Abnormal Sensory Responsiveness
Abnormal Sensory Responsiveness
Studies suggest that many children with ASD show difficulty with sensory modulation. Further, some parents report that abnormal sensory responsiveness in their children affect their children's social, cognitive, and sensorimotor development. Moderate to strong correlations between SRS and each of the six sections of the sensory profile test have been seen. This indicates a moderate to strong relationship between children's social impairment and atypical sensory responsiveness. Multisensory, oral sensory/olfactory, and touch appear to be the areas of sensory responsiveness that are most predictive of social abilities in children.
Types of behaviors
Auditory stimuli
Both hyper-responsiveness to specific noises and under-responsiveness to noise has been reported in those with autism. Better than normal pitch has also been seen, and one study reported that there were disturbances in cognitive evoked potentials where subjects must give a specific response to a target stimulus and ignore another unusual stimulus in those with ASD. These disturbances suggested that there were alterations in attentional processing and auditory processing and identification. Some researchers suggest that atypical responses to auditory stimuli may lead some with ASD to behavior inappropriately.
Visual Stimuli
Abnormal response to visual stimuli can manifest itself through behaviors where children prefer to be in the dark, avoid bright lights, or looking intensely at objects or people. Visual motion perception deficits have been reported in those with autism.
Vestibular Stimuli
Behaviors include anxiety when feet leave the ground, or an avoidance of playground equipment or moving toys, an inability to stay still or rocking unconsciously.
Tactile Stimuli
Distress during grooming, abnormal reactions to touch, irritation at wearing shoes or socks or an avoidance of going barefoot, or having difficulty standing in line close to others may be a result of hyper-responsiveness to tactile stimuli. Hypo-responsiveness may manifest itself through decreased awareness of pain and temperature, not seeming to notice when one's face or hands are messy, or displaying an unusual need to touch certain toys, surfaces, or textures. One study suggested that children with hyper-responsiveness to tactile stimuli were more likely to display other autistic behaviors.1
Multisensory Stimuli
Children may have hyper or under responsiveness to task which involve multisensory responsiveness. Children may have difficulty paying attention, seem oblivious in an active environment, or have narrow food preferences. Multiple regression analysis showed that multisensory processing significantly predicted the degree of autistic pathology in children.
Citations
1. Hilton CL et. al. Sensory responsiveness as a predictor of social severity in children with high functioning autism spectrum disorders.J Autism Dev Disord. 2010 Aug;40(8):937-45. PMID 20108030
