Understanding Sensory Integration – Part 1

So what exactly is sensory processing difficulties or sensory integration difficulties? These are terminologies that have been tossed around almost interchangeably. The concept of sensory integration was first introduced by Dr. Jean Ayres 40 years ago with the available research at that time. She was an occupational therapist, mentor, author and researcher (Ayres, 1972). Dr Ayres introduced sensory integration theory. Since then there have been several researchers and scholars who have been working diligently on expanding the understanding of this concept. In this blog I will highlight Dr Ayers concept of sensory integration and in the subsequent blogs I will discuss the works of other prominent researchers in this field.

Dr Ayres described sensory integration as “a neurological process that organizes sensation from one’s body and from the environment to make it possible to use the body effectively within the environment” (Ayres, 1979, p.11). She introduced the concept that sensory integration is an important type of sensory processing where the central nervous system organizes the sensory information from the body and environment to make it a meaningful integral experience. Sensory integration is nourishing to the brain as it pulls everything together to allow the brain to use the different sensations to form perceptions, behavior and learning.

Dr Ayers describes how sensory integration begins in the womb as the fetal brain senses movements from the mother’s body. She also emphasized that sensory integration has a significant impact across our lifespan from infancy onwards involved in meeting developmental milestones such as crawling, standing, reading, dressing, showering, toileting to riding a bike to name just a few everyday activities. Ayres’ primary objective in developing sensory integration theory was to explain the underlying cause of the problem to determine the optimal mode of intervention. To understand this concept better, we need to pay attention to the different sensory systems that play a part in sensory integration.

The 8 main sensory systems that play a part in sensory integration are:

Tactile (Touch) input

The tactile system is our largest sensory organ in our skin which helps us to experience and understand our everyday senses from the word around us. Tactile input is responsible for interpreting different touch sensations (light, firm, vibrations), temperature differences and pain perception. Importantly, the touch sensation also warn you of dangers in the environment.

Example of symptoms of dysregulation:

Tags in clothing can be uncomfortable for a tactile sensitive child causing the child to strip or take off their clothing wherever they are or as soon as they get home. Seams in socks can be distressing causing them to take their shoes or socks off.

Proprioception input

Proprioceptive input is the sensation from receptors in joints and muscles that informs the person of where their body is in space for spatial orientation. This is also the sensation that is important for us to respond with appropriate force and kinesthetic awareness.

Example of symptoms of dysregulation:

When a child is under-responsive to proprioceptive input, you may see them opening a door or drawer with more force than needed. Or they may lay a heavy tap on your shoulder instead of a soft tap.

Vestibular input

The vestibular system informs your balance, spatial orientation and coordination of movement. Balance is a combination of signals form the eyes, inner ears, skin, muscles and joints.

The inner ear has three loops called the semicircular canals that are filled with fluid and sensory hair that inform us of three movements: up and down movement, side to side movement and tilting movements.

Example of symptoms of dysregulation:

When there is a dysregulation, this child may experience gravitational insecurity which my be displayed as a child being afraid of sitting on a swing or on a toilet especially with their feet of the ground.

Auditory (Sound) input

The auditory input is the processing and perception of sound in the brain whichis important for us to correctly interpret, hear and respond appropriately to the world around us.

Example of symptoms of dysregulation:

Some of these children are over aroused to sounds such as the vacuum cleaner, a dog barking, the flushing toilet, the had drier etc. These sounds can cause distress where the child has to either cover their ears, strikes out at someone to stop the sound, or darts to avoid the sound.

Gustatory (Taste) input

Gustatory is the perception of taste and flavors for the five main taste sensations which are sweet, sour, bitter, salty and umami. The gustatory system is important for ingestion and avoidance.

Example of symptoms of dysregulation:

Picky eaters have a limited range of foods that they will eat which may be due to the taste or texture of the food. This can contribute to ‘failure to thrive’ or have decreased nutritional intake.

Olfactory (Smell) input

The olfactory input is the ability to perceive and interpret odors. Smell like the other sensations is closely connected to emotions. A smell can either bring back good or bad memories of a place, event or person.

Example of symptoms of dysregulation:

Children with sensory issues can be very sensitive to smells, these children can be affected by the smell of perfume, paint, or even the smell of their own bowel movement can be offensive to them.

Visual (Sight) input

The visual input is the ability to see and decipher your environment. If visual information is not perceived and processed accurately it can be distracting and it will interfere with learning.

Example of symptoms of dysregulation:

Certain children may be hypersensitive to light where you’ll see them squinting. For some children reading from a white background is too glaring for them. Children with autism are generally are affected fluorescent light as it tends to flicker and can be very distracting for them. The use of colored overlays may assist in making it easier on their eyes


Interoception is the ability to perceive one’s own bodily sensations such as your gut, heart beat, respiratory sensation such as knowing when you are hungry or when you need to use the toilet.

Example of symptoms of dysregulation:

There is a disruption in the message being relayed that causes a delay in the processing of information resulting in the child not realizing they are getting hungry or that they need to use the toilet. This results in the child either getting upset when they do not get their food immediately. The delay in processing the information also affects the timing for going to the toilet on time resulting in toileting accidents.

Dr Ayers described sensory processing dysfunction as ‘traffic jam” in the brain. Here, sensory information gets tied up in traffic where some parts of the brain did not get the important sensory information to get the job done. Hence, this affects the brain’s ability to process or organize the flow of sensory information in a manner that would give the child good, precise, information for the world (Ayres, 1979). She introduced the concept of some children being under -responsive while there are others who are over-responsive. Examples of this would be a child stepping on hot pavement with their bare feet and not flinching. This child is under- responsive to the tactile sensation from the hot pavement. This is dangerous as the child sensory system is not alerting the child and heat from the pavement can blister the child’s feet.

In the next scenario is a child going to the beach and screaming because the child does not like the sensation of sand on their feet. This child is over-responsive to the sensation of sand which is not alarming to others. Dr Ayres was the first to highlight that when sensory information is not processed well, it leads to ineffective behavior and learning for the child. This leads to maladaptive behavior, when sensory information is not processed well, such that the child has difficulty handling or coping with the ordinary demands and stresses in the environment.

On a daily basis, a child with sensory processing dysfunction undergoes constant sensory bombardments which they are unable to control. For these children, every day is a constant battle trying to navigate through normal daily activities such as getting dressed, being on a bus or train with others, having a meal, trying to stay focused in a classroom or trying to play with other children. What’s most distressing and frustrating for these children is that others around them seem oblivious of their discomfort. What others around this child might see is a child withdrawing or overreacting to a situation. When really this child is going through distress and trying to protect him/herself.

Understanding the underlying sensory processing difficulties and how it may manifest as a behavioral response is key in managing these children and also teaching them self-management skills. It is also important to remember once the child’s sensory processing issues are being treated and managed, it is important to also help this child get desensitized by giving them access to the sensory adaptations such as headphones or allowing them to experience different textures with the child being in control when to wear or touch the items. This would help the child in learning self-management skills. Gradual exposure to different sensory sensations in the environment provides the child with opportunities to learn, develop skills, and adapt to the environmental needs. They would have a roadmap in their mind of what possibly to expect and which self-management strategies to use in adapting to their environmental needs.


Ayres, A.J. (1979). What is sensory integration? In A.J. Ayres, Sensory Integration

and the child (pp.1-11). Los Angeles: Western Psychological Services.

Krishnan, K.N.(2018). The SI Solution. The definitive family guide in thriving during sensory

integration dysfunction. Self Published.