Sensory Integration in Autism

Making Sense of the World From a Different Perspective

Despite what teachers persist in teaching, humans have seven senses, not five. We are all aware of the five senses (vision, hearing, taste, smell, and touch) that alert, excite, sooth, satisfy, irritate, and inform us about the world around us. It is our internal body senses however that enable us to interact with our environment in a controlled and purposeful manner, thus making sense of the input we take in from our external senses.

Imagine seeing and smelling a fresh-baked apple pie placed in front of you, but not being able to plan or execute how to reach out, pick up a fork, and get it to your mouth to taste it? If you were getting inadequate input through your sense of balance and ability to hold a posture against the pull of gravity, you would fall flat on your face in the pie every time you leaned forward to pick up the utensil. If you received limited input to your muscles and joints (as you do when your arm or leg "falls asleep", you most likely, due to poor coordination, would lose food off the fork on the way up and end up poking yourself in the nose despite your intent to end up with it in your mouth... that is if you could maintain your grasp on the fork due to poor tactile "feel" of the fork in your hand. If you were lucky enough to get it to your mouth without falling down, it is quite likely that you would end up choking on the pie as it slides down your throat because of the inadequate tactile input in your mouth that helps you know where the food is as you attempt to chew and swallow it. All that for one bite of pie!

The body senses are just as important, if not more, to one's ability to function, much less enjoy ones experiences, in the world. Sensory Integration Dysfunction, very common in those on the spectrum, can make routine, daily events extremely difficult. In order to compensate for the poor sensory input and feedback that makes life easy, the individual with Sensory Integration Dysfunction needs to "think" their way through tasks that would be easy and automatic for the rest of us. That is extremely fatiguing. No wonder so many of those on the spectrum are exhausted, or "crash", so much! Sensory processing challenges are only the beginning of the challenges experienced by those on the spectrum. Below are some areas of the brain that researchers feel are not functioning in the same way that the neurologically-typical brain functions. Soon I will add some of the bio-chemical differences that can make life even more difficult to cope with for those on the spectrum.

Brain Structures
Involved in Sensory Processing
that have been Linked to Autism

  • Limbic System - maintains homeostasis or constant environment in the body

    • Amygdala - controls aggression and emotions; responsive to sensory stimuli as well as emotional or fear-related stimuli; mediates (recognizes) the recognition of fear and certain other emotions in others, including multiple emotions; stores emotional memories; involved in motivation
    • Hippocampus - responsible for learning and memory; results in stereotypic, self-stimulatory behaviors and hyperactivity when damaged
  • Cerebellum - improves control of balance, body position, and movement in space; stores memory for certain types of simple learned responses; smoothes and organizes voluntary movements (including speech); involved in speed/rhythm.
  • Brainstem - contains "activating" system which alerts the cortex in a general way about arriving information (which is then matched or not matched with memories stored in the Hippocampus leading to arousal if the input if novel or inhibition if the input is familiar); site of cranial nerve input from tactile, auditory and vestibular senses.
  • Parietal lobes - assembles information (letters - words- thoughts); involved in "knowing"
  • Frontal Lobe - involved in planning, decision making, and purposeful behavior; apprises situation as threatening or not and facilitates adaptation; helps focus attention