Updated: Jun 7, 2020
My conceptualization of autism includes some subtypes I find useful to consider. I watch for clues about whether the individual on the spectrum leans toward under-reactivity or over-reactivity.
Under-reactivity means that the person misses important information in his environment. This may include external information like social cues from others, someone calling his name, or whether his clothes are on inside out. The under-reactivity could also be about internal information like his own emotions and motivations, whether he is in pain, or whether the lights are on or off.
Over-reactivity occurs when the individual has a heightened nervous system response to external and/or internal information as above. He experiences the world as intense and overwhelming.
Other individuals seem to have a mix of both under and over-reactivity, perhaps across varying inputs (for example, he may be over-reactive to lights but under-reactive to the facial expressions of others).
It's helpful to consider this trend in each individual because the recommendations for each will be different. For the under-reactive individual, inputs that are activating and can help with behavioral momentum are important. For the over-reactive individual, inputs that are calming and strategies for pacing and resilience will be most important.
WHAT DOES UNDER-REACTIVITY LOOK LIKE IN THE SENSORY REALM?
Consider each of the EIGHT sensory symptoms that should be assessed for each ASD individual:
Under-reactivity in the sensory realms may look like:
1. Vision: not noticing that he is sitting in the dark
2. Hearing: not noticing the fire alarm
3. Touch: being described as an "adventurous eater" -- "He'll eat anything" [Most people should have some range of reactivity to the texture of foods. Eating "anything" probably means there is a lack of discrimination about the texture or other aspects of food]
4. Taste: he puts "tons of salt on everything"
5. Smell: doesn't notice strong noxious smells
6. Vestibular (movement of the body through space; ears/head must move through space): doesn't react to roller coasters positively or negatively
7. Proprioception (body position): may be under-aware of body position cues -- the person who falls off a chair for no reason, bumps into others while walking, puts too much or too little pressure on objects [breaks pencils, drops things]
8. Interoception (inner physical states like pain, temperature, hunger/thirst, bowel/bladder, illness): breaks a bone without noticing, doesn't drink fluids to the point of being hospitalized many times for dehydration and urinary tract infections
Recognize the signs and patterns of autistic characteristics in each individual to understand behavior and to think of possible interventions or compensations.