"Picture this from there": spatial perspective-taking in developmental visuospatial disorder and developmental coordination disorder.

Introduction: Either Developmental Visuospatial Disorder (DVSD) and Developmental Coordination Disorder (DCD) present with difficulties in visuospatial processing, even though entailing different degrees of impairment. Among the visuospatial domain, spatial perspective taking is essential to interact with the environment and is significantly involved in many daily activities (e.g., environment navigation and spatial orienting). Notwithstanding, no previous studies have investigated this spatial domain in children with DVSD and limited evidence is available regarding DCD. Consistent with a transdiagnostic approach, the first goal of the present study was to compare spatial perspective taking abilities of these groups, also including a control group of not diagnosed peers (ND). Secondly, the role of different fine-motor and visuo-spatial predictors on the spatial perspective taking performance was considered. Method: A total of 85 participants (DVSD = 26; DCD = 26; ND = 33), aged between 8 and 16 years old, were included in the study. Tasks assessing spatial perspective taking, fine-motor, visual imagery, and mental rotation skills, as well as visuo-spatial working memory were administered. Results and Discussion: Overall, our results confirmed weaknesses in spatial perspective taking in both clinical groups, with the DVSD obtaining the lowest scores. Similarities and differences in the predictors accounting for the performance in the spatial perspective taking task emerged, suggesting the possible employment of different fine-motor or visuospatial strategies by group. Findings are discussed considering the potential impact they may have both in research and clinical practice.

Trajectory assessments of cognitive, visuospatial, and academic profile in nonverbal learning disability (visuospatial developmental disorder).

Substantial progress has been made in defining children with nonverbal learning disability (NLD), but longitudinal studies are still lacking. To start filling this gap, we examined changes in general cognitive functioning, visuo-constructive skills, and academic profiles in a group of children with NLD, also taking into account any internalizing and externalizing symptom as transdiagnostic features. A total of 30 participants (24 boys) diagnosed with NLD were tested twice, with a three-year gap between the two assessments (T1: at age 8-13; T2: at 11-16), on their cognitive profile, visuospatial abilities, and academic performance (i.e., reading, writing and arithmetic abilities). At T2, any internalizing and externalizing symptom was also investigated. Statistically significant differences emerged between the two assessments in terms of the WISC-IV Perceptual Reasoning Index (PRI), handwriting speed and arithmetical fact retrieval. The NLD profile seems to be characterized by a relative stability in its core features during a child's development, as regards both weaknesses (i.e., visuospatial processing) and strengths (i.e., verbal abilities). The presence of internalizing and externalizing symptoms also suggested the importance to analyze transdiagnostic features rather than only sharp boundaries between conditions.

Resting State Dynamic Reconfiguration of Spatial Attention Cortical Networks and Visuospatial Functioning in Non-Verbal Learning Disability (NVLD): A HD-EEG Investigation.

Nonverbal learning disability (NVLD) is a neurodevelopmental disorder characterized by deficits in visuospatial processing but spared verbal competencies. Neurocognitive markers may provide confirmatory evidence for characterizing NVLD as a separate neurodevelopmental disorder. Visuospatial performance and high-density electroencephalography (EEG) were measured in 16 NLVD and in 16 typically developing (TD) children. Cortical source modeling was applied to assess resting-state functional connectivity (rs-FC) in spatial attention networks (dorsal (DAN) and ventral attention networks (VAN)) implicated in visuospatial abilities. A machine-learning approach was applied to investigate whether group membership could be predicted from rs-FC maps and if these connectivity patterns were predictive of visuospatial performance. Graph theoretical measures were applied to nodes inside each network. EEG rs-FC maps in the gamma and beta band differentiated children with and without NVLD, with increased but more diffuse and less efficient functional connections bilaterally in the NVLD group. While rs-FC of the left DAN in the gamma range predicted visuospatial scores for TD children, in the NVLD group rs-FC of the right DAN in the delta range predicted impaired visuospatial performance, confirming that NVLD is a disorder with a predominant dysfunction in right hemisphere connectivity patterns.