Does A Hyperstimulating Environment Cause ASD?

In a response to a recent post I was asked if I thought that a hyperstimulating environment could lead to ASD. I thought this topic deserved more than a simple response. So, here are my thoughts, but I am very open to hearing yours...

First, though neuroscientists often talk about brain development as if it is a straightforward thing, it is important to remember that the brain does not develop in a vacuum. The environment that the child is placed in has a great influence on how the brain subsequently develops. The brain is capable of setting up circuits based on what the child learns about it's environment.

Arguably, children growing up in recent years are being exposed to an ever more diverse and stimulating environment packed with stimuli to process from very early on. For example, my sister recently complained to me about how difficult it was to find a simple toy for my nephew that didn't blink or make noise or move around in a sporatic fashion.

Thus, if, as I have suggested that a child who is predisposed to develop autism has a brain that is set up to be "hyperplastic," meaning it responds very easily and quickly to it's envioronment and is capable of changing brain connections easier than a neurotypical individual, then it would seem that an overstimulating environment, such as the one our children are growing up in right now would be the "perfect storm" for leading to the brain changes that I would suggest lead to the behaviors of ASD.

Specifically, in the child who is predisposed to have ASD, his brain may be more reactive to novel stimulation and once activated, may have difficulty shutting itself off. This has the potential to lead to exceptional abilities in specific domains, but also limits the skills that require coordinated efforts of multiple systems (e.g. social and communication skills).

This would also be consistent with the reported increase in prevalence over the past several years.

Is there any truth to this theory? Who knows. It would be hard to test experimentally, however, it is true that many children with ASD seem to be hypersensitive to stimuli in the environment (sounds, lights, tactile sensations, etc.) and we need to be aware that the brain is developing and changing within this context and do our best to foster healthy neurodevelopment. Now the next question is "what type of environment leads to healthy neurodevelopment." Unfortunately, as neuroscientists we have more questions than answers, but we are getting there and when I know the answer to that question, I will let all of you know!