Numerical and nonnumerical estimation in children with and without mathematical learning disabilities

There are currently multiple explanations for mathematical learning disabilities (MLD). The present study focused on those assuming that MLD are due to a basic numerical deficit affecting the ability to represent and to manipulate number magnitude (Butterworth, 1999 Butterworth, B. 1999. The mathematical brain, London, , United Kingdom: Macmillan.  [Google Scholar], 2005 Butterworth, B. 2005. “Developmental dyscalculia”. In Handbook of mathematical cognition, Edited by: Campbell, J. I. D. 455–467. New York, NY: Psychology Press.  [Google Scholar]; A. J. Wilson &; Dehaene, 2007 Wilson, A. J. and Dehaene, S. 2007. “Number sense and developmental dyscalculia”. In Human behavior, learning, and the developing brain: Atypical development, 2nd, Edited by: Coch, D., Dawson, G. and Fischer, K. 212–237. New York, NY: Guilford Press.  [Google Scholar]) and/or to access that number magnitude representation from numerical symbols (Rousselle &; Noël, 2007 Rousselle, L. and Noël, M. P. 2007. Basic numerical skills in children with mathematics learning disabilities: A comparison of symbolic vs non-symbolic number magnitude processing. Cognition, 102(3): 361–395. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). The present study provides an original contribution to this issue by testing MLD children (carefully selected on the basis of preserved abilities in other domains) on numerical estimation tasks with contrasting symbolic (Arabic numerals) and nonsymbolic (collection of dots) numbers used as input or output. MLD children performed consistently less accurately than control children on all the estimation tasks. However, MLD children were even weaker when the task involved the mapping between symbolic and nonsymbolic numbers than when the task required a mapping between two nonsymbolic numerical formats. Moreover, in the estimation of nonsymbolic numerosities, MLD children relied more than control children on perceptual cues such as the cumulative area of the dots. Finally, the task requiring a mapping from a nonsymbolic format to a symbolic format was the best predictor of MLD. In order to explain these present results, as well as those reported in the literature, we propose that the impoverished number magnitude representation of MLD children may arise from an initial mapping deficit between number symbols and that magnitude representation.     

Production of lexical categories in French children with SLI and in normally developing children matched for MLU

Free speech recording samples of two groups of French SLI children aged 48 and 62 months (matched for MLU, 1.70) and two groups of French normally developing children aged 26 and 36 month (matched for MLU, 3.2) were compared to determine whether they showed a difference in the use of lexical categories. A category-by-category comparison showed few significant differences. For low MLU children, SLI produced significantly fewer infinitives, past participles, copulas, and demonstrative pronouns. For high MLU children, the difference persisted only in past participles use. As for English SLI children, French SLI children were delayed in their acquisition of verbs. However, the differences in the syntactic structure of English and French ruled out a syntactic explanation of the deficit. Phonetic problems seem to decrease with age, so they cannot be the only explanation behind the difficulties of SLI children, which probably involve cognitive problems such as processing limitations.     

Experts and laymen grossly underestimate the benefits of argumentation for reasoning

Many fields of study have shown that group discussion generally improves reasoning performance for a wide range of tasks. This article shows that most of the population, including specialists, does not expect group discussion to be as beneficial as it is. Six studies asked participants to solve a standard reasoning problem—the Wason selection task—and to estimate the performance of individuals working alone and in groups. We tested samples of U.S., Indian, and Japanese participants, European managers, and psychologists of reasoning. Every sample underestimated the improvement yielded by group discussion. They did so even after they had been explained the correct answer, or after they had had to solve the problem in groups. These mistaken intuitions could prevent individuals from making the best of institutions that rely on group discussion, from collaborative learning and work teams to deliberative assemblies.     

The Longitudinal Interplay of Adolescents' Self-Esteem and Body Image: A Conditional Autoregressive Latent Trajectory Analysis

Suppose P_I and P₂ are two competing discrimination procedures. 1Co com-, its are pare the relative discriminatory power of both procedures, test statistics are suggested for the hypothesis that P_l and P₂ performed no better than, random assignment versus the alternative that P₁ did significantly better than P_e.     

A general area theorem for the same—different paradigm

According to a well-known theorem in psychophysics (Green & Swets, 1966), the area under the receiver operating characteristic (ROC) for the yes—no paradigm equals the proportion of correct responses of an unbiased observer in the two-interval, two-alternative, forced choice paradigm (2I2AFC). Here, we demonstrate a similar relationship between the ROC area in the two-interval same—different (AX or 2IAX) paradigm, and the proportion correct in the four-interval same—different (4IAX, also known as dual-pair comparison) paradigm. The theorem demonstrated here is general, in the sense that it does not require that the sensory observations have a specific distribution (e.g., Gaussian), or that they be statistically independent.     

