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Arousal refers to the physiological state of readiness or general state of excitation of one’s nervous system. Arousal states lie on a continuum from low to high, and the ability to maintain optimal arousal levels is often required for adaptive interaction with one’s environment. Hypo-arousal refers to an arousal state that lies of the low end of this continuum. Behaviorally, hypo-arousal may be observed as under-responsiveness to stimuli and one’s environment, for example, as lethargy, inattention, apathy, or boredom.

Theories of hypo-arousal in autism originated in the 1960s, linked directly to the idea of autism-specific deficits in the arousal system per se, specifically implicating the reticular activating system (Rimland, 1964). Although general arousal levels have since been found to be normal in persons with autism, there is empirical support for under-arousal in response to specific sensory stimuli in many persons with autism. For example,...

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References and Readings

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Correspondence to Sandra Hodgetts .

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© 2013 Springer Science+Business Media New York

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Hodgetts, S. (2013). Hypo-arousal. In: Volkmar, F.R. (eds) Encyclopedia of Autism Spectrum Disorders. Springer, New York, NY.

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