Many of us are aware of the term sensory deprivation and its association with Float tanks, but is this term accurate to describe the true float experience?
Firstly, let’s look at the definition of ‘Sensory Deprivation’ taken from the Collins dictionary,
Sensory input is greatly reduced during a float session, no light, no sound, we can’t really smell much nor taste anything in the float environment. In addition to this, once we lose sensation of water around us then our tactile system or sense of touch diminishes to a degree.
These all form part of the five basic sensory systems,
3. Olfactory (smell) system
4. Gustatory (taste) system
5. Tactile system
But you also have the following:
6. Vestibular (Sense of head movement in space) System – The vestibular system contributes to balance and orientation in space. It is the leading system informing us about movement and position of head relative to gravity.
The vestibular system contains three semi-circular canals, which are approximately at right angles to each other: the horizontal canal, which detects rotation around a vertical axis (as when you do spins in ice skating), the anterior semi-circular canal, detects movement in forward/backward plane as in a nodding movement. The posterior canal detects movement in a frontal plane as in when doing a cartwheel.
The canal on each side has an almost parallel counterpart on the other side. Each pair of canals works in a push-pull fashion: when one is stimulated, its partner is inhibited. Together the partners allow us to sense rotation in all directions.
7. Proprioceptive (Sensations from muscles and joints of the body) System – The proprioceptive system senses the position, location, orientation and movement of the body muscles and joints. Proprioception provides us with the send of the relative position of neighbouring parts of the body and effort used to move body parts.
8. Interoception – The eighth, often neglected sensory system is the Interoceptive System. Interoception refers to sensations relate to the physiological/physical condition of the body. Interoceptors are internal sensors that provide a sense of what our internal organs are feeling.
Interoception detects responses that guide regulation, including heart rate & respiration. Interoception works the vestibular and proprioceptive senses to determine how an individual perceives their own body.
Well-modulated interoception helps the individual detect the proprioceptive and vestibular sensation normally.
Interoception is associated with autonomic motor control and is different to mechano-reception (The ability to detect and respond to certain kinds of stimuli – notably touch, sound and changes in pressure or posture – in your environment) and proprioception (in the muscles and joints).
Interoception creates distinct feelings from the body including pain, temperature, itch, muscular and visceral sensations, hunger, thirst and the need for air.
Essentially, we have both external and internal senses, during a standard float session the sensory input for your external senses is minimised as we already know. What we now know is that once these senses have been dampened, we become more aware of our internal senses through interoception.
Let’s break it down and look at the different stages during a float session and how this affects your different senses.
*This is based on a 60 min float session with 10 minutes of music at the start of the session and 5 minutes at the end, 45 mins of silence and with the lights in the pod off and the lid closed, water temperature is 35.5 degrees Celsius.
The first 10 minutes: Music will play to help ease you into the session, at this point your auditory senses will be active.
10 – 20 minutes: You will initially be aware you are in water as you are trying to get into a comfortable position and allowing the water to settle around you. At this point your tactile system will be active.
From here on in things get interesting…. Assuming you have the lights off in the pod and no music.
20 minutes – 55 minutes: Now, around the 20 minute mark you will hopefully have settled into a comfortable position and the following will have happened.
All five basic sensory systems will have had their input greatly reduced.
1. Visual – No external light source, the only light source being produced from phosphenes inside your eye. A phosphene can be defined as the perception of light with no light actually being present. This entoptic (within-eye) phenomenon can include the perception of colours, flashes of light, and dots of light and dark that are not physically present.
2. Auditory – No external sounds, but there are other sounds which I will discuss below.
3. Olfactory (smell) system – You shouldn’t be able to smell anything in the clean, neutral environment of the pod.
4. Gustatory (taste) system – Unless you have eaten or drunk something with a strong taste you really won’t be tasting anything.
5. Tactile system – The reduction of the other sensory inputs is quite apparent, whereas the reduction of the tactile system is subtle. This is where you lose sensation of being in water, as your skin temperature and water temperature are the same. Once the tactile system is blissfully unaware it is in water, your internal senses kick in and you become more aware of your body’s internal processes.
Let’s break these down into the different parts so we can get a better understanding of what is going on.
During this period many people report the sensation of spinning around, drifting towards the left or right and on occasion the sensation that they are floating downstream. We have even had a few people state that they felt they were standing up during their Float session. This is all whilst they are lying still in the water, why does this happen?
This is all down to your vestibular system and proprioceptive system; we know the vestibular system contributes to balance and orientation in space and the proprioceptive system senses the position, location, orientation and movement of the body muscles and joints.
Astronauts experience similar sensations of disorientation during their first few days in the microgravity of space. A floater will not experience the same microgravity in a float pod as gravity is still exerting a force on the body, but the dense Epsom saltwater places the body in a balanced state.