Active tuberculosis detection by pouched rats in 2014: More than 2,000 new patients found in two countries

Tuberculosis (TB) is a major problem in poor countries because sensitive diagnostic tools are unavailable. In 2014, our pouched rats evaluated sputum from 21,600 Tanzanians and 9,048 Mozambicans whose sputum had previously been evaluated by microscopy, the standard diagnostic for TB. Evaluation by the rats revealed 1,412 new patients with active TB in Tanzania and 645 new patients in Mozambique, increases of 39% and 53%, respectively, when compared to detections by microscopy alone. These results provide further support for the applied use of scent‐detecting rats.     

Self-esteem, self-confidence, anxiety and claimed self-handicapping: A mediational analysis

Objectives

The purpose of the present study was to examine the mediational role of self-confidence and anxiety in the relationship between self-esteem and claimed self-handicapping in an achievement context.

Design

To test this mediational role, the three-step procedure advocated by Baron and Kenny (1986) was used.

Method

After hearing and reading about specific conditions of performing that were intended to favor invoking excuses for future poor performance, 68 competitive basketball players completed measures of self-esteem, anxiety (cognitive and somatic), self-confidence, and claimed self-handicapping. Then, they warmed-up and carried out a basketball task.

Results

Self-esteem negatively predicted cognitive anxiety and positively predicted self-confidence. In turn, self-confidence negatively predicted claimed self-handicapping and mediated the relationship between self-esteem and claimed self-handicapping. Cognitive and somatic anxieties did not mediate the relationship between self-esteem and claimed self-handicapping. Together, these results suggest that individuals with low self-esteem use more claimed self-handicaps because they have lower self-confidence.

Conclusion

These findings shed light on the psychological processes that lead people with low self-esteem to use strategies of claimed self-handicaps.     

Externalizing behavior trajectories: The role of parenting, sibling relationships and child personality

Based on longitudinal multilevel modeling and using a multi-informant strategy, this study examines trajectories of externalizing problem behavior (EPB) in childhood as predicted by parental behavior (absolute level of parenting [ALP] and parental differential treatment [PDT]), parental self-efficacy (PSE), child personality and sibling relationships. Besides main effects, several interactions were tested. The effects of changes in parenting on changes in EPB were also examined. A total of 119 families from the French-speaking area of Belgium rearing a child (3- to 5-year-olds at the onset of the study) referred for EPB were studied. The effects of both level-of and changes-in mothers' ALP were partially confirmed, but for fathers, only ALP was predictive. There were some significant interactions between ALP and PDT for both parents. Mothers' PSE explained some variance in EPB, additional to that explained by the parenting measures. Some parenting by personality and by sibling relationship interactions were found.     

Holographic string encoding

In this article, we apply a special case of holographic representations to letter position coding. We translate different well-known schemes into this format, which uses distributed representations and supports constituent structure. We show that in addition to these brain-like characteristics, performances on a standard benchmark of behavioral effects are improved in the holographic format relative to the standard localist one. This notably occurs because of emerging properties in holographic codes, like transposition and edge effects, for which we give formal demonstrations. Finally, we outline the limits of the approach as well as its possible future extensions.     

Geographic region effects on adolescent physical self: An exploratory study

The objectives of this exploratory study were to examine gender differences in physical self‐concept, and the influence of geographic place of residence on both adolescents' physical self‐concept and gender differences in physical self‐concept. The Physical Self Inventory was used to measure physical self‐perceptions and global self‐esteem. Participants were 323 boys and 282 girls living in the North or South of France. First a Mann‐Whitney U test was used to assess gender differences and the influence of geographic region differences on physical self‐perceptions (physical self‐worth, physical condition, sport competence, attractive body, physical strength) and global self‐esteem. Then a Kruskal‐Wallis ANOVA for ranked data was used to assess geographic region influence on boys' and girls' physical self‐concept and global self‐esteem. The results showed that not only did boys have significantly higher physical self scores (on all scales) and global self‐esteem than girls, but also that adolescents from the North of France had higher physical self scores (on all scales) and global self‐esteem than adolescents from the South. Moreover, many differences were found between boys and girls on physical self scores (on all scales) and global self‐esteem according to their geographic place of residence. The main results showed that girls from the South had lower scores on the attractive body, physical strength, physical self‐worth, and global self‐esteem scales than all other adolescents, and that boys from the South had lower scores on the attractive body and global self‐esteem scales than did boys and girls from the North.