Sensory Integration: Understanding the Power of the Eight Senses
We're often taught from a young age that there are only five senses: Sight, Hearing, Taste, Smell and Touch. This makes sense as these five senses are linked to visible sense organs such as the eyes, ears, mouths, noses and skin. However, our ability to sense is much more complex than this. What would you say if I told you we actually have eight senses?
If we are able to understand all the senses involved in being human, we can better connect, understand and help those around us, whether we are a parent, a therapist or just casual observers. In this article, we will discuss the eight senses, which will help you in your everyday life and help those who are important to you.
What are the eight sensory systems:
As discussed, we have the basic five senses which take in sensory input, which include:
Sight (visual system)
Taste (gustatory system)
Touch (tactile system)
Hearing (auditory system)
Smell (olfactory system)
We also have three less talked-about senses
6. Vestibular system (sense of head movement in space
7. Proprioceptive system (sensations from muscles, ligaments and joints of the body)
8. Interoceptive system (sensation from internal organs)
Note:
Depending on how you define senses, how specific you want to get into each category above and what kind of receptors we have in our body, we technically have many more senses.
Senses special: Doors of perception 2005
What is sensory integration?
Sensory integration refers to the brain's ability to receive, process, and organize sensory information from the environment and the body's own sensations, in order to produce appropriate responses and actions. The sensory information comes from the five senses - sight, hearing, taste, smell, and touch - as well as from the proprioceptive and vestibular systems, which provide information about body position, movement, and balance.
Sensory integration plays a crucial role in our ability to interact with the environment, engage in meaningful activities, and perform daily tasks. It allows us to filter out irrelevant information, focus on important cues, and respond appropriately to different sensory stimuli. When there is a breakdown in sensory integration, it can lead to sensory processing difficulties, which can affect a person's behaviour, emotions, and ability to function in everyday life.
What are the five basic senses?
Sight (visual input)
Our eyes take continuous visual information about our surroundings. Our visual system helps us know what colour, shape, motion and texture things are. After receiving all this information the brain then combines these features to create a visual representation of the world around us. We also use the visual system throughout the day for basic tasks such as recognizing faces and objects to more complex tasks such as reading, driving and navigating through the environment. The visual system also plays a vital role in our emotions and social interactions, as facial expressions and body language provide essential cues for communication.
2. Taste (gustatory input)
When we eat, drink or put something in our mouths, we use our taste buds to discern the taste of something. Flavours are typically broken down into five basic tastes: sweet, sour, salty, bitter, and umami (savoury). We use the taste sense to identify different foods, determining whether a food is safe to eat and what tastes we enjoy or dislike.
3. Touch (tactile input)
Touch is the sensory input that allows humans to perceive physical contact with objects and surfaces. Specialized receptors in the skin mediate the sense of touch called mechanoreceptors, which also detect pressure, temperature, vibrations and textures. These signals are then sent to the brain, which processes and interprets the information to create a sense of touch. Throughout our day-to-day life, we use our sense of touch to explore our environment, detect temperature changes, feel pain or discomfort, and communicate with others through physical contact. The sense of touch also plays a vital role in our emotional and social interactions, as physical touch can convey feelings of comfort, affection, or support.
4. Hearing (auditory input)
The sense of hearing, allows us to perceive sounds and interpret them as speech, music, or other sounds in the environment. Without getting into the technicalities, every sound creates vibrations called sound waves. If these sound waves reach the ear, then they are detected by hair-like cells in the cochlea. The hair cells convert the sound vibrations into electrical signals, which are then interpreted by the brain. The importance of hearing can not be understated, as it also allows us to communicate and detect danger. Depending on the importance of the sound, it may also just be interpreted as background noise by the brain, which we can tune out. Notably, the sense of hearing is essential for speech and language development and allows us to communicate with others through spoken words and nonverbal sounds.
5. Smell (olfactory input)
Smell is the sense that allows humans to perceive different odours and scents in the environment. We use smell for various purposes, such as identifying different types of food, detecting smoke or gas leaks, and enjoying the aromas of fragrances or perfumes. The sense of smell also plays a crucial role in our emotional and social interactions, as certain scents can trigger memories and evoke feelings of comfort, nostalgia, or excitement. In addition, smell is also processed by the amygdala and hippocampus, which are involved in emotional processing and memory formation.
What are the three lesser-known sensory systems?
