Network centrality analysis of eye-gaze data in autism spectrum disorder

The final publication is available at Elsevier via https://doi.org/10.1016/j.compbiomed.2019.103332. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Individuals suffering from autism spectrum disorder (ASD) exhibit impaired social communication, the manifestations of which include abnormal eye contact and gaze. In this study, we first seek to characterize the spatial and temporal attributes of this atypical eye gaze. To achieve that goal, we analyze and compare eye-tracking data of ASD and typical development (TD) children. A fixation time analysis indicates that ASD children exhibit a distinct gaze pattern when looking at faces, spending significantly more time at the mouth and less at the eyes, compared with TD children. Another goal of this study is to identify an analytic approach that can better reveal differences between the face scanning patterns of ASD and TD children. Face scanning involves transitioning from one area of interest (AOI) to another and is not taken into account by the traditional fixation time analysis. Instead, we apply four network analysis approaches that measure the “importance” of a given AOI: degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality. Degree centrality and eignevector centrality yield statistically significant difference in the mouth and right eye, respectively, between the ASD and TD groups, whereas betweenness centrality reveals statistically significant between-group differences in four AOIs. Closeness centrality yields statistically meaningful differences in three AOIs, but those differences are negligible. Thus, our results suggest that betweenness centrality is the most effective network analysis approach in distinguishing the eye gaze patterns between ASD and TD children.This research was supported by the Canada 150 Research Chair program

Application of the eye tracking technology in medicine: a bibliometric analysis

Eye tracking provides a quantitative measure of eye movements during different activities. We report the results from a bibliometric analysis to investigate trends in eye tracking research applied to the study of different medical conditions. We conducted a search on the Web of Science Core Collection (WoS) database and analyzed the dataset of 2456 retrieved articles using VOSviewer and the Bibliometrix R package. The most represented area was psychiatry (503, 20.5%) followed by neuroscience (465, 18.9%) and psychology developmental (337, 13.7%). The annual scientific production growth was 11.14% and showed exponential growth with three main peaks in 2011, 2015 and 2017. Extensive collaboration networks were identified between the three countries with the highest scientific production, the USA (35.3%), the UK (9.5%) and Germany (7.3%). Based on term co-occurrence maps and analyses of sources of articles, we identified autism spectrum disorders as the most investigated condition and conducted specific analyses on 638 articles related to this topic which showed an annual scientific production growth of 16.52%. The majority of studies focused on autism used eye tracking to investigate gaze patterns with regards to stimuli related to social interaction. Our analysis highlights the widespread and increasing use of eye tracking in the study of different neurological and psychiatric conditions

Mecanismos de comprensión lectora en el trastorno del espectro autista: procesos metacognitivos y función ejecutiva

