A Mechanistic Understanding of Atypical Visual Processing in Autism Spectrum Disorder PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A Mechanistic Understanding of Atypical Visual Processing in Autism Spectrum Disorder PDF full book. Access full book title A Mechanistic Understanding of Atypical Visual Processing in Autism Spectrum Disorder by Woon Ju Park. Download full books in PDF and EPUB format.
Author: Woon Ju Park Publisher: ISBN: Category : Autism spectrum disorders Languages : en Pages : 134
Book Description
"A growing number of studies suggest atypical visual processing in autism spectrum disorder (ASD). Given that human behavior heavily relies on visual information, impairments in visual processing may have cascading effects on many other brain functions. Recent proposals in ASD, both domain-specific and -general, hypothesize different mechanisms that may impact visual abilities in this population. However, empirical support for such accounts has been lacking, and it is unclear whether and how these mechanisms can influence visual perception in ASD. The series of studies in this dissertation examine atypical visual processing mechanisms in ASD under three frameworks: larger receptive field size, elevated internal noise, and impaired prediction abilities. We examine each of these hypotheses in children and adolescents with ASD, using a combination of psychophysics, computational modeling, and eye-tracking. In Chapter 2, we tested the integrity of receptive field size using a visual motion discrimination task. The results showed that individuals with ASD have impaired motion sensitivity at smaller stimulus size, which was best explained by the larger receptive field size account. In Chapter 3, we investigated whether internal noise is elevated in ASD, and found evidence that supports this account. Importantly, we found that higher internal noise was associated with more severe behavioral symptoms of ASD. Lastly, in Chapter 4, we examined the prediction abilities in ASD in the context of visual motion extrapolation. The results demonstrate impaired motion prediction in ASD, which was also accompanied by their atypical eye-movement patterns during the task. Taken together, these studies reveal deficits in visual processing in ASD across a wide range of processing stages. The findings not only provide empirical support for existing proposals of ASD, but also shed lights on the specific mechanisms associated with atypical visual abilities in this population."--Pages viii-ix.
Author: Woon Ju Park Publisher: ISBN: Category : Autism spectrum disorders Languages : en Pages : 134
Book Description
"A growing number of studies suggest atypical visual processing in autism spectrum disorder (ASD). Given that human behavior heavily relies on visual information, impairments in visual processing may have cascading effects on many other brain functions. Recent proposals in ASD, both domain-specific and -general, hypothesize different mechanisms that may impact visual abilities in this population. However, empirical support for such accounts has been lacking, and it is unclear whether and how these mechanisms can influence visual perception in ASD. The series of studies in this dissertation examine atypical visual processing mechanisms in ASD under three frameworks: larger receptive field size, elevated internal noise, and impaired prediction abilities. We examine each of these hypotheses in children and adolescents with ASD, using a combination of psychophysics, computational modeling, and eye-tracking. In Chapter 2, we tested the integrity of receptive field size using a visual motion discrimination task. The results showed that individuals with ASD have impaired motion sensitivity at smaller stimulus size, which was best explained by the larger receptive field size account. In Chapter 3, we investigated whether internal noise is elevated in ASD, and found evidence that supports this account. Importantly, we found that higher internal noise was associated with more severe behavioral symptoms of ASD. Lastly, in Chapter 4, we examined the prediction abilities in ASD in the context of visual motion extrapolation. The results demonstrate impaired motion prediction in ASD, which was also accompanied by their atypical eye-movement patterns during the task. Taken together, these studies reveal deficits in visual processing in ASD across a wide range of processing stages. The findings not only provide empirical support for existing proposals of ASD, but also shed lights on the specific mechanisms associated with atypical visual abilities in this population."--Pages viii-ix.
Author: Jacalyn Guy Publisher: ISBN: Category : Languages : en Pages :
Book Description
"This thesis examines the development of visual perception in children and adolescents with Autism Spectrum Disorder (ASD), with a specific focus on local and global processes. The current perceptual profile in ASD is characterized by a unique set of strengths and weaknesses in visual information processing at lower and higher-levels. These are generally described by strengths in processing lower-level, detailed information of a non-social nature and weaknesses in processing higher-level, global information of a social nature. Two issues limit the current understanding of this profile; a developmental perspective is lacking and associations across levels of lower- and higher-levels of processing are unclear. The studies presented here have charted, for the first time, cross-sectional developmental trajectories of lower- and higher-level visual perception for both social and non-social information. These studies were motivated by empirically driven questions and based on findings in adults with ASD, which have suggested that enhanced perception of detailed information occurs at lower-levels of processing (Kéïta, Guy, Berthiaume, Mottron, & Bertone, 2014) and may impact upon social perception at higher-levels (Morin et al., 2015). Participants with ASD and typically-developing (TD) comparisons aged 6 to 16 years completed behavioural tasks assessing lower- and higher-level, social and non-social visual perception, particularly in terms of local and global processing. These included spatial frequency, visuo-spatial (i.e., Navon task), and facial identity discrimination tasks. Results revealed that children and adolescents with ASD process local and global aspects of non-social information somewhat differently than TD comparisons at lower- and higher-levels (i.e., spatial frequency and Navon tasks). The strongest result was that local information interfered with the processing of global information in participants with ASD, specifically for higher-level, non-social information (i.e., Navon task). Moreover, the trajectories of local and global performances across levels of processing and type of information collectively indicated that adolescence is likely an important period of transition in visual perception in ASD. This was especially evident for lower-level, non-social and higher-level, social information (i.e., spatial frequency and face identity discrimination tasks, respectively).Associations across task performance provide preliminary evidence that enhanced processing of detailed information at lower-levels of processing influences non-social perception at higher-levels. Further to this, associations within higher-levels of processing suggest that the influence of local information may similarly interfere or distract with how social and non-social information is processed. These findings reveal complex relationships between local and global processes, suggesting that alterations in the "building blocks" of perception may relate to atypical, higher-order cognitive and social processes in ASD. These findings advance the notion that the atypical processing of sensory information may explain, in part, some of the social difficulties fundamental to ASD. They further highlight the importance of cross-level and cross-task comparisons of perceptual processes within a developmental framework, and support calls for a comprehensive understanding of how adult outcomes are achieved. " --
Author: Katarzyna Chawarska Publisher: Guilford Publications ISBN: 1462543251 Category : Psychology Languages : en Pages : 360
Book Description
Synthesizing an explosion of recent research, this book presents dramatic advances in understanding and treating autism spectrum disorder (ASD) in very young children. Leading authorities describe the innovative tools and methods that are enabling clinicians to more effectively identify 0- to 5-year-olds with the disorder and those at risk for related problems. Chapters discuss the early core symptoms and co-occurring characteristics of ASD, the best diagnostic instruments, and lessons learned from large-scale screening and surveillance, including sibling studies. The book reviews evidence-based interventions and explores practical issues in treatment of young children and their families.
