Atypical frontal connectivity associated with cognitive deficits in children with ASD : evidence from fNIRS studies

Abstract

This thesis aims to fill a research gap in the neurocognitive understanding of Autism Spectrum Disorder (ASD), a neurodevelopmental disorder marked by a spectrum of social, communicative, and behavioral challenges. Although ASD's behavioral aspects have been extensively studied, there remains a substantial void in comprehending the precise neural and executive functioning deficits that form the foundation of these challenges. To address this, the thesis examines the interactions between executive dysfunction, abnormal prefrontal connectivity, and information processing challenges in ASD, utilizing functional near-infrared spectroscopy (fNIRS) alongside assessments of executive function. Initial findings reveal significant difficulties in tasks demanding cognitive flexibility, specifically tied to hypoconnectivity in the prefrontal cortex, particularly the bilateral lateral PFC. This condition underlies the compromised efficiency in information processing observed in individuals with ASD. The work further delves into the impact of working memory load on prefrontal connectivity in children with ASD, unveiling distinct patterns of functional connectivity under varying memory demands. These insights shed light on the cognitive challenges linked to working memory and their broader implications for cognitive functioning within this population. Finally, the thesis delves into the challenges individuals with ASD encounter in reading comprehension, underscoring that these difficulties may entrenched in executive dysfunctions. These challenges are closely linked to slower information processing speeds and diminished functional connectivity in the prefrontal cortex during complex cognitive tasks, indicating a significant struggle among individuals with ASD in integrating complex information. Although the focus of this research is on high-functioning individuals with ASD, it highlights the critical need for future studies to encompass a broader spectrum of ASD populations. The implications of these findings stretch beyond mere theoretical insights, paving the way for interventions and support mechanisms tailored to the nuanced needs of individuals with ASD.