Ideas
and concepts associated with sensory integration and Sensory
Integration Theory
Sensory integration is a
natural, neurologic phenomenon that occurs throughout the life span.
The brain takes in information from the sensory receptors of the
body (i.e., ears, eyes, skin, muscles, etc.), then processes and
organizes it, which results in integration of information for use.
This means that sensory integration allows the individual to act
adaptively (e.g., engage, function, learn, be comfortable in experiences
that are known or novel).
We are all "sensory processors;"
usually this occurs automatically, and we function well in our dynamic
worlds. If there is a disruption in sensory processing (e.g., caused
by lack of sleep), we may become grumpy and behave badly, have trouble
focusing on what we are doing, or become less coordinated. Fortunately,
for us this is a temporary condition. However there
are many possible "disruptors" that may have brief or
long term effects, and there are people who do not automatically
process sensory information effectively or efficiently.
We don't completely understand why all disruptions in the natural
process of sensory integration occur. We think that for some children
it may be a result of deprived environmental conditions (sensory,
motor, and social) that are associated with institutionalization,
as well as neurobiological factors influenced by heredity and environment
(e.g., toxins, malnutrition, etc.).
Sensory Integration Theory (SI),
developed by A. Jean Ayres, PhD, OTR, motivates many occupational
therapy assessment and intervention strategies. Initially, Dr. Ayres
studied children who had learning problems. Using insightful observation
and knowledge bases in development and psychology, she theorized
that higher brain functions such as reading
and skilled movement were impeded by poor sensory integration,
an outcome of neural processing in lower brain regions (e.g., brainstem
and midbrain). The problem is not in the
peripheral receptor mechanisms (e.g., ear, eye, touch, muscle, or
balance systems) but central processing of sensory information within
the brain.
Dr. Ayres particularly focused
on the body sensory systems: tactile (touch), vestibular
(movement, vibration, equilibrium), and proprioception (muscle
position, movement, stretch). She developed unique, sensory experiences
and equipment that provide powerful sensory input; this facilitates
neural processing necessary to sensory integration.
The improved neural capacity supports the child's
self-directed action (the child initiates and controls movement
that is neither passive nor imposed) in response to the environmental
challenge (the physical or social event occurring during therapy).
The performance of an intentional, successful behavior elicited
by an environmental demand is called an Adaptive Response/Reaction
(AR).
Poor sensory processing interferes
with the normal process of sensory integration which allows the
child to perform adaptive functions and to acquire higher learning.
The proposed patterns of Sensory Processing Disorders are: Sensory
Modulation Dysfunction (addressed later); Poor Sensory Discrimination:
difficultiess are associated with visual perceptual problems in
reading (seeing "b" for "d") audition (hearing
"berry" rather than "very"); and Dyspraxia and
Postural Disorders (addressed later).
Sensory Integration Treatment
involves providing intense sensory experiences that result in self-directed
performance of new, adaptive behaviors (e.g., an adaptive response).
Selection of specific sensory activities is based upon previous
assessment of the child's sensory systems, real-time awareness of
the child's state (e.g., organized/disorganized, alert, agitated),
and the affordances (characteristics such as suspended, stationery,
able to rotate, soft, etc.) of the equipment/activity to elicit
desired adaptive responses. This coupling of sensory input and
an adaptive response differentiates Sensory Integration Treatment
from other sensory-motor-based interventions. The process involves
a "reciprocity or dance" between the child and the therapist
that results in collaborative choices for use of equipment, activities,
and expected results. This allows child-directed activities,
not imposed or initiated by the therapist. Sensory Integration Treatment
is easily distinguished from therapy using sensory-motor activities
performed under the therapist's directions, choices, and prescriptive
results.