With the sensation of being in water removed and the action of floating on the water this confuses the vestibular system and proprioceptive system, with both systems trying to work out which way the body is orientated and the position of the arms, legs and head as they are not moving. The sensation of spinning does not last long, but the feeling of floating or being suspended continues and there is a smaller amount of disorientation which adds to the sensation of floating.
We have briefly touched upon the vestibular and proprioceptive systems in relation to our physical position within this weird and wonderful alien environment of the float pod. The final sensory system and probably one of the most important is the interoceptive system, as I stated earlier ‘Interoceptors are internal sensors that provide a sense of what our internal organs are feeling.’
Some researchers believe that our perceptions of wellbeing, energy and stress are based on sensations representing the physiological condition of our bodies. They suggest that interoception is a foundation of subjective feelings, emotion and self-awareness. There is evidence that the anterior insula-cingulate system may integrate interoceptive information with emotional salience to form a subjective representation of the body.
The question is how does interoception help us?
Interoception has a big impact on how we feel, in our busy, stressed-out world we have lost the ability to do this subtle but important body check. We have stopped taking the time to check in with ourselves and see how we feel. By ignoring this hardwired impulse, we are missing an opportunity to feel better.
When you start to become more aware of your body and how it feels you can start to impact your body’s functioning for the better. Everything from decreasing respiration to lowering your pulse to reducing the stress you carry in your body is possible with a higher sense of interoception.
This is what happens during a float session, we become more aware of our breathing and heart rate slowing down. This in turn helps us to greatly reduce stress and anxiety, being more aware of internal processes helps us to understand what our bodies need to feel better.
Interoception can have a huge impact for those suffering with anxiety. Dr Justin Feinstein, one of the leading experts and researchers in floatation therapy from the Laureate Institute of Brain Research has produced research about the benefits of floating and interoception. (1)
In this study it was hypothesised that, ‘By removing exteroceptive sensation, Floatation-REST would enhance awareness for interoceptive sensation.’
It was found that, ‘Floating significantly enhanced attention regulation (ability to sustain attention on body sensations) and self-regulation (ability to regulate distress by attending to body sensations such as the breath).’
It appears that the Float environment seemed to increase the intensity and attention to the interoceptive sensations related to the breath and heartbeat. This is more so than experienced meditators who show poor interoceptive awareness with regards to the cardiac sensation under resting conditions. (2,3)
The study shows how the float environment could help anxious individuals by helping them to anchor their attention onto internal sensations such as breath and heartbeat. This happens as a result of the extreme filtering of all external sensory distractions and stressors, this in turn enhances the interoceptive feeling of the heartbeat and the breath.
We know the float experience minimises visual, auditory, olfactory, gustatory and tactile sensory signals. We also know that during a float session our internal senses such as the vestibular system, proprioceptive system and our interoceptive system are enhanced.
Enhancing the the interoceptive system also aids in effective emotion regulation. Effective emotion regulation involves the ability to accurately detect and evaluate cues related to physiological reactions to stressful events, accompanied by appropriate regulation strategies that temper and influence the emotional response. There is compelling evidence demonstrating links between poor or disrupted awareness of sensory information, or interoceptive awareness, and difficulties with emotion regulation. (4)
Therefore this makes the float tank the perfect tool to increase interoceptive awareness with minimal effort and maximum benefit. Not only are you reducing the amount of tension, slowing your heart rate and breathing you are enhancing what I would argue as being one of the most important systems in your body when dealing with stress, chronic pain or trauma.
Yes, you may be reducing the input into your basic sensory systems but what you gain is a major positive sensory enhancement through interoception. This is why I steer clear of the term sensory deprivation, as it is not a positive term and only focuses on what is taken away and not what you gain.
Next time you float, just listen... You never know what you will learn about yourself.
1. Justin S. Feinstein, Sahib S. Khalsa, Hung Yeh, Obada Al Zoubi, Armen C. Arevian, Colleen Wohlrab, Marie K. Pantino, Laci J. Cartmell, W. Kyle Simmons, Murray B. Stein, and Martin P. Paulus (2018): The Elicitation of Relaxation and Interoceptive Awareness Using Floatation Therapy in Individuals With High Anxiety Sensitivity. Biological Psychiatry 3:555–562
2. Khalsa SS, Rudrauf D, Damasio AR, Davidson RJ, Lutz A, Tranel D (2008): Interoceptive awareness in experienced meditators. Psychophysiology 45:671–677.
3. Khalsa SS, Lapidus RC (2016): Can interoception improve the pragmatic search for biomarkers in psychiatry? Front Psychiatry 7:121
4. Cynthia J. Price, Carole Hooven (2018): Interoceptive Awareness Skills for Emotion Regulation: Theory and Approach of Mindful Awareness in Body-Oriented Therapy (MABT). Frontiers in Psychology 9:798