A. Jean Ayres, Ph.D., an occupational therapist, first researched and described the theories and frame of reference that we now call sensory integration. Briefly, sensory integration is a process used by the brain to locate, sort, and make sense out of incoming sensory information. This process is important to successfully accomplish life tasks.
Ayres described sensory integrative dysfunction as a sort of “traffic jam” in the brain. Some bits of sensory information get “tied up in traffic” and certain parts of the brain do not get the sensory information they need to do their jobs. Children who have ASD may experience this.
For example, a child may scream when wearing certain clothing because her sensory system is hypersensitive to the sense of touch. This same child may crave bear hugs (deep touch) because her proprioceptive system is hyposensitive. (See Proprioception below.) These hypersensitive and hyposensitive sensations impact the child’s independent functioning in many facets of life, including peer interaction, attention at school, and activities of daily living at home.
Proprioception (sensation from joints, muscles and tissues that lead to body awareness), obtained by lifting, pushing and pulling heavy objects as well as engaging in activities that compress (push together) or distract (pull apart) the joints. It is the sense that allows a person to guide his arm or leg movements without having to observe the movement to make sure it is happening.
Vestibular (the sense of movement, centered in the inner ear), obtained by spinning and swinging and, to a lesser extent, any type of body movement or change in head position. It coordinates the movement of one’s eyes, head, and body and tells the body where it is in space. The vestibular sense is central in maintaining muscle tone, coordinating two sides of the body, and holding the head upright against gravity.
Tactile (sense of touch) obtained by providing a variety of input from textures, temperature, and pressure.
Auditory (what we hear and closely connected with the vestibular sense), obtained by listening to various types of music or natural sounds. Some auditory input can have an organizing and calming effect. Music containing 60 beats per minute can be particularly organizing, whereas irregular beats and contrasts in volume may be energizing.
Visual (what we see), can be used to calm or alert the system. Care must be taken that the child’s environment is not too visually stimulating or distracting.
Olfactory (smell) input can stimulate, calm, or send a child into sensory overload.
Taste, obtained by the use of sweet, salty, crunchy, or chewy foods, can help calm, alert, or organize the system.
Once the child’s sensory processing abilities and needs have been evaluated, the therapist may work with the educational team as well as the family to develop a sensory diet, a term coined by Patricia Wilbarger, OT. The sensory diet is a carefully designed personalized activity schedule that provides the sensory input a person’s nervous system needs to stay focused and organized throughout the day. Because sensory needs vary from individual to individual and from day to day, careful monitoring and collaboration is crucial. Components of a sensory diet might include brushing, swinging, heavy work (lifting, carrying), swimming, wearing weighted vests, wrist or ankle weights, wearing earphones, tactile play, trampoline jumping, chewing hard or crunchy objects, among many others.
Occupational therapists may also elect to use a system of tactile and proprioceptive input called the Wilbarger Protocol. This is a system using a soft bristle brush to provide carefully controlled sensory input, always followed by a deep pressure/joint compression system. While this protocol has been anecdotally reported to be effective in regulating sensory processing for some individuals, if done incorrectly, it can have harmful or dangerous results. Therefore, this procedure should only be used by trained personnel, and under the supervision of a trained occupational therapist.
Autism Research Institute
The American Occupational Therapy Association - Supporting Parents of Children With Autism: The Role of Occupational Therapy
Sensory Processing Disorder Foundation
SI Focus Magazine