Sensory Modulation

Sensory modulation and assessment is a specialist skillset, unique to the profession of occupational therapy, and highly applicable to the practice of psychotherapy and processing trauma. Have you ever noticed the impulse to fidget when struggling to concentrate, or witnessed the intuitive desire to rock an unsettled baby? Have you ever felt more connected to your body after a run, enlivened by a cold ocean swim, or bothered by a space that looks ‘too cluttered’?

Our sensory systems intelligently connect us to the world we live in through receiving, processing, organising and making meaning of sensory information. Our bodies process bountiful amounts of sensory information in each moment, most of which we are not consciously aware of, and this information helps our internal bodily functions to operate as well as helps us to relate to the external world. Our senses are highly linked to the processing of memories, also, and therefore can support us find, and trigger us into, different emotional states very quickly.

The following poem captures something of our sensory experience when we stop and come alive to our senses…

For The Senses, by John O’Donohue

May the touch of your skin Register the beauty
Of the otherness
That surrounds you.

May your listening be attuned
To the deeper silence
Where sound is honed
To bring distance home.

May the fragrance
Of a breathing meadow
Refresh your heart
And remind you you are
A child of the earth.

And when you partake
Of food and drink,
May your taste quicken
To the gift and sweetness
That flows from the earth.

May your inner eye
See through the surfaces
And glean the real presence
Of everything that meets you.

May your soul beautify
The desire of your eyes
That you might glimpse
The infinity that hides
In the simple sights
That seem worn
To your usual eyes.

Consider, for a moment, walking in the rain through a forest trail. Perhaps there is a sense of the cool air and the wetness of water droplets that meets your skin. You might hear the sounds of rain splashing on the floor and on the leaves of trees, like an applause from a great crowd of people. Your ears sense the thunder deeply rumbling in the sky. You may taste the crisp, freshly falling water if you allow yourself to open your mouth to the sky; see the grey colour of the rolling clouds and the misty, sparkling light of rain drops meeting your coat. Take a deep breath in through your nose and you may smell the petrichor of the damp forest nearby. All of this, as you feel yourself moving, your feet beating against the wet ground with every step you take through this magical and sensual place.

The senses.

For a long time, it was believed that humans had 5 senses. Researchers have since discovered that there are many more sensory systems that our bodies utilise, making sensory processing a complex neurophysiological topic. To keep things simple but informative, here we will discuss 8 sensory systems that can be helpful to become aware of.

Most of us are familiar with the first five senses….

Touch – what we can touch

Taste – what we can taste

Smell – what we can smell

Hearing – what we can hear

Vision – what we can see

We also have 3 more senses that we call our “internal” senses….

Movement (vestibular) – information from the inner ear that tells us about our body movement e.g. running, rocking, swinging, bouncing, tipping upside down etc.

Awareness of the bodies position in space (proprioception) – information from our muscles, body and joints that tells us about the positioning of our body e.g. if you close your eyes, proprioception will help you to know what position your body is in/where your limbs are without looking at them.

Perception of sensations from inside the body (interoception)- includes the perception of physical sensations related to internal organ function such as heart beat, respiration, satiety, as well as the autonomic nervous system activity related to emotions.

How does the body process sensory information?

The body first registers or recognises sensory information and then sends this information to the brain (for example, noticing a neighbours lawn mower start outside when you are trying to concentrate on reading the newspaper). The brain discriminates (differentiates between the lawn mower and what your eyes are seeing), then modulates (organises) this information to help your level of arousal to be optimal so that you can continue going about your daily activities.

Huh? What does arousal have to do with any of this?!

When we refer to the term, arousal, in a sensory modulation context, we are talking about the level of alertness of our nervous system. Arousal levels fluctuate throughout the day, which is important, because we need different levels of arousal for different activities. When we find the ‘just right’ level of arousal for a particular activity we are doing, we call this the optimal level of arousal. For example, optimal arousal would be different for driving, than when we are sleeping.

What is sensory modulation?

Sensory modulation is what our bodies do to regulate the intensity and types of sensory information that we process so that our arousal levels are ‘just right’ which helps us to function in a healthy way. In the newspaper reading example mentioned earlier, this would look like the nervous system recognising the loud noise, but reducing the intensity of the noise in your conscious awareness to allow you to focus on your reading. You might see then how, if this process were to be interrupted by feelings of overwhelm and distress, our nervous system might struggle to support us to effectively complete meaningful tasks in our life. The good news is, we are able to support our bodies in this process by understanding our individual sensory preferences and thresholds and manipulating the sensory information that we expose ourselves to in very particular ways. This can have very positive effects on our mood and arousal levels.

Is less really more?…or less?

Sensory thresholds refer to the amount of information that your brain needs to get from the environment before it responds to it. Our thresholds can be different for each of our senses, at different times of the day, and when we are in different environments. For example, you may find that strong smells make you feel overwhelmed easily (you have a low threshold for smell) but that a strong hug helps you to feel calm (you have a high threshold for proprioception/deep touch). This may be the case when you are at home, but when you are at the shops, it may change again. These thresholds inform our sensory preferences – what we ‘like’ and ‘don’t like’.

Are you a big cup or a little cup?

The analogy of “big cup, little cup” can be helpful to visualise how sensory thresholds work. The cups represent the appetite you have for each of your senses - how much sensory stimulus you need to receive for your arousal levels to remain optimal. Optimal arousal for performance occurs when our sensory cup is full. When it is empty- we may need more stimulus to function well, and when it is overflowing, we will be overwhelmed and again lose the capacity to function well. Let’s take one of our senses - say proprioception, and consider what from a sensory perspective will regulate our system to an optimal arousal level.

A little feels like a lot.

A person with a small cup for the proprioceptive sense might become overwhelmed with the sensations of moving, exercising, lifting objects or being hugged. We would say that this person has a lower threshold for proprioception. Gentler forms of exercise, and alternative forms of physical connection with others may be more preferable for this person.

A lot feels like a little.

The “big cup” refers to a person with a high threshold for sensory input- who therefore needs more sensory stimulus to be at an optimal level of arousal for performing. Using the same proprioceptive example, gentler movements and body contact may not be enough to feel grounded for someone with a high threshold for these sensations - therefore they may find contact sports, tight hugs, deep stretching and lifting weights to be more helpful in regulating themselves.

Sensory preferences and behaviour

There are general patterns of behaviour associated with different groups of sensory preferences. People might actively seek out more sensory stimulus or seek out an escape from overwhelming sensory stimulus. Some people may be less active in this process, feeling stuck and overwhelmed, or removed and under-stimulated. These are all contextual and individual to each person.

What can we do about it?

Occupational therapists are trained in the assessment of sensory processing for individuals. There are many approaches to calming and alerting your nervous system, using a trauma-informed sensory lens, to find the optimal level of arousal that is unique to you, your environment, and the activities you partake in. Occupational therapy can offer a holistic approach to supporting you to develop a mindful awareness of your sensory system, its preferences and needs, so that you can feel more regulated and alive.

So…which cup are you?

Understanding what your sensory preferences and thresholds are, can be the first step in supporting your body and mind to reach optimal levels of arousal for different activities and tasks throughout your day.

Would you like to experience some of this in therapy?

If this approach interests you, and you would like to know or experience some of this, you are welcome to contact us via the button below.

Thank you for reading.

Warmly,

Dylan.