Introduction
David Eagleman’s (2015) book entitled The Brain details scientific discoveries about the way the human brain processes information. The book details the ways in which one’s sensory capabilities and sensory processing activities formulates the way in which one interprets the external environment. It is the combination of sensory capabilities and the processing of sensory input that is largely responsible for the “reality” that one experiences (Eagleman, 2015). The external environment or what humanity would collectively call “reality” is not necessarily what truly exists. Reality may in fact be more subjective or internal than previously thought. Therefore, one would expect that individuals with different types of inherent sensory processing sensitivities would experience a quite different reality than those without those sensitivities.
A biological trait discovered and researched by Elaine Aron (1996), called high sensitivity or sensory processing sensitivity, theoretically causes those with the trait to experience the external environment (e.g. “reality”) vastly different from those who do not possess the trait. In addition, those individuals who have sustained mild traumatic brain injuries can experience shifts in the way they process sensory input (Keatley & Whittemore, 2010). Individuals with the trait of high sensitivity and sustained mild traumatic brain injuries are only two examples of how the human brain can be capable of processing sensory input in different ways. Yet, it is the underlying sensory processing capabilities enabled by the brain’s chemistry that determines what an individual experiences as real.
How Sensory Processing Capabilities Shape Reality
Eagleman (2015) states that an individual’s “sensory experiences are taking place in storms of activity within the computational material” of the brain (p. 39). The author goes on to explain that the brain itself is not capable of gaining access to the external environment, but that the body’s sensory organs (e.g. eyes, nose, ears, skin, mouth) are the ones that gather and interpret information from the external environment (Eagleman, 2015). In other words, the brain learns to shape reality based on information from the sensory organs (Eagleman, 2015). Scientific studies have revealed that blind individuals who have their vision capabilities restored have problems with “seeing” the external environment in the same way that those have had vision capabilities from an early age (Eagleman, 2015). What these studies suggest is that depending upon one’s physical sensory capabilities, one’s brain then trains itself on what is “real” and what is not “real.”
Studies of sensory deprivation in individuals have revealed that the brain continues to construct its own internal sense of reality, even when there is a lack of sensory input (Eagleman, 2015). This phenomena occurs, in theory, because the brain is already trained to “see,” “hear,” “sense,” or “taste” certain components of the external environment. Even without sensory input, the brain already has a set of expectations or an internal sense of reality that continues to play out regardless of what actually exists externally (Eagleman, 2015). Still, despite this phenomenon the brain must have some sense of predetermined reality in order to produce that reality – whether it is in the form of hallucinations or dreams. One could argue that individuals who claim to have extrasensory perception capabilities are experiencing a unique internal reality that is not dependent on the real-time physical existence of what they are experiencing. Perhaps the invisible reality they are experiencing is based on a combination of physical information their sensory organs have processed in the past and what the brain has internalized as real. In other words, extrasensory perception is an ability to synthesize the experience of one’s current sensory input and one’s collection of previous sensory input.
High Sensitivity
Somewhat related to the idea (and sometimes intertwined) of extrasensory perception is the notion of the trait of sensory processing sensitivity. In the 1990s, Elaine Aron (1996) conducted groundbreaking research on the idea that fifteen to twenty percent of all species possess the trait of sensory processing sensitivity or high sensitivity. Based on her research, Aron (1996) concluded that the trait is biological and consists of the following hallmarks in humans: a rich inner life, being more aware of subtleties in the environment, being keenly aware of others’ moods and feelings (often unspoken), becoming easily overwhelmed in environments with high amounts of sensory input (e.g. crowds, loud noises), and being deeply moved by emotions or objects (e.g. works of art) that contain emotion. As part of her research, Aron (1996) acknowledged that the brain contains two separate systems and that the degree of balance between these two systems is responsible for high sensitivity. Those two systems include the part of the brain that takes in information from sensory organs and propel individuals to take action. The other system is the part of the brain that inhibits individuals from taking action based on the same sensory input (Aron, 1996). Those who possess the trait of high sensitivity tend to favor the brain’s latter system – that of a high degree of internal processing without necessarily a large amount of external activity in response to that processing (Aron, 1996).
While Aron (1996) believes that the occurrence and development of high sensitivity is primarily biological (e.g. inherited through one’s DNA), she does acknowledge that the trait can be enhanced or subdued through environmental conditioning or experience. That is if an individual experiences a high degree of negative sensory input in the form of abuse or traumatic experiences, the system within the brain that tends to favor inhibition can become dominant (Aron, 1996). The individual has learned that action based on input from the sensory organs leads to harmful consequences and inaction leads to protection from those same consequences. In the case of post-traumatic stress disorder, the individual’s experience of the external environment becomes one of fear and enhanced awareness to the sensory input that correlated with the traumatic experience (Aron, 1996). This does not mean that the trait of high sensitivity is equated with trauma or post-traumatic stress disorder, but that the trait is interrelated in the sense that that the sensitivity one’s brain develops as a result of trauma is an enhanced version of high sensitivity.
