Children inhibit global information when the forest is dense and local information when the forest is sparse

Effects of general anaesthesia in early childhood on local and global visual processing: a post hoc analysis of the APEX cohort study

BACKGROUND

Preclinical studies suggest that early exposure to anaesthesia alters the visual system in mice and non-human primates. We investigated whether exposure to general anaesthesia leads to visual attention processing changes in children, which could potentially impact essential life skills, including learning.

METHODS

This was a post hoc analysis of data from the APprentissages EXécutifs et cerveau chez les enfants d'âge scolaire (APEX) cohort study. A total of 24 healthy 9-10-yr-old children who were or were not exposed to general anaesthesia (for surgery) by a mean age of 3.8 (2.6) yr performed a visual attention task to evaluate ability to process either local details or general global visual information. Whether children were distracted by visual interference during global and local information processing was also assessed.

RESULTS

Participants included in the analyses (n=12 participants exposed to general anaesthesia and n=12 controls) successfully completed (>90% of correct answers) the trial tasks. Children from both groups were equally distracted by visual interference. However, children who had been exposed to general anaesthesia were more attracted to global visual information than were control children (P=0.03).

CONCLUSIONS

These findings suggest lasting effects of early-life exposure to general anaesthesia on visuospatial abilities. Further investigations of the mechanisms by which general anaesthesia could have delayed effects on how children perceive their visual environment are needed.

A Systematic Review on Visual-Processing Deficits in Neurofibromatosis Type 1: What Possible Impact on Learning to Read?

This systematic review aimed to examine the possible implication of visual-perceptual, visuo-attentional and oculomotor processing in the reading deficits frequently experienced by children with Neurofibromatosis type 1 (NF1), as previously shown in dyslexia. Using PRISMA methodological guidelines, we examined 49 studies; most of these reported visual-processing deficits in this population, raising the importance of directly studying the visuo-perceptual and visuo-attentional processes and eye-movement control involved in the learning-to-read process in NF1. The discussion provides a reflection for a better understanding of how visual-processing skills interact with reading deficits in NF1, as well as new avenues for their screening and care.

Development of local-global preference in vision and haptics

We aimed to advance our understanding of local-global preference by exploring its developmental path within and across sensory modalities: vision and haptics. Neurotypical individuals from six years of age through adulthood completed a similarity judgement task with hierarchical haptic or visual stimuli made of local elements (squares or triangles) forming a global shape (a square or a triangle). Participants chose which of two probes was more similar to a target: the one sharing the global shape (but different local shapes) or the one with the same local shapes (but different global shape). Across trials, we independently varied the size of the local elements and that of the global configuration-the latter was varied by manipulating local element density while keeping their numerosity constant. We found that the size of local elements (but not global size) modulates the effects of age and modality. For stimuli with smaller local elements, the proportion of global responses increased with age and was similar for visual and haptic stimuli. However, for stimuli made of our largest local elements, the global preference was reduced or absent, particularly in haptics, regardless of age. These results suggest that vision and haptics progressively converge toward similar global preference with age, but residual differences across modalities and across individuals may be observed, depending on the characteristics of the stimuli.

Neurobehavioral Phenotype and Dysexecutive Syndrome of Preterm Children: Comorbidity or Trigger? An Update

Premature birth is a worldwide public health priority. One in ten children is born before 37 weeks of gestational age and, in developed countries, survival rates without major neonatal morbidity are increasing. Although severe sequelae associated with these births have decreased, their neurobehavioral difficulties, often associated in multiple fields, remain stable but still widespread. These neurobehavioral difficulties hamper the normal development of academic achievements and societal integration and intensify the children's needs for rehabilitation during their preschool and academic years. Severe sequelae increase when gestational age decreases. This is even truer if the socio-cultural background is impeded by low income, education and language skills as compared with defined averages. However, moderate and/or minor neurocognitive and/or behavioral difficulties are almost identical for a moderate or a late preterm birth. Obtaining a better clinical description of neurobehavioral characteristics of those pretermly born, once they reach preschool age, is essential to detect behavioral issues as well as early specific cognitive difficulties (working memory, planning, inhibition, language expression and reception, attention and fine motor skills, etc.). Such information would provide a better understanding of the executive functions' role in brain connectivity, neurodevelopment and neuroanatomical correlation with premature encephalopathy.