Author: Benjamin Gesundheit Publisher: Frontiers Media SA ISBN: 2889451127 Category : Languages : en Pages : 180
Book Description
Autism Spectrum Disorder (ASD) is currently diagnosed based on a series of behavioral tests. The challenge for researchers is to try to uncover the biological basis for these typical behaviors in order to improve diagnosis and identify potential targets for treatment. A multidisciplinary approach is necessary in order to move forward. This includes analysis of the current animal models for ASD and their suitability, reviewing immunological, immunogenetic and epigenetic research, reassessing clinical diagnostic tools, and surveying radiological, pathological, and serological records for clues. This volume includes research from some of the leading researchers on ASD. We are hopeful that it will stimulate further dialogue and research in this challenging field.
Author: Joseph I. Tracy Publisher: Oxford University Press, USA ISBN: 0199965242 Category : Medical Languages : en Pages : 433
Book Description
This volume makes clear that the cognitive and behavioural symptoms of neurologic disorders and syndromes are dynamic and changing. Each chapter describes the neuroplastic processes at work in a particular condition, giving rise to these ongoing cognitive changes.
Author: Deborah Anne Kathryn Martin Publisher: ISBN: Category : Languages : en Pages : 87
Book Description
Individuals within the autism spectrum disorder (ASD) tend to show strong local bias when analysing incoming information. Some postulate this could be due to a more detail-oriented cognitive style, which embraces an initial local processing of a scene when viewing events (Mottron & Burack, 2001). It has also been shown that constraining verbs, which can be mapped onto a limited number of objects in a scene, can lead to an anticipation of upcoming nouns in a sentence, as shown by anticipatory eye movements to the target object of the sentence (e.g., Altmann & Kamide, 1999). The goal of the present study was to investigate whether or not linguistic-and-visual synchronized dynamic events could lead to enhanced processing in children with ASD. Using the visual world paradigm (VWP), children with and without ASD watched dynamic scenes (with and without goal-directed action) that were matched with related sentences. Sentences contained either a constraining (causative) or non-constraining (perception/psychological) verb. It was hypothesized that those with ASD, but not neuro-typically developing (NT) children, would show anticipatory eye movements to the (target) object in the scene based on the constraining nature of causative as opposed to perception/psychological verbs. Secondly, we postulated that those scenes with goal directed action would disrupt the ability of children with ASD to find the target object, due to their poor understanding of agent intent. Results showed that while those with ASD could not anticipate upcoming sentential information, they were faster than NT children at locating the target object in the scene when presented causative sentences. In addition, agent goal-directed action did not distract the attention of those with ASD when trying to locate the target object. We suggest that these findings could provide evidence of a detail-oriented cognitive style in ASD when viewing scenes and listening to sentences concomitantly.
Author: K. Sathian Publisher: Academic Press ISBN: 0128125640 Category : Psychology Languages : en Pages : 490
Book Description
Multisensory Perception: From Laboratory to Clinic surveys the current state of knowledge on multisensory processes, synthesizing information from diverse streams of research and defining hypotheses and questions to direct future work. Reflecting the nature of the field, the book is interdisciplinary, comprising the findings and views of writers with diverse backgrounds and varied methods, including psychophysical, neuroanatomical, neurophysiological and neuroimaging approaches. Sections cover basic principles, specific interactions between the senses, the topic of crossmodal correspondences between particular sensory attributes, the related topic of synesthesia, and the clinic. - Offers a comprehensive, up-to-date overview of the current state of knowledge on multisensory processes - Coverage includes basic principles, specific interactions between the senses, crossmodal correspondences and the clinical aspects of multisensory processes - Includes psychophysical, neuroanatomical, neurophysiological and neuroimaging approaches
Author: Woon Ju Park
Author: Woon Ju Park
Author: 
Author: Myriam Vandenbroucke
Author: Jacalyn Guy
Author: Francesca Happé
Author: Katarzyna Chawarska
Author: Benjamin Gesundheit
Author: Joseph I. Tracy
Author: Deborah Anne Kathryn Martin
Author: K. Sathian