The Man Who Wasn't There: Investigations into the Strange New Science of the Self (28 page)

“You can’t die, I’ll be alone,” Chris told him. “There won’t be Lewis to my Martin.” Even decades later, as he told me this, Chris’s voice broke; he could not contain his sadness.

David died with family by his bedside holding him. Chris and their father spoke at the funeral, with their father speaking of David’s serious side, while Chris narrated the Martin-and-Lewis stories. And in accordance with David’s wishes that they play “Amazing Grace” at the funeral, a Scottish piper in a kilt played the tune until the service was over.

About two months later, Chris woke up from his sleep. It was early in the morning. He got off the bed, stood up, and walked toward the end of the bed, where there was a dresser. He stretched and turned around and got the fright of his life.

“The shock was electric,” Chris recalled. “Because I was still lying in the bed sleeping, and it was very clearly me lying there sleeping, my first thought was that I had died. I’m dead and this is the first step. I was just gasping. My head was spinning, trying to get a grip on things.”

And then the phone rang.

“I don’t know why, but I picked up the phone and said, ‘Hello.’ It was David. I immediately recognized his voice. I was overwhelmed, but at the same time I had this incredible sensation of joy.” But David didn’t stay on the line for long. “He told me that he didn’t have much time and he just wanted me to know that he was all right, and to tell the rest of the family, then he hung up,” Chris said.

“And then there was this enormous sucking sensation,” said Chris, making a long, drawn-out slurping sound. “I felt like I was dragged, almost thrown, back into the bed, smack into myself.” He woke up screaming. His wife, Sonia, who was asleep next to him, woke up to find a hysterical Chris.

“I was totally freaked out, I was shaking all over, I was sweating, my heart was beating like a racehorse’s,” said Chris.

Chris grew up in a scientific household. His father is a renowned nuclear physicist. Chris’s upbringing was at odds with this experience. “My heart tells me that David was letting me know that he was OK. I really believed at the time that he was somehow communicating with me from beyond death,” Chris said. “But my intellectual side says that’s just silly. But it’s so hard to rationalize; the experience was so real.”

What Chris experienced was a particularly intense doppelgänger effect, also known in neuroscientific jargon as heautoscopy. It is different from an out-of-body experience in many ways.

In an OBE, the self, or center of awareness, gets dissociated from the physical body. The self identifies with a different location in space and has an altered perspective. The physical body itself is usually perceived as lifeless.

In heautoscopy, you perceive an illusory body, and your center of
awareness can shift from within the physical body to the illusory body and back—there’s self-location and self-identification with a volume in space, whether that volume is centered on the physical body or the illusory body. The perspective also shifts accordingly. In Chris’s case, he was situated in his illusory body and then got sucked back into the physical body. But in other cases, such as for Brugger’s young patient, one might experience this shift many times before the hallucination ends.

The other key components of heautoscopy are the presence of intense emotions and the involvement of the sensory-motor system. “Usually, the double is moving and there is interaction, there is sharing of emotions, of thoughts, and that’s what’s giving the impression of a doppelgänger,” said neurologist Lukas Heydrich, who was at the Swiss Federal Institute of Technology in Lausanne when I met him.

To understand the differences in the neural activity associated with (or the neural correlates of) just seeing a visual double while remaining anchored to the physical body versus actually interacting and switching perspectives with a double,
Heydrich and Blanke decided to study patients with brain damage who also experienced these autoscopic phenomena. In 2013, they published the results of the largest such sample to date. The data tell us a lot about the neural correlates of such experiences.

Patients who reported autoscopic hallucinations had lesions in the occipital cortex. Heydrich and Blanke hypothesize that simply seeing a double is not a disturbance of the bodily self, since self-identification, self-location, and first-person perspective remain intact. Rather, the hallucination is the result of the loss of integration between visual and somatosensory signals.

Patients who reported heautoscopic hallucinations, on the other
hand, showed damage to the left posterior insula and adjacent cortical areas. Given that heautoscopic hallucinations involve emotions, it’s revealing that the insular cortex is implicated. We saw how in depersonalization, lowered activity in the insula was correlated with the symptoms of emotional numbness (recall the way tattooed Nicholas back in Nova Scotia felt a lack of emotional vividness). The insula is the hub that integrates visual, auditory, sensory, motor, proprioceptive, and vestibular signals with signals from the viscera. It’s the brain region where the body’s states seem to be represented and the representations are eventually manifested as subjective feelings.

