The Yin and Yang of cell cycle progression and differentiation in the oligodendroglial lineage

In white matter disorders such as leukodystrophies (LD), periventricular leucomalacia (PVL), or multiple sclerosis (MS), the hypomyelination or the remyelination failure by oligodendrocyte progenitor cells involves errors in the sequence of events that normally occur during development when progenitors proliferate, migrate through the white matter, contact the axon, and differentiate into myelin-forming oligodendrocytes. Multiple mechanisms underlie the eventual progressive deterioration that typifies the natural history of developmental demyelination in LD and PVL and of adult-onset demyelination in MS. Over the past few years, pathophysiological studies have mostly focused on seeking abnormalities that impede oligodendroglial maturation at the level of migration, myelination, and survival. In contrast, there has been a strikingly lower interest for early proliferative and differentiation events that are likely to be equally critical for white matter development and myelin repair. This review highlights the Yin and Yang principles of interactions between intrinsic factors that coordinately regulate progenitor cell division and the onset of differentiation, i.e. the initial steps of oligodendrocyte lineage progression that are obviously crucial in health and diseases.     

Attention between phenomenology and experimental psychology

It is possible to consider attention as the modulating dimension of consciousness. Understood in this sense, attention can be a privileged theme for relating the first person point of view (conceived as a psycho-phenomenology inspired by the work of Husserl) to the experimental sciences (e.g. psychology, neuropsychology, etc.), which have done a great deal of work on attention. This article will take up in succession some different points of view regarding the status of attention and its structure (e.g. static aspects). It will also consider the dynamic of attention from a micro-genetic point of view as well as a functional point of view. The final section will seek to show not only the unique and original contributions of each perspective, but also each perspective's limitations and biases.     

Assessing personality at risk in personnel selection and development

This paper demonstrates the validity and usefulness of a count technique to screen for potential personality dysfunctioning in NEO‐PI‐R ratings obtained in selection and professional development assessments. The usefulness of this screening technique for Industrial, Work and Organizational (IWO) psychologists is demonstrated in five different samples that were administered the NEO‐PI‐R for selection or development purposes. Three additional samples served as normative data to compute FFM PD count cut‐offs that can be used for selection and career development decisions. Evidence for the construct validity of 6 out of 10 FFM PD counts was provided, and all FFM PD compound scales were significantly related to important criteria, including the final selection decision, the results of a behaviourally oriented selection interview and self‐rated work competencies. The practical utility and limitations of this count technique for personnel selection and development are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Item performance in visual word recognition

Standard factorial designs in psycholinguistics have been complemented recently by large-scale databases providing empirical constraints at the level of item performance. At the same time, the development of precise computational architectures has led modelers to compare item-level performance with item-level predictions. It has been suggested, however, that item performance includes a large amount of undesirable error variance that should be quantified to determine the amount of reproducible variance that models should account for. In the present study, we provide a simple and tractable statistical analysis of this issue. We also report practical solutions for estimating the amount of reproducible variance for any database that conforms to the additive decomposition of the variance. A new empirical database consisting of the word identification times of 140 participants on 120 words is then used to test these practical solutions. Finally, we show that increases in the amount of reproducible variance are accompanied by the detection of new sources of variance.     

Ignorance,Knowledge, and Two Epistemic Intuitions

Philosophia - One of the most venerable and enduring intuitions in epistemology concerns the relationship between true belief and knowledge. Famously articulated by Socrates, it holds that true...     

Motivation to hide emotion and children's understanding of the distinction between real and apparent emotions

The authors investigated the extent to which children's understanding of the distinction between real and apparent emotions varied according to the motivation to hide emotions. Children, aged 6-7 and 10-11 years, were read stories designed to elicit either prosocial or self-protective motivated display rules and were asked to predict the facial expressions the protagonists would make to hide felt emotions. Children were found to understand the distinction between real and apparent emotions very well, independently of the type of motivation. Contrary to predictions, boys understood this distinction better than did girls when the motivation to hide positive emotions was prosocial. Children perceived neutralization as the most appropriate strategy to hide felt emotions, followed by masking.     

Discrimination of English and French orthographic patterns by biliterate children

We investigated whether young English–French biliterate children can distinguish between English and French orthographic patterns. Children in French immersion programs were asked to play a dictionary game when they were in Grade 2 and again when they were in Grade 3. They were shown pseudowords that contained either an English spelling pattern or a French spelling pattern, and they were asked to decide whether each pseudoword should go in an English dictionary or a French dictionary if it became a real word. Comparison groups of monolingual English children, monolingual French children, and English–French bilingual university students were also tested on the task. French immersion students in both grades were above chance in discriminating between the two types of pseudowords but were well below adult performance on the task. Measures obtained in kindergarten showed that early print knowledge had some ability to predict later ability to discriminate between the orthographic patterns of the two languages. Further analyses indicated that exposure to print in each language in Grades 1 to 3 was strongly related to discrimination performance. The findings are interpreted as being consistent with the statistical learning hypothesis.     

Learning nonadjacent dependencies: no need for algebraic-like computations

Is it possible to learn the relation between 2 nonadjacent events? M. Pena, L. L. Bonatti, M. Nespor, and J. Mehler (2002) claimed this to be possible, but only in conditions suggesting the involvement of algebraic-like computations. The present article reports simulation studies and experimental data showing that the observations on which Pena et al. grounded their reasoning were flawed by deep methodological inadequacies. When the invalid data are set aside, the available evidence fits exactly with the predictions of a theory relying on ubiquitous associative mechanisms. Because nonadjacent dependencies are frequent in natural language, this reappraisal has far-reaching implications for the current debate on the need for rule-based computations in human adaptation to complex structures.     

Encoding numbers: Behavioral evidence for processing-specific representations

The aim of this study was to test the hypothesis of a complex encoding of numbers according to which each numerical processing requires a specific representational format for input In three experiments, adult participants were given two numbers presented successively on screen through a self-presentation procedure after being asked to add, to subtract, or to compare them. We considered the self-presentation time of the first number as reflecting the complexity of the encoding for a given planned processing. In line with Dehaene's triple-code model, self-presentation times were longer for additions and subtractions than for comparisons with two-digit numbers but longer for subtractions than for additions and comparisons with one-digit numbers. The implications of these results for different theories of number processing are discussed.     

Recognition thresholds for plane-rotated pictures of familiar objects

We investigated picture plane rotation effects on the minimum stimulus duration required to recognise pictures of familiar objects in a picture-word verification task. Participants made unspeeded responses, selecting from 126 written alternatives. Longer stimulus durations were needed to identify plane-misoriented views. These orientation effects were non-linear, arguing against a simple mental rotation account of compensation for plane misorientation in identification tasks. Orientation effects were found for almost all items, in particular including those labelled at the basic level (cf. Hamm, McMullen, 1998, Journal of Experimental Psychology: Human Perception and Performance 24, 413-426). We suggest that plane misorientation increases the difficulty of basic level as well as subordinate level identification unless only a small, visually dissimilar set of stimuli are presented. Errors in the task were analysed to provide an alternative, objective measure of perceived visual similarity, by assessing the number and nature of mistaken identifications made to a given target object. We propose that misorientation effects are best understood in terms of the effects of the perceived visual similarity of a target to its set of response alternatives rather than in terms of the level (basic or subordinate) at which the target is to be identified.