Once again, we discover that sensory sensitivity, which is a well-documented aspect of ASD and Asperger experience, has had little “scientific” attention paid to the real physical phenomenon. This paper reveals evidence for the “experience” having a detectable origin in the brain-sensory system of ASD / Asperger individuals. We’re not “crazy” and / or “making up” this effect of environmental sensory “assault”.
Published in final edited form as: J Am Acad Child Adolesc Psychiatry. 2013 Nov; 52(11): 10.1016/j.jaac.2013.08.004.
Over-Reactive Brain Responses to Sensory Stimuli in Youth With Autism Spectrum Disorders RH: fMRI Response to Sensory Stimuli in ASD
Ms. Shulamite A. Green, M.A., University of California–Los Angeles (UCLA). (Complete author list – see original paper)
Sensory over-responsivity (SOR), defined as a negative response to or avoidance of sensory stimuli, is both highly prevalent and extremely impairing in youth with autism spectrum disorders (ASD), yet little is known about the neurological bases of SOR. This study aimed to examine the functional neural correlates of SOR by comparing brain responses to sensory stimuli in youth with and without ASD.
Twenty-five high-functioning youth with ASD, and 25 age- and IQ-equivalent typically developing (TD) youth were presented with mildly aversive auditory and visual stimuli during a functional magnetic resonance imaging (fMRI) scan. Parents provided ratings of children’s SOR and anxiety symptom severity.
Compared to TD participants, ASD participants displayed greater activation in primary sensory cortical areas as well as amygdala, hippocampus, and orbital-frontal cortex. In both groups, the level of activity in these areas was positively correlated with level of SOR severity as rated by parents, over and above behavioral ratings of anxiety.
This study demonstrates that youth with ASD show neural hyper-responsivity to sensory stimuli, and that behavioral symptoms of SOR may be related to both heightened responsivity in primary sensory regions as well as areas related to emotion processing, and regulation.
The paper is long and detailed: I need to carefully read for content that is especially relevant to “unraveling” the prejudice surrounding ASD / Asperger sensitivities, and the effects of exposure to modern artificial environments (chemicals, noise levels, air quality) on ALL humans, especially children. Will post…