As previously mentioned, the three lesser-known sensory systems are the vestibular system, the proprioceptive system and the interoceptive system. Even though they are lesser known, it is important that we understand their role in our sense of understanding of the world around us for communication and appropriate bodily functions and movements. We will first explain what each of the systems is and then describe an example of how our body uses these systems in everyday life.
6. Vestibular system (sense of head movement in space)
The vestibular system is a sensory system responsible for providing us with a sense of balance and spatial orientation. The vestibular system is located in the inner ear and comprises three semicircular canals and two otolith organs (the utricle and saccule).
The semicircular canals detect rotational movements of the head, such as turning or tilting, while the otolith organs detect linear movements, such as acceleration or deceleration. When the head moves, the hair cells in the vestibular system are stimulated and send signals to the brain about the direction and speed of the movement.
We use the vestibular system to maintain balance and stability while standing, walking, running, or engaging in other physical activities. The vestibular system also helps us navigate through our environment by providing us with information about our position in space and our orientation relative to gravity.
A dysfunction of the vestibular system can lead to balance problems, dizziness, vertigo, and other symptoms that can affect a person's quality of life.
Vestibular example:
Imagine you are walking down a narrow, winding path on the side of a steep hill. As you turn a sharp corner, your head and body tilt to the side to maintain your balance and prevent you from falling off the path. Your semicircular canals in the inner ear detect the rotational movement of your head and send signals to your brain, which then adjusts the firing rates of the muscles in your legs, torso, and neck to keep you upright and stable. At the same time, the otolith organs in your inner ear detect the changes in linear acceleration and gravity as you move downhill and help to keep you oriented and balanced in space.
All of this happens seamlessly and automatically, thanks to the work of your vestibular system. Without it, you might feel dizzy or disoriented or have difficulty maintaining your balance and stability on the path.
7. Proprioceptive (sensations from muscles, ligaments and joints of the body)
Diagram of proprioceptors
Proprioception is the sense that allows us to perceive the position, movement, and orientation of our body parts without relying on visual or auditory cues. It is also known as the "body sense" or "body awareness" and is mediated by sensory receptors in muscles, tendons and joints
When we move our body, the sensory receptors called proprioceptors in our muscles and joints send signals to the brain about the position and movement of our limbs and body parts. This information is integrated with other sensory information, such as visual and auditory cues, to create a coherent sense of body awareness.
We use proprioception for various purposes, such as maintaining balance and coordination during physical activities, performing fine motor tasks that require precise movements, and adapting to changes in the environment, such as walking on uneven surfaces or handling objects of different sizes and shapes.
Proprioception also plays an essential role in our ability to perceive and control our body movements. It is essential for activities that require complex motor skills, such as sports, dance, and musical performance. Dysfunctions of the proprioceptive system can lead to movement disorders, such as ataxia, dyspraxia, and apraxia, affecting a person's ability to perform everyday activities and participate in physical activities.
Proprioception example:
Finger nose proprioceptive test
If you were to close your eyes and put your finger just in front of your nose, how would you know how far away your finger is from your nose? The answer is through the proprioceptive system. Proprioception allows your body to have spatial awareness of your body and the objects around you. For another example, if you were to get up and go for a walk, your sense of sight helps stop you from walking into obstacles; however, it's your proprioception system that tells your brain where your feet are so you can walk without falling over yourself.
8. Interoception (sensation from internal organs)
Interoception is the sense that allows us to perceive and understand the internal state of our body, including sensations from our internal organs, such as the heart, lungs, stomach, and bladder. It is mediated by sensory receptors located in the walls of these organs, as well as in the bloodstream.
When we experience changes in our internal state, such as hunger, thirst, pain, or discomfort, the sensory receptors in our organs send signals to the brain that are integrated with other sensory information to create a coherent sense of bodily awareness.
Humans use interoception for various purposes, such as regulating bodily functions, such as heart rate, blood pressure, and breathing, as well as monitoring and responding to changes in our internal environment, such as fluctuations in blood sugar levels or changes in body temperature.
Interoception also plays an important role in our emotional and psychological well-being, allowing us to perceive and respond to our own emotional states, such as anxiety, stress, or arousal. People who have difficulties with interoception may experience various symptoms, such as digestive problems, chronic pain, or difficulties regulating their emotions.
