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Previous studies measuring looking-time suggested that already infants possess intuitive knowledge about physical support. The aim of the present study was to investigate whether children were able...

Previous research suggested that performance in spatial judgments involving rotated human figures is poorer if these figures are presented from the front than from the back. We further investigated this effect, controlling for visible facial information in front and back view by presenting figures' faces as profile. Children's and adults' judgments were still faster and less error prone if figures were presented from the back. Moreover, reaction times indicated that participants did not mentally rotate figures in front view. Children performed overall more poorly than adults, but there were also qualitative differences suggesting that children are more susceptible to embodiment effects than adults. This study underlines that embodiment may have differential effects in spatial transformation tasks, enhancing or impairing performance.

Based on violation-of-expectation (VoE) paradigms, amazing cognitive competencies have been demonstrated in young infants, which could not be shown in toddlers or even preschoolers. This divergence might as much be caused by different research methods as by discontinuities in development. As looking-time measures are not readily applicable to older children, we suggest a new method that is suitable for children from two years of age onwards. In an empirical examination of this method, 26 children aged 2–7 years learned by trial and error to always find a target picture among a pair of pictures. Each target picture was an impossible version of the non-target picture. After reaching a learning criterion, children had to generalize the learned concept to pictures belonging to a different category. Results showed that even the youngest participants reached the learning criterion and were able to apply what they had learned to another category.

Motor influences on the mental transformation of body parts have been observed in both children and adults. Previous findings indicated that these influences were more pronounced in children than in adults, suggesting a stronger link between motor processes and imagery in children. The present series of two experiments casts doubt on the general validity of such an interpretation. Kindergartners' (aged 5–6 years), first graders' (aged 7 years), and adults' performance in the mental rotation of pictures of body parts was monitored for influences of internal representations of motor constraints (motor effect). In both experiments, evidence for mental rotation was obtained for each group. Unexpectedly, kindergarten boys made significantly more errors than kindergarten girls. A motor effect was only found in the second experiment, where it was least pronounced in the youngest age group. Our results suggest that mental transformations of body parts do not necessarily involve motor processes and that embodiment...

The neuronal stem cell leukemia (NSCL) basic helix-loop-helix factors are neural cell-specific transcription factors. We have disrupted the NSCL-1 gene by homologous recombination and replaced the coding region with a beta-galactosidase reporter cassette to study the role of NSCL-1 in neuronal development and to follow the fate of NSCL-1 mutant cells. NSCL-1 mutant mice are viable and fertile on various genetic backgrounds and do not show any obvious signs of neurological malfunction. No differences in the distribution of NSCL-1 mutant or heterozygous neuronal cells were observed in the diencephalon, hippocampus, neocortex, and cerebellum at different stages of development. Likewise, no defects were found in the laminar organization of the cortex, and the distinct neuronal subpopulation appeared normal during development of the neocortex. Analysis of sensory neurons which strongly express NSCL-1 revealed that the spatiotemporal expression of neuronal differentiation factors, such as NeuroD and SCG-10, was not altered in developing distal and proximal cranial ganglia of mutant mice. In the cerebellum expression of NSCL-1 was confined to the proliferative and premigratory zone of the external granular layer and the internal granular layer. Interestingly, unlike cerebella of Math1(-/-) or NeuroD2(-/-) mice, NSCL-1-deficient mice have no obvious developmental defect, and neurons of the cerebellum appeared fully differentiated. Despite similar expression patterns of NSCL-1 and NSCL-2 in various areas of the diencephalon, including the arcuate nucleus and paraventricular nucleus, NSCL-1(-/-) mice are fertile and show no adult onset of obesity like NSCL-2 mutant mice. Double-mutant NSCL-1(-/-)-NSCL-2(-/-) mice do not show any additional obvious malformations of the central nervous system, although both genes are expressed in a largely overlapping pattern. Our results argue against a simple functional redundancy within the NSCL gene family.