Neural noise in Autism Spectrum Conditions (ASC)

Increased neural noise is proposed to be a potential endophenotype of Autism Spectrum Conditions (ASC), capturing disrupted neural synchrony dynamics inherent to the condition. Nevertheless, the neural noise hypothesis of ASC has not been previously examined systematically. Using Electroencephalography (EEG), the present thesis investigates neural noise by measuring the degree of phase angle alignment of neural oscillations between experimental trials through the Inter-trial Phase Coherence (ITPC) metric and the steepness of 1/f noise slope of Power Spectral Density (PSD), a variable quantifying broadband changes in power spectra as a function of temporal frequency in a visual task-based and a resting state condition. The present thesis comprises of four studies: a) an investigation of neural noise in clinical samples of adults with ASC and ADHD b) the presentation of a new accessible method of studying brain activity of autistic individuals at home, using mobile EEG technology, c) a study of neural noise in a large sample of children with ASC (n=67) and d) an investigation of the relationship between neural noise and behavioural symptoms associated with the ASC phenotype. In the present thesis it was established that increased neural variability in the form of low ITPC occurs only in a group of children with ASC. Although levels of ITPC differed significantly between children with and without ASC at a group level, low ITPC could not differentiate participants with ASC from participants without ASC with adequately high accuracy to be considered a biomarker of ASC, as proposed in the literature (David et al., 2016). In addition, it was demonstrated that ITPC, as measured in response to visual stimulation, is not linked to primary phenotypic expressions of ASC but is associated with anomalous visual experiences and visual distortions, a group of visuoperceptual symptoms shown to manifest with varying prevalence in individuals with ASC and other people in the general population. Finally, it was established that 1/f noise power spectral dynamics, measured during processing of simple visual stimuli and during rest, were intact in the ASC and ADHD samples tested, providing evidence against the pathological undercoupling hypothesis proposed by Voytek & Knight (2015)

Anxiety, concerns and COVID-19: Cross-country perspectives from families and individuals with neurodevelopmental conditions

BackgroundThe COVID-19 pandemic had a major impact on the mental health and well-being of children with neurodevelopmental conditions (NDCs) and of their families worldwide. However, there is insufficient evidence to understand how different factors (e.g., individual, family, country, children) have impacted on anxiety levels of families and their children with NDCs developed over time.MethodsWe used data from a global survey assessing the experience of 8043 families and their children with NDCs (mean of age (m) = 13.18 years, 37% female) and their typically developing siblings (m = 12.9 years, 45% female) in combination with data from the European Centre for Disease Prevention and Control, the University of Oxford, and the Central Intelligence Agency (CIA) World Factbook, to create a multilevel data set. Using stepwise multilevel modelling, we generated child-, family- and country-related factors that may have contributed to the anxiety levels of children with NDCs, their siblings if they had any, and their parents. All data were reported by parents.ResultsOur results suggest that parental anxiety was best explained by family-related factors such as concerns about COVID-19 and illness. Children’s anxiety was best explained by child-related factors such as children’s concerns about loss of routine, family conflict, and safety in general, as well as concerns about COVID-19. In addition, anxiety levels were linked to the presence of pre-existing anxiety conditions for both children with NDCs and their parents.ConclusionsThe present study shows that across the globe there was a raise in anxiety levels for both parents and their children with NDCs because of COVID-19 and that country-level factors had little or no impact on explaining differences in this increase, once family and child factors were considered. Our findings also highlight that certain groups of children with NDCs were at higher risk for anxiety than others and had specific concerns. Together, these results show that anxiety of families and their children with NDCs during the COVID-19 pandemic were predicted by very specific concerns and worries which inform the development of future toolkits and policy. Future studies should investigate how country factors can play a protective role during future crises