Recent advances in understanding the neural bases of autism spectrum disorder

Abstract

Purpose of review This paper reviews current work investigating the neural bases of autism spectrum disorder (ASD) within the discipline of electrophysiological brain research. The manuscript focuses primarily on advances in understanding related to social information processing and interconnectivity among brain systems in ASD. Recent findings Recent research indicates anomalous function of social brain regions in ASD and highlights the specificity of processing problems to these systems. Atypical activity in this circuitry may reflect genetic susceptibility for ASD, with increased activity in compensatory areas marking the distinction between developing or not developing the disorder. Advances in understanding connectivity in ASD are highlighted by novel work providing initial evidence of atypical interconnectivity in infancy. Summary Emerging understanding of neural dysfunction in ASD indicates consistent but heterogeneous dysfunction across brain systems in ASD. Key objectives for the immediate future include: the use of multimethod approaches that encompass temporal and spatial imaging; behavioral phenotyping carried out in developmental context to reveal subgroups defined uniquely by trajectories; and individual-specific profiles of behavioral performance and brain function.

Anatomic and Functional Connectivity Relationship in Autistic Children During Three Different Experimental Conditions

“…ASD has been defined as a neurodevelopmental disorder with associated deficits in executive function, language, emotional, and social function Belmonte et al, 2004a;Belmonte et al, 2004b;Bellando and Fussell, 2011;Boisvert et al, 2010;Daniels et al, 2011;Horovitz et al, 2011a;Horovitz et al, 2011b;Mattila et al, 2010;McPartland et al, 2011;Rapin 4 novel DW-MRI and Graph Theory methodology was introduced with the principal purpose of summarizing anatomical connections patterns between brain gray matter areas (Adler et al, 2010;Iturria-Medina et al, 2007;Iturria-Medina et al, 2008;Li et al, 2014a).…”

Latest findings in autism research: how do they support the importance of early diagnosis and immediate intervention?

“…Indeed, whereas Courchesne et al [85] reported reduced cerebral volume from the age of 7 years, Ecker and colleagues observed a mixture of increased and decreased gray matter volumes in a different sample of adults with ASD [87]. Similarly, meta-analyses summarising the observations of large number of studies indeed do not point to a con sistent and robust pattern of anatomical changes associated with autism [23,88,89]. As suggested by Lenroot and Yeung [24], future studies will have to include large sample size and subdivide individuals with autism into subgroups to examine whether specific anatomical differences can be observed in more homogeneous samples to provide a more coherent account for changes in the structure of the brain in autism.…”

The molecular basis of cognitive deficits in pervasive developmental disorders: Table 1.

“…This "triad of deficits" can be thought of as an overall "problem" in social cognition. The severity of the condition may range from inability to process simple cues such as gaze fixation to complex operations such as biologic motion sensing, triadic attention sharing, and behavioral requesting (McPartland et al 2011). The intellectual quotient (IQ) of individuals with PDD varies across a broad range, but is a strong predictor of the expression of the disorder, the level of cognitive abilities observed, and treatment outcomes (Baron-Cohen 2004).…”

“…A plethora of imaging studies conducted with autistic and nonautistic children in a variety of contexts have helped identify several key difficulties with higher order cognitive processing. First, it is believed that deficits occur due to altered development of key brain areas involved in the processing of social and operational information (see McPartland et al 2011 …”