This thesis aims to increase the understanding of the metacognitive processes and executive function underlying reading comprehension deficits in autism spectrum disorder (ASD). This aim was achieved using behavioural assessments and eye-tracker technology. Although the problems in reading comprehension in ASD have been broadly investigated, the reasons why they occur and the processes that are involved are still poorly understood. Chapter 1 of the thesis provides an overview of the literature related to the cognitive components that influence reading comprehension in typically developing and individuals with ASD. The next chapters present three experiments respectively exploring different components that may influence reading comprehension in ASD: inference generation (Chapter 2), reading monitoring (Chapter 3) and adaptation to reading goals (Chapter 4). In order to observe if differences in reading behaviour where present in absence of cognitive and language impairment, all the studies include children and adolescents with ASD carefully matched with individuals without ASD on chronological age, receptive oral language, nonverbal intelligence and reading speed. Chapter 2 confirmed the hypothesis that individuals with ASD and a high level of oral language show subtle differences in reading strategies compared to the control group. In order to see if differences in reading behavior could be due to top-down modulation strategies, we explored the adaptation to different instructions. Chapter 3 shows limited evidence that individuals with ASD can positively affect their ability to detect errors in reading in response to specific instructions. However, they still seemed to have a different reading pattern compared to controls showing to be less responsive to the type of error. Finally, since the error-detection task is an artificial task, with the next experiment, we further explored top-down modulation strategies using a more ecological task. Chapter 4 reveals that individuals with ASD change their reading behavior according to the reading goals differently from controls, with less adaptation of their deep-level processing strategies when necessary. Planning, measured by the Tower of Hanoi, was the only executive component that predicted the strategy change between specific reading conditions. This pattern of behavior illustrates that reading comprehension problems may be partially explained by difficulties in adjusting the reading behavior according to the task and in planning. Taken together these studies confirm the already suspected differences in the online processing of reading materials for individuals with ASD, above and beyond oral language deficits, and reveal novel cognitive sources such as metacognition and executive function that may impact reading comprehension in ASD.Esta tesis tiene como objetivo explorar el papel de los procesos metacognitivos y de la función ejecutiva en la comprensión lectora en personas con trastorno del espectro del autismo (TEA). Para ello se han desarrollado experimentos conductuales y con eye-tracker. Los problemas de comprensión lectora en TEA han sido ampliamente investigados; sin embargo, las razones por la que se producen y los procesos que están involucrados en ellos todavía han sido poco explorados. El Capítulo 1 describe los componentes cognitivos que influyen en la comprensión lectora en personas de desarrollo típico y con TEA. Los capítulos siguientes exploran tres componentes que pueden influenciar la comprensión lectora: la generación de inferencias (Capitulo 2), la monitorización de la lectura (Capitulo 3) y la adaptación a los objetivos de lectura (Capitulo 4). Para observar si las diferencias en el comportamiento lector están presentes en ausencia de discapacidades cognitivas o lingüísticas, todos los estudios incluyen niños y adolescentes con TEA cuidadosamente emparejados con un grupo de individuos sin TEA en edad cronológica, lenguaje oral receptivo, inteligencia no verbal y velocidad lectora. El Capítulo 2 demuestra que los individuos con TEA, a pesar de tener un nivel equivalente de comprensión inferencial, muestran sutiles diferencias en las estrategias lectoras en comparación con el grupo de control. Con el fin de ver si las diferencias en el comportamiento de lectura podrían ser debidas a las estrategias de modulación top-down, hemos explorado la adaptación a diferentes instrucciones. El capítulo 3 muestra pruebas limitadas de que las personas con TEA pueden modificar positivamente su capacidad de detectar errores en la lectura en respuesta a instrucciones específicas. Sin embargo, todavía parecen tener un patrón de lectura diferente en comparación con los controles. Finalmente, dado que la tarea de detección de errores es una tarea artificial, con el siguiente experimento, exploramos más las estrategias de modulación top-down usando una tarea más ecológica. El Capítulo 4 revela que las personas con TEA cambian menos su comportamiento lector de acuerdo con los objetivos de lectura, mostrando una menor tendencia a adaptar sus estrategias profundas de procesamiento a los requisitos de la tarea. La planificación, medida con la Torre de Hanoi, fue el único componente ejecutivo que predijo el cambio de estrategia entre condiciones específicas de lectura. Este patrón de comportamiento ilustra que los problemas de comprensión lectora pueden explicarse en parte por las dificultades para ajustar el comportamiento de lectura a la tarea y en la planificación. En conjunto, estos estudios confirman las ya sospechadas diferencias en el procesamiento on-line de materiales de comprensión lectura para individuos con TEA en comparación con un grupo de control, y también revelan nuevos procesos cognitivos, tales como la metacognición y la función ejecutiva, que podrían impactar en su comprensión lectora.Premio Extraordinario de Doctorado U

The benefit of directly comparing autism and schizophrenia for revealing mechanisms of social cognitive impairment

Autism and schizophrenia share a history of diagnostic conflation that was not definitively resolved until the publication of the DSM-III in 1980. Though now recognized as heterogeneous disorders with distinct developmental trajectories and dissociative features, much of the early nosological confusion stemmed from apparent overlap in certain areas of social dysfunction. In more recent years, separate but substantial literatures have accumulated for autism and schizophrenia demonstrating that abnormalities in social cognition directly contribute to the characteristic social deficits of both disorders. The current paper argues that direct comparison of social cognitive impairment can highlight shared and divergent mechanisms underlying pathways to social dysfunction, a process that can provide significant clinical benefit by informing the development of tailored treatment efforts. Thus, while the history of diagnostic conflation between autism and schizophrenia may have originated in similarities in social dysfunction, the goal of direct comparisons is not to conflate them once again but rather to reveal distinctions that illuminate disorder-specific mechanisms and pathways that contribute to social cognitive impairment

