Disrupted cortical connectivity theory as an explanatory model for autism spectrum disorders

Recent findings of neurological functioning in autism spectrum disorder (ASD) point to altered brain connectivity as a feature of its pathophysiology. The cortical underconnectivity theory of ASD (Just et al., 2004) provides an integrated framew for addressing these new findings. This theory suggests that weaker functional connections among brain areas in those with A hamper their ability to accomplish complex cognitive and social tasks successfully. We will discuss this theory, but will modify term underconnectivity to 'disrupted cortical connectivity' to capture patterns of both under- and over-connectivity in the brain this paper, we will review the existing literature on ASD to marshal supporting evidence for hypotheses formulated on the disrupted cortical connectivity theory. These hypotheses are: I) underconnectivity in ASD is manifested mainly in long-distance cortica well as subcortical connections rather than in short-distance cortical connections; 2) underconnectivity in ASD is manifested o in complex cognitive and social functions and not in low-level sensory and perceptual tasks; 3) functional underconnectivity ASD may be the result of underlying anatomical abnormalities, such as problems in the integrity of white matter; 4) the A brain adapts to underconnectivity through compensatory strategies such as overconnectivity mainly in frontal and in posterior bi areas. This may be manifested as deficits in tasks that require frontal parietal integration. While overconnectivity can be tested examining the cortical minicolumn organization, long-distance underconnectivity can be tested by cognitively demanding tas and 5) functional underconnectivity in brain areas in ASD will be seen not only during complex tasks but also during task-I resting states. We will also discuss some empirical predictions that can be tested in future studies, such as: I) how disrupted connectivity relates to cognitive impairments in skills such as Theory-of-Mind, cognitive flexibility, and information processing and 2) how connection abnormalities relate to, and may determine, behavioral symptoms hallmarked by the triad of Impairment. in ASD. Furthermore, we will relate the disrupted cortical connectivity model to existing cognitive and neural models of ASD. Published by Elsevier B. V.