Sensory Integration is the ability to perceive, attend, and respond to sensory information. It is the organisation of sensation for use. Sensory Integration therefore needs effective intake and interpretation for an appropriate reaction to that particular stimuli.
Sensory Integration Dysfunction was first identified by Dr. Jean Ayres, an Occupational Therapist who noticed children struggling with functional tasks, but who did not fit into specific categories of disability commonly used in the 1960 - 1970's.
These children did not have clear cut diagnoses, but were obviously having difficulty with work behaviour, self-care and recreational activities.
She saw the challenges as being neurologically based and developed the term "Sensory Integration Dysfunction" to describe the problems faced by children whose brains do not consistently receive, process or respond to sensory input (from their own body and from the environment) appropriately. This means that they will not have the adaptive functional behaviours that make it possible for them to uses their body effectively within the environment.
There are traditionally 3 types of sensory input that comprise the cornerstone of the SI approach. These are the Tactile, Proprioceptive and Vestibular systems.
Tactile is the sense of touch, and is especially regulated through the more sensitive skin areas such as the hands, feet, mouth and head. It tells us about texture, size shape and temperature and helps us distinguish between threatening and non threatening touch sensations.
Proprioception is an umbrella term for the sense of body position and is involved in body awareness in space, planning and coordinating movements. This is also connected to emotional security and confidence. Proprioceptive input is sent to the brain through receptors in the muscles, joints, tendons and ligaments.
The Vestibular system is made up of sense receptors in the inner ear, as well as the fibres of Cranial Nerve VIII (Vestibulocochlear) connected to the internal brain structures. This determines the quality of balance and movement. It provides information about gravity and space, balance and movement, and about our head and body position in relation to the surface of the earth.
Sensory Integration Theory shows that the ability to modulate sensory input through these three systems has a powerful impact on the development of functional skills. They impact on the regulation of muscle tone, balance, motor control, postural stability, visual perception, visual motor control, auditory language skills and attention. Sensory Integrative Therapy appears to be particularly effective for helping patients with movement disorders or severe under- or over- sensitivity to sensory input.
For example: you are sitting near an open window reading as the sun goes down. It begins to get both cool and dark in the room, and your brain registers that visual and tactile/temperature information. The brain processing this information then attaches meaning: I can't see, I am cold. You then identify solutions: I need to close the window, turn on a light, get a sweater. The "adaptive response" is the actual standing up, walking over to the window, reaching up, pulling it down, locking it etc.