Those who inherit the trait of high sensitivity are thought to have a more sensitive nervous system – that is the individual’s sensory organs are more receptive to sensory input. This means that sensory input is processed as being stronger than the individual who does not have as sensitive of a nervous system (Aron, 1996). Therefore, a noise from a car’s engine can be processed as being louder and a major source of irritation by the highly sensitive individual and a mere background occurrence by the non-sensitive person. In addition, due to the sensitive individual’s depth of internal processing, he or she is more likely to experience vivid dreams over the non-sensitive individual (Aron, 1996). The famed psychologist, Carl Jung thought that individuals who have tendency to have a rich inner life might experience a prophetic or psychic reality (Aron, 1996). According to Jung, these individuals have an internal connection to the collective unconscious and the ability to synthesize patterns in ways that individuals more attuned to their external environments do not (Aron, 1996). This suggests that individuals with a tendency to favor the brain’s processing system of non-action or observation experience a different reality than those whose brains favor the system of external action. Perhaps a reality that is in part based on the sensory inputs of more than the individual, but of multiple individuals. That is to say, individuals with more sensitive sensory organs may experience and therefore process experiences outside of their own.
Mild Traumatic Brain Injury
Mild traumatic brain injury – commonly known as a concussion – has been shown to cause a myriad of short-term and long-term alternations in the brain’s chemistry. Those changes in the brain’s chemistry make survivors more likely to experience depression, anxiety, and post-traumatic stress disorder (Keatley & Whittemore, 2010). Similar to individuals with the trait of high sensitivity, the brains of those who have sustained a concussion become more sensitive to sensory stimulation. In fact, Keatley & Whittemore (2010) openly state that “heightened sensitivity to the environment is a common symptom of mild traumatic brain injury” (pg. 15). Besides a vulnerability to post-traumatic stress disorder, anxiety and depression, mild traumatic brain injury can results in a number of symptoms that span the physical, emotional and cognitive realms.
Physical symptoms include vertigo, nausea, balance problems, low energy, blurred vision, and sensitivity to lights and sounds. Emotional symptoms can include mood swings, apathy, problems containing anger, nightmares, and feeling easily overwhelmed. Cognitive symptoms span from the inability to recall words, the inability to focus, short-term memory loss, the inability to process information in noisy environments, and brain fatigue (Keatley & Whittemore, 2010). These symptoms reveal the existence of an alternative reality to those individuals who have not sustained a mild traumatic brain injury. The task of reading a book can be more strenuous as the brain experiences increased stimulation not only from the words, but from the images and associations that the words are creating within the brain. The non-concussed individual is able to internally process the same amount of stimulation in less amount of time, and possibly construct a different set of images within his or her mind. Further complicating matters is that medical science is now aware that brain injuries and their aftermaths are unique (Keatley & Whittemore, 2010). This means that each individual that sustains a mild traumatic brain injury can and does experience a different set of symptoms, experiences those symptoms for periods of time, and experiences different long-term outcomes.
Essentially, one survivor’s reality not only becomes altered from his or her previous reality, but is not necessarily identical with the reality of another survivor’s. Although similarities can exist between the realities of survivors, one may become permanently sensitive to noise and continue to experience vertigo for the rest of his or her life. Another survivor may find that his or her personality has regressed to the predilections of his or her younger self, or even a self that he or she does not recognize. What is known is that a concussion alters the brain’s chemistry and the way it processes sensory input (Keatley & Whittemore, 2010). The way the individual saw the world before is no longer congruent with the way that he or she is able to see the world now. It is not necessarily the environment or sensory input that has changed, but the processing of it by the brain’s neurons.
Conclusion
Reality is a subjective, internal experience that stems from the brain’s processing of sensory input. Sensitivity to sensory input, either by biological traits, accumulation of traumatic experiences, and/or physical injuries to the brain, can result in the formation of unique realities. This does not suggest that those unique realities are necessarily equivalent to delusions or mental illness, but that those realities differ from the realities of those who do not process information in the same way. Sensitivity to sensory input can be the result of a more finely tuned nervous system, which the brain controls. The question is whether various brain chemistries cause these sensitivities or whether other physical and environmental differences result in a brain that adapts to those differences with depth of processing. A combination of these interdependent occurrences is the most likely explanation.
References
Aron, Elaine N. (1996). The Highly Sensitive Person. New York: Broadway Books.
Eagleman, David (2015). The Brain. New York: Pantheon Books.
Keatley, Mary Ann & Whittemore, Laura L. (2010). Understanding Mild Traumatic Brain
Injury. Boulder, CO: Brain Injury Hope Foundation.
