The embodied self

Among those in transhumanism who seek eternal life, there are projects that prioritize, for example, transplanting the human brain into a robotic body or preserving the body through cryogenics. At companies like Alcor Cryonics, clients can preserve just their head or their entire body in the hope that, in the future, we will have enough technology to "revive" these people. But would it be enough to preserve just the head, or is the whole body necessary for us to perceive the world?

A recentarticle written by University of Sussex neuroscience and psychiatry professor Sarah Garfinkel indicates that, in fact, it seems that mind and body communicate so that the individual (if they even exist at all, as some of her professional colleagues and also Buddhists question) perceives the external world.

To illustrate her explanation, Garfinkel gives the example of when someone suddenly speaks to us when we think we are alone. Even if they apologize for the scare, our heart keeps racing in our chest, so what is this relationship between our brain and our heart? According to the neuroscientist, we are accustomed to thinking that our senses are limited to five—smell, taste, touch, sight, and hearing—but these are classified as exteroceptive senses, meaning they only concern what we feel outside our body. Interoceptive senses, on the other hand, inform us about the sensations we have inside our body, such as our heartbeat, the feeling of butterflies in our stomach, or even the sensation of hunger.

“The brain represents, integrates, and prioritizes interoceptive information from inside the body. This is communicated through a series of neural and humoral connections (for example, through the blood). This sensing of the body’s internal states is part of the exchange between the body and the brain: it maintains homeostasis, the physiological stability necessary for survival; it provides the necessary motivational drives like hunger and thirst; it explicitly represents bodily sensations, such as bladder distension. But that’s not all, and that is the beauty of interoception: our feelings, thoughts, and perceptions are also influenced by this dynamic interaction between the body and the brain.”

But this is not, in fact, a new claim. Since 1862, American philosopher William James argued that the mental aspects of emotions, that is, the “feeling states,” were a product of physiology. James proposed a logic that reversed how we intuitively think about causality by suggesting that the physiological changes in our body, in themselves, gave rise to an emotional state: our heart, therefore, does not race because we are afraid; fear, in reality, arises because our heart is racing. According to Garfinkel, more recent experiments also demonstrate that neural and mental representations of our internal bodily sensations are important for our experience of emotions, and consequently, those who have greater interoception tend to experience emotions with more intensity. In other words, in the neuroscientist’s words:

“The anterior insula brain region is of extreme importance in processing both emotions and internal visceral signals, which supports the idea that this area is also important in processing internal bodily sensations as a means of informing emotional experience. Individuals with greater interoception also have greater insula activation during interoceptive processing and a higher density of gray matter in this area.”

But what you must be wondering now is whether you have this sharper interoception or not, and what that, after all, means. According to Garfinkel, some people have a better perception of what happens inside their bodies. While most of us only feel our heart when it races because we are startled or running to catch a bus, not everyone can actually feel their own heart while at rest. This precision can be verified in a laboratory, as experts monitor physiological signals and measure the accuracy with which they can be detected. Historically, this type of research has focused on the heart, as its signals can be better quantified through external stimuli, such as when we can perceive our heartbeat in our ears. As participants indicate the rhythm of this perception, experts can better quantify how precise the individual’s sensation is.

On the other hand, Garfinkel says it is also possible to measure subjective indices of how accurate people think they are when trying to perceive their bodily sensations. For this, some questionnaires and personal accounts are used so that experts can cross-reference what they perceive with what is actually occurring in their bodies. Beyond that, there is also the methodology that uses brain imaging scanning methods, such as functional neuroimaging, which is used to investigate which areas of the brain are more active when focusing on an interoceptive signal (like the heart) compared to an exteroceptive signal (auditory beats).

However, some individuals may have this type of perception not only limited but also impaired by conditions such as Alexithymia, which is defined as a deficiency in the ability to detect and identify emotions, and which is associated with lower precision of interoceptive sensations. Autistic individuals, who may have difficulty understanding emotions, have also been shown to have this type of problem with their interoceptive perception. The same can also occur in those who have borderline personality disorder. What Garfinkel notes, however, is that interventions designed to regain focus on the body, such as the practice of mindfulness, have not only shown improvement in cases of anxiety but can also be a way to facilitate access to this perception.

Finally, in a similar way, Garfinkel comments on how our body also changes when perceiving the emotions of those we love—that is, empathy can become something physical as our heart may race when we see that a loved one is afraid, or our pupils may dilate when we realize someone is sad. “If you pay attention to your heart and bodily responses, they can tell you how you are feeling and allow you to share that in the emotion of others. Interoception can improve the depth of our own emotions, emotionally connect those around us, and guide our intuitive instincts. We are only now learning how what we think and feel is shaped by this dynamic interaction between the body and the brain,” the neuroscientist concludes.

Thus, when the transhumanist movement in the 80s and 90s was driven by the idea of the mind over the body (giving rise to works like Hans Moravec’s Mind Children and science fiction like Ghost in the Shell, Neuromancer, and Altered Carbon), perhaps it did not take into account the important body-brain relationship that enables the complexity of perceptions, emotions, and sensations we have when capturing both the outer world and the inner world. If, in the future, it is indeed possible to bring back to life those people who had their bodies preserved, will they really be able to enjoy the same capacities and sensory experiences as before, or will some of their perceptions be deprived, and therefore, stripped of some of the layers that make up a supposed "self"?

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