Autism and Sensory Processing Disorder

A paper recently presented at the International Meeting for Autism Research verified what many parents of kids with an Autism Spectrum Disorder (ASD) already know – that children with some form of autism often overreact to sensory stimuli. As with other studies that have shown that synesthesia is demonstrably "real" in the brain, being overwhelmed by sensory input is also evident in brain scans of kids with ASD. The researchers found that while separate sensations were processed normally, sensations occurring at the same time were not. The implication: People with ASD (especially children, who are not as used to bustling stimuli as adults) have legitimate challenges regulating their reaction to things happening in quick succession. (Here's a previous study with almost identical findings.)

Autism is similar, in this respect, to a condition known as Sensory Processing Disorder (SPD). A psychologist andoccupational therapist, the late A. Jean Ayres, first described the condition in 1972 as revolving around difficulty handling information coming through the senses: not just the five obvious senses but the equally critical proprioceptive and vestibular senses. These tell us, respectively, where our limbs are in relation to the rest of our body and how our body is oriented in space. Kids with SPD may be extremely sensitive to touch but not able to tell where the touch is coming from, for example. Their balance may be shaky and they may tend to bump into other people and things. They may not use the left and right sides of their body in a coordinated manner, and have trouble carrying out new or unfamiliar movements. Learning to write, color in the lines, put puzzles together, hit a baseball, ride a bike…all of these may prove problematic for a kid with SPD.

As the researchers at the International Meeting for Autism Research demonstrated 42 years after Ayres intuited it, some children’s brains have difficulty interpreting a sensation, especially if it comes on the heels of another, different sensation. While most of us take this for granted, kids with SPD feel overwhelmed, frustrated, confused, and/or tormented by stimuli on an ongoing basis. These feelings translate into problematic behavior: irritability; jumpiness; full-blown tantrums.

To their parents, teachers, and peers, this behavior occurs for no apparent reason. The children come across as some combination of withdrawn, inattentive, annoying, disrespectful, stubborn, unruly, or unpredictable. They may be considered learning disabled or written off as discipline problems. They may also be labeled as autistic – though it’s believed that most children with SPD are not autistic because they don’t experience breakdowns in the three areas that typify autism: language development, social affiliation, and empathy. Three quarters of kids with ASD, however (at least according to one oft-cited study) show significant signs of SPD, however.

Such children, for whom the moment-to-moment overlap of sensations may be something like a traffic jam in the brain, environmental sensitivity abounds. Things are perceived as too loud, too bright, too fast, or too tight. They may report what sounds like synesthesia, e.g., “I don’t like that shirt. It’s too spicy on the inside.” And such children often have highly reactive immune systems and a greater incidence of allergies than typical kids.

This package can be a pretty intense one for parents to deal with. But what of the traditional picture we have of the autistic child – the boy (it’s mostly boys) who’s just plain withdrawn and uncommunicative? It turns out there’s probably much more going on there that’s intense, too. More in my next blog post.