Explained! Sensory Deprivation Tank Benefits, Effects and Experience

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What is Sensory Deprivation

Sensory deprivation is the technique by which sensory stimuli is deliberately reduced or removed. This can be all or any of the sensory stimuli (sight, sound, touch, etc.). 

Sensory deprivation is the concept behind isolation tanks or floatation tanks, which are used for a therapy commonly referred to as Restricted Environmental Stimulation Therapy (REST) where sound and light (sensory) stimuli are completely eliminated. 

What is a Float Tank?

Float tanks are the containers or chambers used for sensory deprivation or REST therapy. They contain water that is mixed with a large quantity of Epsom salt and up to 1 foot deep or more.

It is an enclosed container that has a door that shuts out any form of light. The subject or person undergoing REST therapy lies down and floats on the water in sensory isolation.

Types of Float Tanks and Dimensions

The tanks are typically made in different sizes and are available as pods, tanks and cabins. 

Float Pods: The pods are the smaller size tanks which may just be enough for one person and usually a little bigger than an average body size. The measurement of most pods is around 7 feet long and 4 feet wide. It also has a hooded cover that can be closed slightly or completely depending on your comfort level. People who are disposed to feel claustrophobic may be more likely to experience it in a pod.  

Float Cabins: Some people call these tanks as well. They are bigger than the pods and can be more spacious than the pod. Most float tanks are 8 feet long and 4-5 feet wide. Float cabins come in a variety of shapes, sizes and designs and not just a rectangular six-sided box as most people think. 

Float Rooms: These are not enclosed like a tank or pod but are open like standard rooms with high ceilings. Most of the rooms are up to 8 feet long and can be between 4-6 feet wide and some are designed to take up to two or three people at the same time. 

Most of the recent float tanks are fitted with different accessories like LED lights, music speakers etc., and controls for these accessories.  

How Sensory Deprivation and Floatation Therapy works

Floatation therapy largely comprises of float relaxation and sensory deprivation. So you don’t need to worry about how you can float even if you don’t know how to swim. First of all, you don’t need to know how to swim before you can undergo a floatation tank session and there is no risk of drowning in a float tank. 

This is because the water in the tank is too shallow (maximum a little more than 1 foot deep) for anybody to drown in it. People are able to float because the water is mixed with large quantities of salt (Epsom Salt).

Objects typically float better on salty water than fresh water because the salt makes the water to be very dense. The water in floatation tanks is mixed with large quantities of salt which makes it very dense enough to suspend the body. 

The other side of sensory deprivation is achieved with the design of the float tanks. The tanks are designed in a manner such that both sight and sound stimuli are eliminated completely.

When you step into the tank and lie down, you float almost immediately and light and sound is cut off completely. The water is also heated to the same temperature as the body temperature which makes it difficult to feel or have active sensory stimuli. 

However, some floatation tanks have speakers and you can choose to keep the music playing if you prefer that. 

Effects of Sensory Deprivation

There are several direct results of sensory deprivation on the body which can translate into different physiologic changes. Some of these effects were demonstrated when John Dickerson (former CBS This Morning Host) decided to go for a floatation session.  

He shared his results publicly on the national morning show in a piece titled “Pay Attention, How sensory deprivation and floating impact the mind”. His brain and cardiac activity measurements were taken using devices and methods created by a Neurophysiologist that worked with him on this project. 

 The results showed that his heart rate dropped significantly soon after entering the tank which was followed by a significant drop in blood pressure as well as his breathing or respiratory rate slowing down significantly too.  

All of these are indicative of diminishing or eliminated sensory stimuli that are important in preparing the body for “fight or flee” response usually activated by the sympathetic nervous system.

The drop in heart rate, blood pressure, and respiratory rate are also indicative of the effects of the parasympathetic nervous system which works to calm you down when there is no sense of danger or need for action.   

Sensory deprivation used in REST therapy usually results in the following effects:

Lower Cortisol Level: Cortisol is a stress hormone that is released when the body senses a dangerous situation or any active situation. When sensory stimuli are eliminated during REST therapy, cortisol secretion decreases because it is not needed.

Lower Blood Pressure and Heart Rate: The absence of cortisol which activates the sensory system for fight and response causes the parasympathetic nervous system to be activated. The parasympathetic system tends to slow down the body and balance out the effects of the sensory nervous system. This is evident in the drop in blood pressure, and slower heart rate.

Increased Secretion of Calming Neurotransmitters: Sensory deprivation is likely to have the same effect on the brain and cause calming neurotransmitters to be selected. This is responsible for the calming effect and an increased sense of relaxation.

Benefits of Sensory Deprivation Float Tanks

sensory deprivation - float tank experience

There are several reported benefits of float tanks by many people who have had the experience of a floatation session. Perhaps the best way to demonstrate the benefit of restricted environmental stimulation therapy (REST) using a floatation tank is to discuss the results of scientific research that studied that.

Research that studied a group of fifty different people (most of them with the diagnosis of Post Traumatic Stress Disorder (PTSD), Generalized Anxiety Disorder (GAD) and Chronic Pain) to find out what they benefited from the floatation session. 