Inhibitory Abilities in Individuals with Down Syndrome: Investigation of Interference Suppression Using an Adapted Version of Navon Task

Only a few studies have investigated inhibitory sub-components in individuals with Down syndrome (DS). This study investigates interference suppression, through global-local processes, in 50 people with DS matched for mental age (MA) with 63 typically developing children (MA = 23.6 and 6.8 years respectively). We adapted and administered a non-verbal Navon-shape task with high-familiarity symbols. For both groups, results showed equal performance on global vs. local items in the congruent condition, whereas significantly better performance on global conditions when faced with incongruent items. A greater impairment in incongruent responses emerged for both groups and more so for individuals with DS.

Children's scale errors and object processing: Early evidence for cross-cultural differences

Scale errors are observed when young children make mistakes by attempting to put their bodies into miniature versions of everyday objects. Such errors have been argued to arise from children's insufficient integration of size into their object representations. The current study investigated whether Japanese and UK children's (18-24 months old, N = 80) visual exploration in a categorization task related to their scale error production. UK children who showed greater local processing made more scale errors, whereas Japanese children, who overall showed greater global processing, showed no such relationship. These results raise the possibility that children's suppression of scale errors emerges not from attention to size per se, but from a critical integration of global (i.e., size) and local (i.e., object features) information during object processing, and provide evidence that this mechanism differs cross-culturally.

The forest, the trees, and the leaves in preterm children: the impact of prematurity on a visual search task containing three-level hierarchical stimuli

Very preterm (VPT; < 33 gestational weeks) children are at risk of developing visuospatial deficits, including local/global attention deficits. They are also more likely to develop poorer inhibitory control. Here, we investigated, using the same stimuli, the potential local/global attention and inhibitory control deficits of VPT children using three levels compound stimuli (global, intermediate, and local levels), more ecological than the ones used in a classic global/local task (Navon task). We compared the results from 22 VPT children to those of a control group of 21 children to investigate (1) how VPT children processed compound stimuli with three-level information and (2) how inhibitory control in a visual task differs between VPT and control children. The results revealed that VPT children had no difficulty processing information presented at the local level. By contrast, VPT children were impaired when considering the intermediate and global levels of processing in comparison to control children. Finally, a reduced efficiency in VPT children in inhibiting visual distractors was evidenced for the conditions with a larger number of distractors. These results are discussed in terms of neurodevelopmental disorders of both dorsal stream (global visual processing) and prefrontal regions (inhibitory control) in VPT children. Given the central role of visuospatial and inhibitory control in day-to-day situations, the present results provide important clues for pedagogical implications regarding the organization of visual information presented to VPT children.

Switching between the Forest and the Trees: The Contribution of Global to Local Switching to Spatial Constructional Abilities in Typically Developing Children

Background: Spatial analysis encompasses the ability to perceive the visual world by arranging the local elements (“the trees”) into a coherent global configuration (“the forest”). During childhood, this ability gradually switches from a local to a global precedence, which contributes to changes in children’s spatial construction abilities, such as drawing or building blocks. At present, it is not clear whether enhanced global or local processing or, alternatively, whether switching between these two levels best accounts for children’s spatial constructional abilities. Methods: We assessed typically developing children 7 to 8 years old on a global/local switching task and on two widely used spatial construction tasks (the Rey–Osterrieth Complex Figure and the Block Design test). Results: The ability to switch from global to local level, rather than a global or a local advantage, best accounted for children’s performance on both spatial construction tasks. Conclusions: The present findings contribute to elucidate the relationship between visual perception and spatial construction in children showing that the ease with which children switch perception from global to local processing is an important factor in their performance on tasks requiring complex drawing and block assembling.

Shyness and perceived monitoring by peers affect children's performance in a divided attention task

To engage effectively in a dynamic social world, children must be prepared to process incoming information quickly and efficiently. For some, the perception that one may be evaluated by peers may directly affect how they attend to and engage with the world around them. The current study examined how children's performance on a hierarchical figures task varies under perceived social and nonsocial conditions as a function of temperamental shyness. A total of 78 8-year-olds completed a self-report measure of shyness and two blocks of a divided attention task in which they identified targets appearing at the global or local level of a hierarchical figure. Children completed one block under standard laboratory conditions (Baseline condition) and completed the other block under the impression that their performance was being recorded and would be shown to other children of the same age (Social Monitoring condition). Results showed that children were faster and more accurate when targets appeared at the global level and when targets remained at the same level across trials. Furthermore, as shyness increased, children responded slower in the Social Monitoring condition relative to the Baseline condition. Notably, these changes in response time were not reflected by commensurate increases in accuracy. Potential processes and motivations underlying these differences in performance, as well as implications for children in real-world situations, are discussed.