Inhibitory control and verb inflection in Italian preschool children.

The study investigates whether Italian verbal inflectional morphology is associated with inhibitory control skills after controlling for receptive vocabulary and verbal working memory. A sample of Italian preschoolers aged 4;0 to 6;0 was assessed using a standardized inhibitory control task tapping two different inhibitory skills (response inhibition and interference suppression), and a morphological task requiring simple and complex inflections of verbs. The hierarchical multiple regression analyses showed that working memory and the interference suppression scores were significantly associated with complex inflections but not with simple inflections of the verbs.

A working memory span task for toddlers.

This study presents a new working memory measure for toddlers, inspired by the Spin-the-Pots (Hughes & Ensor, 2005), which we modified structuring it as a memory span task. As in the original task, we required toddlers to retrieve objects hidden in little boxes; however, in our Memory Span Spin-the-Pots (MSSP) we used smaller numbers of targets, and we systematically manipulated memory load, covering or not the display, and rotating it or not. Two experiments involved participants between 18 months and three years. In Experiment 1 we examined the effects of covering and rotation on toddlers' memory. Either covering or rotating the stimuli hindered their performance, and combining both transformations yielded an under-additive interaction. Moreover, the effect of covering decreased in the second half of the procedure. In Experiment 2 we validated the MSSP as a working memory measure by comparing it with the Imitation Sorting Task (IST; Alp, 1994). We found that the MSSP correlated with the IST, also with age partialled out, although the IST was easier. In both experiments, the scores increased with age. Overall, this research sheds light on some variables that affect toddlers' performance on the MSSP, and shows that it can be used as a valid working memory measure for toddlers. The results are discussed considering the attentional processes presumably involved.

The relationship between temperamental dimensions and inhibitory control in early childhood: Implications for language acquisition.

The present study investigates the latent organization of inhibitory control in children aged between 2;3 and 3;0 years. In addition, it explores the relationships between temperament dimensions - social orientation, motor activity, and attention -, inhibitory control and language. One-hundred-twelve typically developing children were evaluated with tasks for inhibitory control and lexical skills, while ratings of temperament and language were collected from their caregivers. A Confirmatory Factor Analysis reveals that inhibitory control seems to be best described by a unitary dimension. A Structural Equation Model suggests that 78 % of the variance in vocabulary is explained by a model considering the language observed measures, the three temperamental dimensions, and inhibitory control and in which both temperamental attention and the latent dimension of inhibitory control are significantly related to vocabulary. In addition, inhibitory control does not mediate the relationship between temperament and language.

Inhibitory processes in toddlers: a latent-variable approach.

The aim of this study was to investigate the nature of inhibitory processes in early childhood. A confirmatory factor analysis was used to examine the latent structure of inhibitory processes in day-care center children aged 24-32 months and in preschool children aged 36-48 months. The best fit to the data for the younger sample was a single undifferentiated inhibition factor model; in older children, a two-factor model was differently identified in which response inhibition and interference suppression were distinguished.