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A number of training interventions have been designed to improve executive functions and inhibitory control (IC) across the lifespan. Surprisingly, no study has investigated the structural neuroplasticity induced by IC training from childhood to late adolescence, a developmental period characterized by IC efficiency improvement and protracted maturation of prefrontal cortex (PFC) subregions involved in IC. The aim of the present study was to investigate the behavioral and structural changes induced by a 5-week computerized and adaptive IC training in school-aged children (10-year-olds) and in adolescents (16-year-olds). Sixty-four children and 59 adolescents were randomly assigned to an IC (i.e. Color-Word Stroop and Stop-Signal tasks) or an active control (AC) (knowledge- and vocabulary-based tasks) training group. In the pre- and posttraining sessions, participants performed the Color-Word Stroop and Stop-signal tasks, and an anatomical resonance imaging (MRI) was acquired for each of them. Children's IC efficiency improved from the pre- to the posttraining session in boys but not in girls. In adolescents, IC efficiency did not improve after IC training. Similar to the neuroplastic mechanisms observed during brain maturation, we observed IC training-related changes in cortical thickness and cortical surface area in several PFC subregions (e.g. the pars opercularis, triangularis, and orbitalis of the inferior frontal gyri) that were age- and gender-specific. Because no correction for multiple comparisons was applied, the results of our study provide only preliminary evidence of the complex structural neuroplastic mechanisms at the root of behavioral changes in IC efficiency from pre- to posttraining in school-aged children and adolescents.

To act and think, children and adults are continually required to ignore irrelevant visual information to focus on task-relevant items. As real-world visual information is organized into structures, we designed a feature visual search task containing 3-level hierarchical stimuli (i.e., local shapes that constituted intermediate shapes that formed the global figure) that was presented to 112 participants aged 5, 6, 9, and 21 years old. This task allowed us to explore (a) which level is perceptively the most salient at each age (i.e., the fastest detected level) and (b) what kind of attentional processing occurs for each level across development (i.e., efficient processing: detection time does not increase with the number of stimuli on the display; less efficient processing: detection time increases linearly with the growing number of distractors). Results showed that the global level was the most salient at 5 years of age, whereas the global and intermediate levels were both salient for 9-year-olds and adults. Interestingly, at 6 years of age, the intermediate level was the most salient level. Second, all participants showed an efficient processing of both intermediate and global levels of hierarchical stimuli, and a less efficient processing of the local level, suggesting a local disadvantage rather than a global advantage in visual search. The cognitive cost for selecting the local target was higher for 5- and 6-year-old children compared to 9-year-old children and adults. These results are discussed with regards to the development of executive control.

We investigated whether success in number-conservation and class-inclusion tasks relies on a general ability to inhibit misleading strategies. Two groups of 10-year-olds performed inter-task priming between computerized versions of class-inclusion and number-conservation tasks (Experiment 1). In one group, the class-inclusion task served as a prime and the number-conservation task as an assessment probe and vice versa in the other group. Response times were shorter in the number-conservation task when performed after the class-inclusion task (and vice versa in the other group) than in control prime-probe sequences in which the primes did not require the inhibition of a misleading strategy. Experiment 2 showed that these inter-task priming effects did not simply reflect that class inclusion and number conservation rely on the reversibility of concrete operations as Piaget would have hypothesized. Taken together the results are consistent with the neo-Piagetian assumption that cognitive development is rooted in both the acquisition of knowledge of incremental complexity and the ability to resist (inhibit) previous knowledge. Critically, the present finding suggests that the inhibitory ability is not domain- or strategy-specific. (Contains 3 tables and 4 figures.)

Our previous studies provide some evidence of between-language effects on arithmetic performance in 2-year-olds. French-speaking children were especially biased by the use of the word "un" as a cardinal value and as an article in the singular/plural opposition (1 vs. the set 2, 3, ...). Here we evaluated the ability of a new action-based assessment method to avoid this bias. A total of 80 French-speaking 2- and 3-year-olds were confronted with impossible (1 + 1 = 1 or 1 + 1 = 3) and possible (1 + 1 = 2) addition problems that triggered the bias. The problems were either presented to the children by the experimenter (onlooker mode) or realized by themselves (actor mode). The 2-year-olds performed better in the actor mode than in the onlooker mode. A subtraction control with no language ambiguity (2-1 = 2 or 1) was conducted with 80 other children; both modes elicited comparable performances regardless of age. These data indicate that the actor mode is effective for assessing arithmetic ability in French-speaking 2-year-olds. (Contains 1 table and 5 figures.)

This study investigated how global and local perceptual processes evolve during childhood according to the meaningfulness of the stimuli. Children had to decide whether visually presented pairs of items were identical or not. Items consisted of global forms made up of local forms. Both global and local forms could represent either objects or nonobjects. In dissimilar pairs, items differed at one level (target level), while the other level included similar forms on both sides (irrelevant level). The results indicate an evolution from local preference at 4 years of age to adult-like global preference at 9 years of age. Moreover, as previously reported in adults, regardless of age, identification impaired performance when the irrelevant level was made of objects and the target level was made of nonobjects (interference). However, in younger children, this interference existed even when objects were present at all levels, suggesting that the strategy used to perform the comparison task also varied according to age.