tested the hypothesis of whether they showed impaired recognition and expression of emotion. The sample included 30 obese young participants and a control group of 30 participants of normal weight for their ages. Stimuli, 42 faces representing seven emotional expressions, were shown to participants who identified the emotion expressed in the face. The Level of Emotional Awareness Scale was adapted for children to evaluate their ability to describe their emotions. Young obese participants had significantly lower scores than control participants, but no differences were found in recognition of emotion. The lack of words to describe emotions might suggest a greater prevalence of alexithymic characteristics in the obese participants, but the hypothesis of a general deficit in the processing of emotional experiences was not supported.     

A neurobiological theory of automaticity in perceptual categorization

A biologically detailed computational model is described of how categorization judgments become automatic in tasks that depend on procedural learning. The model assumes 2 neural pathways from sensory association cortex to the premotor area that mediates response selection. A longer and slower path projects to the premotor area via the striatum, globus pallidus, and thalamus. A faster, purely cortical path projects directly to the premotor area. The model assumes that the subcortical path has greater neural plasticity because of a dopamine-mediated learning signal from the substantia nigra. In contrast, the cortical-cortical path learns more slowly via (dopamine independent) Hebbian learning. Because of its greater plasticity, early performance is dominated by the subcortical path, but the development of automaticity is characterized by a transfer of control to the faster cortical-cortical projection. The model, called SPEED (Subcortical Pathways Enable Expertise Development), includes differential equations that describe activation in the relevant brain areas and difference equations that describe the 2- and 3-factor learning. A variety of simulations are described, showing that the model accounts for some classic single-cell recording and behavioral results.     

Sensitivity to tonality across the pitch range

Striking changes in sensitivity to tonality across the pitch range are reported. Participants were presented a key-defining context (do-mi-do-sol) followed by one of the 12 chromatic tones of the octave, and rated the goodness of fit of the probe tone to the context. The set of ratings, called the probe-tone profile, was compared to an established standardised profile for the Western tonal hierarchy. The presentation of context and probe tones at low and high pitch registers resulted in significantly reduced sensitivity to tonality. Sensitivity was especially poor for presentations in the lowest octaves where inharmonicity levels were substantially above the threshold for detection. We propose that sensitivity to tonality may be influenced by pitch salience (or a co-varying factor such as exposure to pitch distributional information) as well as suprathreshold inharmonicity.     

Day-to-day body-image states: prospective predictors of intra-individual level and variability

Most body-image research has focused on the trait level of body-image evaluation, often neglecting the momentary fluctuations many people experience in everyday life. The present prospective study investigated whether theory-relevant body-image measures, perfectionistic self-presentation, and eating attitudes would predict average day-to-day body-image levels and their intra-individual variability. A convenience sample consisted of 121 women from two universities. In Phase 1 of the study, participants completed an online battery of selected body-image and personality questionnaires. In Phase 2, participants went online to complete the dependent measure, the Body Image States Scale, once per evening over 10 days. As hypothesized, more favorable body-image state levels were associated with less investment in appearance for self-worth, less body-image disturbance, fewer body-image cognitive distortions, less disturbed eating attitudes, and lower body mass. Moreover, greater day-to-day body-image variability was predicted by greater psychological investment in appearance, more body-image cognitive distortions, and higher perfectionistic self-presentation. Implications and future directions for research are discussed.     

Tumor necrosis factor-associated protein 1 (TRAP-1) protects cells from oxidative stress and apoptosis

TRAP-1 is a mitochondrial heat shock protein (HSP), recently identified in Saos-2 osteosarcoma cells adapted to mild oxidative stress induced by diethylmaleate (DEM). TRAP-1 mRNA expression is increased in DEM-adapted cells as well as in tumor cells resistant to 5-fluorouracil and to platin derivatives. Since a strong decrease of TRAP-1 protein levels, upon cisplatin treatment, is observed only in controls but not in the DEM-adapted counterpart, a possible role for this protein in the development of resistant phenotypes could be hypothesized. To characterize the protective role of TRAP-1 against oxidative stress and apoptosis, stable transfectants were generated and characterized for their response to different stress types. These stable clones expressing constitutively high TRAP-1 levels: (i) are more resistant to H2O2-induced DNA damage and to apoptosis by cisplatin; (ii) contain higher reduced glutathione (GSH) levels than control cells; and (iii) do not release the apoptosis-inducing factor into the nucleus upon cisplatin treatment. Furthermore, high TRAP-1 levels interfere with caspase 3 activation. These results confirm the anti-apoptotic role of TRAP-1, and suggest that increased expression of this mitochondrial HSP in DEM-adapted and chemoresistant cells could be part of a pro-survival signaling pathway aimed to evade toxic effects of oxidants and anticancer drugs.     

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.     

Dysfunctional attitudes and episodes of major depression: Predictive validity and temporal stability in never-depressed, depressed, and recovered women

In a large, community-based sample of women (N = 750), the authors examined the nature of associations between dysfunctional attitudes and depression. Dysfunctional attitudes were evaluated both as a vulnerability factor for depression and as a consequence of depression. A link was found between past depression and baseline elevations in dysfunctional attitudes that was independent of current subsyndromal symptoms, but intensification of dysfunctional attitudes following prospectively evaluated episodes of depression (depressive "scarring") was not observed. Although baseline dysfunctional attitudes predicted an episode of major depression over 3 years of prospective study, this prediction, considered alone or in interaction with negative life events, was redundant with that offered by history of past depression. Further, no significant prediction was evident for the Dysfunctional Attitude Scale (A. N. Weissman & A. T. Beck, 1978) when the formerly depressed and never-depressed cohorts were considered separately. Implications for cognitive theories are discussed.     

Facets of psychopathy, heart rate variability and cognitive function

The aim of the present study was to investigate whether the four facets of Hare's Psychopathy Checklist-Revised (PCL-R; Hare, 1991; Bolt, Hare, Vitale, & Newman, 2004) were related to physiological and cognitive mechanisms. Fifty-three male prisoners participated in this study. Physiological responses were measured as heart rate variability (HRV) and heart rate (HR). Cognitive functions were measured using a continuous performance test (CPT; California Computerized Assessment Package, Abbreviated version) and a working memory test (WMT); based on Baddeley & Hitch (1974). The regression analysis of the HRV revealed that the interpersonal facet explained most of the variance during baseline (28%), CPT (16%), and WMT (12%). This was also true for the HR data during baseline (28%), CPT (20%), WMT (10%), and recovery (13%). The antisocial facet explained 10% of the variance only during baseline. Subjects scoring high compared to low on the interpersonal facet also showed better cognitive functioning. The study suggests that the different facets were differently associated with both physiological and cognitive functions.     

Update on the decline in the education and training in psychological measurement and assessment

An update is presented on the steady decline in the education and training of psychometricians, quantitative psychologists, and personality assessment psychologists in North America.