The causes of Sensory Integration/Sensory Processing Disorder are not entirely known because the disorder is neurological and so very diverse. It was first recognized 40 years ago by A Jean Ayres, Ph.D., OTR.

Sensory Integration Disorder is a neurological disorder that results from the brain’s inability to integrate information received from the body’s sensory systems. Those particular systems are responsible for sight, sounds, taste, temperature, pain, position, and movement. The brain takes information it receives, analyzes the information, and tells the body how to react to the information. When a child has sensory integration the brain misinterprets the information it receives and tells the body to act in a different manner.

Basically, the brain must organize all of the information it takes in, categorize and process the sensations and attempt to move and learn “normally”. If the brain can not do that then the output is dysfunctional.

Sensory integration includes not only the five senses but also balance and movement.

Sight
Sound (auditory- with no diagnosed hearing problems)
Touch (tactile- input from the skin receptors about touch, pressure, temperature, pain, and movement of the hairs on the skin.)
Vestibular (input from the inner ear about equilibrium, gravitational changes, movement experiences, and position in space)
Proprioceptive (input from the muscles and joints about body position, weight, pressure, stretch, movement, and changes in position in space)
Oral
Smell
Auditory Language
Social, Emotional, Play, and Self Regulation: Sensory Integration is typically detected and diagnosed in children because SI can be obvious during early childhood activities such as tactile play, tumbling, and gross and fine motor skills. If Sensory Integration is not detected learning, development, and behavior problems can surface later and become more serious.