Rapid Systematic Review of Occupational Therapy-Adaptable Interventions to Improve Social Engagement in Children and Adolescents with Autism Spectrum Disorder

Indiana University Purdue University IndianapolisIn this rapid systematic review, we describe how evidence-based interventions aiming to improve social engagement in children and adolescents with Autism Spectrum Disorder (ASD) can be potentially adapted to be included within the scope of occupational therapy. Children and adolescents with ASD often experience difficulty with social engagement, impacting overall social participation and other aspects of daily life. It is important to address this issue within this population to ensure engagement in the occupation of social participation, which is vital to optimal health and well-being. We discovered several themes including communication, joint attention, peer engagement, social skills, and play as outcomes addressed within the interventions included in this review. There is limited research available regarding social engagement interventions for children and adolescents with ASD directly including an occupational therapist within the intervention. This review demonstrates that there is a large variety of social engagement interventions that could be implemented by occupational therapists; however, therapists must be mindful of choosing an intervention that is specific to the client's condition. There is strong evidence to suggest that interventions targeting social engagement in children and adolescents with ASD result in increased social abilities. Further research should be conducted assessing the implementation of these interventions by occupational therapists to ensure generalizability.Occupational Therap

Developmental and sex modulated neurological alterations in autism spectrum disorder

Autism Spectrum Disorder (ASD) was first described in 1943 by Dr. Leo Kranner in a case study published in The Nervous Child. It is a neurodevelopment disorder, with a range of clinical symptoms. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), used by clinicians to diagnose mental disorders, a child needs to have persistent social deficits, language impairments, and repetitive behaviors, that cannot be explained by neurological damage or intellectual disability. It is known that children diagnosed with ASD are often are developmentally delayed therefore alterations in the typical developmental trajectory should be a major factor in consideration when studying ASD. As of 2016, 1 in 68 children in the USA is diagnosed with ASD, of those diagnosed young males are four times more likely to be diagnosed than their female peers. Although genetic and behavioral theories exist to explain these differences, the cause for the disparity is still unknown. This Dissertation presents a unique opportunity to understand the intersection of altered neurodevelopment and the alarming sex disparities in patients with ASD from a neuroimaging perspective. The hypothesis is that there exist differences due to development and sex in with ASD. Access to ABIDE (Autism Brain Imaging Data Exchange), a open source large scale data sharing consortium of functional and anatomical MR data. Analyzing MR data for alterations due to ASD, developmental trajectory, and sex as well as the intersection of these factors. Theses modulations are observed in three Project Aims that employ various analytical approaches: (1) Structural Morphology, (2) Resting-state Functional Connectivity, and (3) Graph Theory. The major findings lie at the interaction of these three factors; developmental stage-by-diagnosis-by-sex. Structural Morphological Analyses of anatomical data show differences in cortical thickness, on the left rostral middle frontal gyrus and surface area in along the sensory motor strip, of the left paracentral gyrus and right precentral gyrus. Resting-state Functional Connectivity analyzed in multiple data driven approaches, and altered resting state connectivity patterns between the left frontal parietal network and the left parahippcampal gyrus are reported. The regions found in the Morphological Analyses are used as seeds for a priori connectivity analysis, connectivity between the left rostral middle frontal cortex and bilateral superior temporal gyrus as well as the right precentral gyrus and right middle frontal gyrus and left inferior frontal gyrus are described. Finally using Graph Theory analysis, which quantifies a whole brain connectivity matrix to calculate metrics such as path length, cluster coefficient, local efficiency, and betweeness centrality all of which are altered by the interaction of all three factors. The last investigation is an attempt to correlate the behavioral assessments, conducted by clinicians with theses neuroimaging findings to determine if there exist a relationship between them. Significant interaction effects of sex and development on ASD diagnosis are observed. The goal of the Study is to provide more information on the disorder that is by nature highly heterogeneous in symptomatology. Studying these interactions, may be key to better understand a disorder that was introduced into the medical literature 75 years ago

Bottom-up vs. top-down connectivity imbalance in individuals with high-autistic traits: An electroencephalographic study