Several benefits were reported by the participants but the most significantly reported benefits of this process include: 

  • Reduced Pain: There are other research studies that showed a significant decrease in chronic pain after using a floatation tank. 
  • Reduced Depression: This may be why REST therapy is said to be effective in treating addiction
  • Reduced Fatigue: Most people who have done it usually report feeling reinvigorated 
  • Reduced Stress: Most people also reported a decreased sense of fatigue after completing the floatation sessions.
  • Reduced Muscle Tension: Another research also demonstrated similar results of reduced chronic pain after undergoing a floatation tank session. 
  • Reduce Sense or Feeling of Anxiety: There is available research evidence to corroborate this find that REST can significantly reduce anxiety disorders. 

Other reported benefits of sensory deprivation in a floatation tank from the above-mentioned study indicated that study participants experienced an increased sense of relaxation, peace, happiness, energy, high positive affect, as well as increased sexual desire.

Negative Side Effects of Float Tanks

The study participants in the research also mentioned specific side-effects that they did not like. Some of the side-effects were mild while some of them were very significant. Some of the significant side-effects in decreasing order of significance or magnitude include:

1. Itchiness: Most people reported this side effect which could be a direct result of the salt content in the water. (You need to check if your skin is sensitive to Epsom Salt)

2. Dry Mouth: A lot of the study participants also reported having a dry mouth which was a discomfort. This can also be the result of salt content in the water

3. Paranoia: Fewer people reported having this feeling. Normally, people who are scared of closed places or enclosures (Claustrophobic) may have this feeling when they are in the tank.

4. Anxiety or Panic: Fewer people also reported this. This may be related to the fear of closed places.

5. Stomach Discomfort: Fewer people reported having this feeling

6. Headache or Dizziness: Few people reported having headaches

7. Nausea: This was reported by very few people

8. Diarrhea: Very few people reported having diarrhea after the session

Some of the side-effects were reported by very few people and this may just be individual differences (variation). Hence, it may be inappropriate to generalize these of side-effects. One thing that was clear is that no serious or debilitating side effects were observed.

How to Prepare for Float Tank Sessions

It is important that you go for your floatation session prepared if you want to get the best results out of it. Almost all float tank spas have everything you need so you don’t have to think about what to bring with you.

You should be given hair care products (conditioner, hand hairdryer etc.)  and body care products to freshen up after your session. However, you can bring your body products if you don’t want to use the ones provided for you. 

Also, there are a couple of things that you need to do prior to your session so that you can get the best experience out of it. These include:

Discontinue any drug, alcohol,  substance or medication that may have a sedative effect before your floatation tank session. This will prevent the risk of falling asleep during your session which could lead to a drowning hazard (very unlikely since the water is shallow).

  • Always plan your sessions and allow for extra time to relax and freshen up after your session (at least 90 minutes for a 60 minutes session). 
  • Limit or stop caffeine intake before your session. Caffeine or coffee are stimulants and may interfere with your ability to relax. 
  • If you have any  health issues especially seizures, heart, and cardiovascular problems, you may need to provider a report from your health provider that it is okay for you to use a float tank
  • Make sure you do not have any communicable disease shortly before or during the time you want to use a float tank. 
  • Eat before going for your session but don’t overfeed to prevent the discomfort of hunger or full stomach (if you overfeed)  when you are in the tank. 
  • Avoid foods that can cause flatulence (lentils, beans etc.) 
  • Avoid shaving on the day of your float session. This is because the water in the tank will exacerbate your pain if you get a cut when shaving. This will disrupt your sense of feeling since the therapy is based on cutting off any sensory stimuli
  • If you have colored your hair, flush it at least four times to remove the hair color before entering the tank. 
  • Also, don’t forget to have a shower after your session, this will help you to wash off the salty water from your body since this may cause body itching. 
  • Remember you can ask the spa office for their safety and sanitation guidelines, inspection results and permits from the local city health department. You have a right to know and the spa office can show you that information if you want.

What to wear for Sensory Deprivation Float Tanks

Most people prefer to float without any clothes on (even underwear). This is because they are in the room or tank by themselves, and nobody will see them. Also, most people recommend this style because they think that your clothes (underwear) may become a distraction since you are trying to eliminate any stimuli. However, you are free to wear what is most suitable and comfortable for you and some people prefer to wear a swimsuit or just panties.

Also, you don’t have to cover your hair as this may distract you too, except if you don’t want your hair to get wet then you can cover it with a shower cap. 

General Safety of Sensory Deprivation Float Tanks 

There are standards that float spas are required to keep and maintain every day. Adherence to these standard guidelines is necessary for business permits in most cities and permits can be revoked or cancelled if these standards are not kept accordingly.  

You can visit this link to see the current float tank standards in North America. 

Frequency of Float Tank Therapy

There is no specific recommended frequency for float tank use. You can use it every day, weekly, or monthly depending on your needs. However, doing it continuously at regular intervals may be helpful in maintaining the benefits from float tank sessions. 

What to Do After Float Tank Sessions

You can go about your business after a float tank session. However, the first few hours may just be a good time to relax, think and concentrate on your thoughts or ideas. Maybe this is also the best time for you to unleash your creative powers as a result of some of the derived benefits from float tank use. 

Sanitary Hygiene and Care of Float Tanks

Sanitary standards are very important in using float tanks. While it is very possible to float when having certain conditions that may affect the sanitation of the tanks (like during your menstrual period), it is best to discuss specific concerns with your local float spa provider and they will let you know the appropriate thing to do. This is because guidelines may vary and individual conditions too. So contact your local float tank provider to help you with your concerns.