Interoception example:
Imagine you've been working on a project for hours without taking a break. As a result, you start to feel hungry, and your stomach begins to rumble. The sensation of hunger is an example of interoception, as it arises from sensory receptors in the stomach and digestive tract that detect changes in the levels of hormones and nutrients in the bloodstream. In response to this sensation, you might take a break and grab a snack to satisfy your hunger. This is an example of how interoception can drive behaviour and influence decision-making, as it provides crucial information about our internal state and needs.
How does sensory processing relate to conditions such as Autism and ADHD?
For children with autism, sensory processing differences are a common symptom. They may have hypersensitivity (overreacting to specific sensory inputs) or hyposensitivity (underreacting to certain sensory inputs) to different sensory experiences, such as sounds, lights, textures, smells, tastes, and movements. These differences can cause discomfort, anxiety, or distraction, impacting their ability to focus, communicate, socialize, or learn. For example, a child with autism may be sensitive to loud noises and cover their ears or may be unaware of their own body sensations and have difficulty with self-regulation.
For children with ADHD, sensation may play a role in their difficulty with attention and impulsivity. They may seek out stimulation or have a low threshold for boredom, which can lead to distractibility or hyperactivity. For example, a child with ADHD may fidget, tap their feet, or play with objects to regulate their arousal level. On the other hand, they may also be sensitive to external distractions, such as noise or movement, which can interfere with their ability to sustain attention.
It's important to note that every child with autism or ADHD is unique and may have different sensory profiles and needs. Some children may benefit from sensory integration therapy, which involves providing controlled sensory experiences to help them regulate their responses. Others may benefit from sensory accommodations, such as using noise-cancelling headphones or providing a quiet space to retreat to. An occupational therapist can do a sensory profile which can help identify what kind of senses a child is over-responsive or under-responsive to and what sort of sensory pattern they have.
What are the different sensory patterns?
Sensory Sensitive: Sensory sensitivity refers to being highly responsive to sensory input, meaning that individuals may notice sensory stimuli more readily and experience them more intensely than others. Examples of sensory sensitivity might include feeling overwhelmed by loud noises, disliking certain textures of fabrics or foods, or being easily distracted by bright lights.
Sensory Avoider: Sensory avoidance refers to actively avoiding or withdrawing from sensory input that is uncomfortable or overwhelming. For example, a sensory avoider might avoid going to crowded places or wearing clothes with certain textures that they find uncomfortable.
Sensory Seeker: Sensory seeking refers to actively seeking out sensory input, often in a way that might seem intense or risky to others. For example, a sensory seeker might seek out roughhousing or jumping activities to get a sensory "buzz" or might enjoy eating spicy or sour foods for sensory stimulation.
Low registration: Some individuals may have a delayed or slower response to sensory input, meaning they may not register or notice sensory stimuli as quickly as others. This can make it difficult for them to respond appropriately in certain situations. For example, someone slow to register sensory input might not notice when someone is calling their name or might not feel pain or discomfort as quickly as others.
Frequently asked questions
What is a sensory diet?
A sensory diet is a personalized plan that includes a series of activities, exercises, and sensory experiences designed to meet the specific sensory needs of an individual. It is a term commonly used in occupational therapy to help individuals with sensory processing difficulties regulate their sensory responses and function more effectively in their daily lives.
The goal of a sensory diet is to provide an individual with the right amount and type of sensory input needed to help them feel more organized, focused, and calm. This can include a combination of activities that provide sensory information in the areas of touch, movement, taste, smell, and sound, such as deep pressure activities, bouncing on a therapy ball, chewing gum, or listening to music.
Sensory diets are tailored to the individual's specific sensory needs, preferences, and interests and are often incorporated into daily routines and activities. They are usually created by an occupational therapist with experience working with individuals with sensory processing difficulties.
It's important to note that a sensory diet is not a one-size-fits-all approach, and it may take some trial and error to find the right combination of activities and sensory experiences that work best for an individual
What is brushing for sensory integration?
The Wilbarger Protocol (Brushing), also known as the Wilbarger Deep Pressure and Proprioceptive Technique (DPPT), is a sensory integration therapy technique used to address sensory processing difficulties in individuals with sensory modulation disorders, including those with autism, ADHD, and sensory processing disorder.
The protocol involves using a specific brushing technique to provide deep pressure input to the skin, followed by joint compression to provide proprioceptive input to the muscles and joints. This is done using a soft-bristled brush and applying firm pressure to the skin in specific patterns on various parts of the body, such as the arms, legs, back, and head. The protocol is typically performed multiple times a day and is often combined with other sensory integration techniques to help individuals regulate their sensory responses.