What cognitive and numerical skills best define learning disabilities in mathematics? / ¿Qué habilidades cognitivas y numéricas definen mejor las dificultades de aprendizaje en matemáticas?

Differentiating students with mathematical learning disabilities (MLD) from those with low achievement (LA) is still an unresolved issue. This study explored whether the specific combination of certain cognitive and numerical skills can classify students with MLD, with LA, and without MLD. In order to do this, an analysis was carried out of the performance of 756 Spanish students in grades two to six, on different numerical and cognitive tasks. Two factors were extracted using a principal component analysis of the tasks: a semantic-cognitive factor and a verbal-automation factor. The results obtained from comparing the groups showed that students with MLD and LA demonstrated significant differences in the semantic-cognitive factor, and that these differences were consistent across grade levels. In contrast, there were no differences between groups in the automatic-verbal factor. These results confirm that the groups are not only quantitatively different but also qualitatively different.     

Retinal eccentricity and the detection of targets

Summary It is known that the detectability of a target depends on its similarity to the individual context elements. This article attempts to show that global properties of the context can also influence detection performance. For example, the detection of an O among several Hs appears to be easier than the detection of an H among several Os, because the context consists of elements that are more angular. However, this angular-context advantage is most apparent when the stimulus projection falls on extrafoveal areas of the retina. The results of two stimulus manipulations suggest that the decreasing ability of the visual system with increasing eccentricity could be responsible for this relationship. Increasing the distance between the single elements, and thus reducing the effect of lateral inhibition, led to a deterioration in performance; and by defocusing the stimulus presentation it was possible to achieve an improvement in performance.     

Intra-couple similarity in dyadic coping and partners’ adjustment to the birth of a child

Unlike individual perceptions of a couple's functioning, couple-level protective factors against poor adjustment to the birth of a child have rarely been studied. This study examined similarity or reciprocal exchanges in dyadic coping (DC) during pregnancy (T1) and at 6 weeks postpartum (T2) and its associations with both partners’ adjustment at 6–9 months postpartum (T3). Ninety-two Portuguese couples provided data on DC, internalizing symptoms, dyadic adjustment and parenting stress. An individual's perceived similarity at T1 positively predicted his or her own internalizing symptoms at T3. One partner's perceived similarity at T2 negatively predicted the other partner's internalizing symptoms and parenting stress at T3. These associations controlled for stereotype effects (i.e., similarity due to shared cultural norms and values). Both partners’ adjustment seems to benefit from unique similarity within the couple after childbirth, while complementarity in DC during pregnancy appears to be more beneficial in the long term. Our findings suggest important refinements to DC-based interventions already aimed to promote similarity in DC.