ALTERED STATES: Sensory Deprivation and the Mind

ALTERED STATES: Sensory Deprivation and the Mind

Imagine a state of mind in total sensory deprivation: floating in a void abandoned by sound, absent of all light, and devoid of gravity. In this void there is no sense of up and down, left or right; the perceivable contrast between the you-internal and the world-external has faded away. In this void you are simply a plane of being—the “I” who thinks, nothing and everything all at once.

Those who have attempted to achieve similar states of mind through meditation, trance, or sleep may have discovered declaring total independence from the external reality is an incredibly laborious task. The strain to concentrate on nothing can become a feedback loop in which one feels “stuck” in one’s own mind. For most people it is virtually impossible to conceive of consciousness absent the demands of the external reality.

Sensory Deprivation tank image

Inside a sensory deprivation tank in Denver, COSource: Zimmerman

In 1954, neurologist and psychoanalyst John C. Lilly conceived of an environment that could achieve exactly that: full sensory deprivation. With further experimentation through the 60s and 70s, advocacy in literature, the Hollywood film Altered States, The Joe Rogan Experience, and J.J. Abram’s Fringe, the once-esoteric practice of sensory deprivation has become readily available. Floatation centers can now be found across nearly half of the United States.

So what exactly happens to the mind during this particular state? According to John C. Lilly’s final summary report to the National Institute of Mental Health, entitled “Programming and Metaprogramming in the Human Biocomputer,” the internal mental process goes theoretically like this:1

Initially, the absence of external sensory stimulation of the brain creates a vacuum into which the mind begins to seek out internal sources of stimulation (physical and/or mental). The pulsing sounds of blood flowing through the body and the rhythmic, oceanic sound of breathing can become inexorably loud. Additionally, projections of negative space—delineating the absence of an external reality—can also begin to dominate conscious awareness.

For some these internal projections can become too oppressive. Given enough time, however, most subjects pass through this state to the more desirable sensation of the inner mind entirely taking over where sensory perception has subsided. The mind experiences an outward expansion beyond the physical self—physicality becomes irrelevant and consciousness becomes the only apparent reality.

fMRI scan image

fMRI scan of distinct brain modules including visual (yellow), sensory/motor (orange), basal ganglia (red) cortices as well as the default/rest mode (blue/green)
Source: PLoS One. 2012; 7(8) e44428; August 28, 2012

The experience is akin to stepping back into the womb, and the altered state of mind one discovers has to do with the competitive nature of  brain processing. To hold and display the accepted view of reality in all its detail demands a great deal of attention from the brain and a careful balance is achieved between processing sensory information, motor control of the body, and cognition and feeling. The fraction of mind dedicated to any one mental process can be expanded or contracted with respect to certain parameters.

In extreme sensory situations (such as the experience of a car accident) the brain is working overtime to process all the extra information and less attention is given to motor control and cognition awareness. The opposite is true in states requiring extreme motor initiation (such as running a marathon) whereby sensory processing and cognition is diminished.

In a sensory deprivation environment the demands of sensory information as well as required attention to motor activity are maximally attenuated and the greatest possible attention is given over to cognition and emotion.

According to the literature the interpretation of this unique state of mind is largely subjective to one’s internal paradigm as well as the psychological state of the individual. Given the potential exposure of previously sheltered aspects of the self-mind to consciousness the emotional impact can vary greatly between extreme fear and absolute elation.

Frankly, one is introduced to a completely naked self. The internal mind, with all of its biases and filters, is now entirely perceivable and is able to think and feel in whatever context it sees fit. Users report experiencing extreme states of mental relaxation and clarity, enhanced learning capacities, excited motivation and creativity, deeper insight into unconscious emotional and cognitive layers, increased post-float athletic performance, and improved injury recovery time.

sensory deprivation tank image

One example of a sensory deprivation tank in Denver, CO
Source: Zimmerman

So how exactly does a sensory deprivation tank work?

A typical tank resembles a large escape-pod; a series of pumps and temperature gauges on one end regulate salinity, temperature, and sanitation. On the other end is a sound-and-light-proof door. Inside is a saturated solution of Epsom salts (MgSO4- 7H2O) at a solution density of 1.30 grams per cubic centimeter, kept at around ninety-five degrees Fahrenheit. The salinity and temperature are such that one can float supine on the water’s surface and (while motionless) not feel the water at all. The sensation of floating also relieves the body of the sensation of gravity.

The result of sensory deprivation is an altered state of consciousness that most closely resembles deep meditation. Some might call it Nirvana while some might call it Hell; what one gains to learn from the experience is entirely open-ended and potentially mutable. What you go in with becomes a part of the experience, what you come out with becomes a part of who you are.

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1. Lilly, John C. Programming and Metaprogramming in the Human Biocomputer. 2nd ed. Portland, OR: Coincidence Control, 2014. Print. (Amazon Link

Posted by Zimmerman

This is one in a series of articles on altered states.

The Adaptable Mind is an issue of Next Culture focused on the mind’s ability to adapt to what’s new.