Jean Ayres developed the theory of sensory processing or sensory integration in the 1960’s and 1970’s to explain how the brain organizes sensory information (sound, sight, movement, touch, etc.) from the environment and responds in an adaptive or useful way.   Individuals with sensory integration dysfunction (SID) or sensory processing dysfunction (SPD) often have difficulty reacting appropriately  to their sensory experiences and, thus, adapting to changes in their environment. 

• Individuals can overreact (hypersensitive) and/or under react (hyposensitive) in response to their sensory experiences. 
• Individuals with these sensory skill challenges can find everyday activities difficult. 
• An inability to process and integrate sensory information can limit a child or adolescent’s performance in their daily tasks, throughout numerous environments. 

However, confusion abounds when discussing the term sensory processing/integration and the appropriate intervention approach.  There is confusing information and research regarding

• terminology,
• assessment,
• interventions,
• outcomes to be expected. 

Further, sensory integration/processing theory was developed on the idea that there is a “traffic jam” with the reception of the sensory information.  The actual nervous system and cognitive skills is assumed to be undamaged.  The theory has continued to evolve but given the complicated nature of a sensory integration/processing disorder, a thorough evaluation with physical examination, observation, interview, and standardized testing (if possible) is necessary from an experienced therapist.