Brain connectivity is often altered in autism spectrum disorder (ASD). However, there is little consensus on the nature of these alterations, with studies pointing to either increased or decreased connectivity strength across the broad autism spectrum. An important confound in the interpretation of these contradictory results is the lack of information about the directionality of the tested connections. Here, we aimed at disambiguating these confounds by measuring differences in directed connectivity using EEG resting-state recordings in individuals with low and high autistic traits. Brain connectivity was estimated using temporal Granger Causality applied to cortical signals reconstructed from EEG. Between-group differences were summarized using centrality indices taken from graph theory (in degree, out degree, authority, and hubness). Results demonstrate that individuals with higher autistic traits exhibited a significant increase in authority and in degree in frontal regions involved in high-level mechanisms (emotional regulation, decision-making, and social cognition), suggesting that anterior areas mostly receive information from more posterior areas. Moreover, the same individuals exhibited a significant increase in the hubness and out degree over occipital regions (especially the left and right pericalcarine regions, where the primary visual cortex is located), suggesting that these areas mostly send information to more anterior regions. Hubness and authority appeared to be more sensitive indices than the in degree and out degree. The observed brain connectivity differences suggest that, in individual with higher autistic traits, bottom-up signaling overcomes top-down channeled flow. This imbalance may contribute to some behavioral alterations observed in ASD

Visual Scanning of Dynamic Affective Stimuli in Autism Spectrum Disorders

The accurate integration of audio-visual emotion cues is critical for social interactions and requires efficient processing of facial cues. Gaze behavior of typically developing (TD) individuals and individuals with autism spectrum disorders (ASD) was measured via eye-tracking during the perception of dynamic audio-visual emotion (DAVE) stimuli. This study provides information about the regions of the face sampled during an emotion perception task that is relatively more complex than those used in previous studies, providing both bimodal (auditory and visual) and dynamic (biological motion) cues. Results indicated that the ASD group was less accurate at emotion detection and demonstrated less of a visual-affective bias than TD individuals. Both groups displayed similar fixation patterns across regions during the perception of congruent audio-visual stimuli. However, between-group analyses revealed that fixation patterns differed significantly by facial regions during the perception of both congruent and incongruent movies together. In addition, fixation duration to critical regions (i.e., face, core, eyes) was negatively correlated with measures of ASD symptomatology and social impairment. Findings suggest weaknesses in the early integration of audio-visual information, automatic perception of emotion, and efficient detection of affective conflict in individuals with ASD. Implications for future research and social skills intervention programs are discussed

Beyond the cortico-centric models of cognition: the role of subcortical functioning in neurodevelopmental disorders

The main aim of the present opinion article is to discuss and argue how the classic cortico-centricmodel of neurodevelopmental disorders is not exhaustive of the possible explanation of thesedisorders. The alternative proposal presented here is to include the cortico-subcortical networkmodel to explain them

Central vestibular networking for sensorimotor control, cognition, and emotion

Purpose of reviewThe aim of this study was to illuminate the extent of the bilateral central vestibular network from brainstem and cerebellum to subcortical and cortical areas and its interrelation to higher cortical functions such as spatial cognition and anxiety.Recent findingsThe conventional view that the main function of the vestibular system is the perception of self-motion and body orientation in space and the sensorimotor control of gaze and posture had to be developed further by a hierarchical organisation with bottom-up and top-down interconnections. Even the vestibulo-ocular and vestibulo-spinal reflexes are modified by perceptual cortical processes, assigned to higher vestibulo-cortical functions. A first comparative fMRI meta-analysis of vestibular stimulation and fear-conditioning studies in healthy participants disclosed widely distributed clusters of concordance, including the prefrontal cortex, anterior insula, temporal and inferior parietal lobe, thalamus, brainstem and cerebellum. In contrast, the cortical vestibular core region around the posterior insula was activated during vestibular stimulation but deactivated during fear conditioning. In recent years, there has been increasing evidence from studies in animals and humans that the central vestibular system has numerous connections related to spatial sensorimotor performance, memory, and emotion. The clinical implication of the complex interaction within various networks makes it difficult to assign some higher multisensory disorders to one particular modality, for example in spatial hemineglect or room-tilt illusion.SummaryOur understanding of higher cortical vestibular functions is still in its infancy. Different brain imaging techniques in animals and humans are one of the most promising methodological approaches for further structural and functional decoding of the vestibular and other intimately interconnected networks. The multisensory networking including cognition and emotion determines human behaviour in space