Heydrich and Blanke hypothesize that disturbances in the integration of signals in the insula are leading to the doppelgänger effect. If everything is working as it should, the insular cortex, particularly the anterior part of the insula, is thought to create a subjective feeling of one’s body—a perception that includes emotions and actions. When abnormalities arise in the integration, it’s as if there are now two representations of the body instead of one, and somehow the brain has to choose the representation in which to anchor the self, or rather choose which representation to imbue with self-location, self-identification, and first-person perspective. The hallucination happens when that trinity of parameters defining the basic bodily self switch between different body representations, one of which is not centered in the physical body in terms of geometric coordinates.

Metzinger and Blanke believe that these disturbances of the bodily self are helping them identify the basic attributes you need in order to feel like an embodied self—what they call
the
minimal phenomenal self
. To start with, they argue that the sense of agency is not key to a minimal phenomenal self, since you can create a sense of being a body in some other location by merely passively stroking someone’s
back and messing with their visual input. This requires no agency on the subject’s part. “From a philosopher’s point of view, it is important to find out what is necessary and what is sufficient for self-consciousness,” Metzinger told me. “We have shown that something that most people think is necessary is not necessary, namely agency.”

Rather, the minimal phenomenal self is a more primitive embodied self. Metzinger argues that this feeling of being embodied is a prereflective, prelinguistic form of selfhood—something that comes long before we have the capacity to use the personal pronoun in phrases like “I think.” There’s no narrative here, just the organism having the sense of being a body. The next step in the process is when this primitive selfhood, which is merely an embodiment, turns into selfhood as subjectivity. “If you not only feel that you are in that body, but if you can control your attention, and attend to the body, that’s a stronger form of selfhood,” said Metzinger. “Then you are something that has a perspective, something that is directed at the world, and something that can be directed at itself. That is more than mere embodiment.”

We are now getting close to the heart of the debate over the self. The issue that concerns philosophers and neuroscientists is the subjectivity of the self. Where does that come from? As you can imagine, opinions differ. Blanke, for instance, disagrees with Metzinger’s idea that attention is needed for a strong, subjective selfhood. Blanke thinks that selfhood that arises out of a combination of a sense of body ownership, self-location, and first-person perspective should be independent of attention. We don’t have the empirical data to sort out these nuances. Still, despite these disagreements, there’s excitement that studying autoscopic phenomena will get us closer to understanding the “I,” the self-as-subject, than almost anything else.

Why did this minimal phenomenal self evolve in the first place? Most likely as an adaptation that let the organism orient itself and function better in its environment. If the brain evolved to help the body avoid surprises and remain in homeostatic equilibrium and to effectively move around in its environment, then representing the body in the brain was a necessary step to fine-tune these abilities. Eventually, this representation became conscious, further enabling the organism to be aware of the body’s strengths and weaknesses, which must have given it a survival advantage. But in this case, rather than physical attributes, it was the self that was being honed in evolutionary time.

Saying that the brain models the body doesn’t quite get at the heart of the sense of ownership of the body, or the sense of
mineness.
The brain models things in the environment too, but they don’t have the same feelings attached to them. Take the rubber hand. Once the illusion sets in, you feel as if the rubber hand is yours, but before the illusion, the rubber hand does not have that feel of
mineness
to it. We saw in the chapter on BIID that Metzinger’s phenomenal self model (PSM) offers one kind of “representationalist” explanation. If the rubber hand is in the world-model constructed by the brain, it does not have a feeling of
mineness
, but if it’s incorporated into the PSM, it becomes mine.

There are mechanistic explanations for the feeling of
mineness
. We saw hints of this in exploring schizophrenia. The feeling of agency—that
I
am the initiator of my actions, or a feeling of
mineness
to one’s actions—may be the outcome of the brain being able to predict the consequences of one’s motor actions correctly. If something goes wrong either in the prediction phase, when the prediction is
being compared to the actual outcome of the action, or for that matter anywhere in that pathway, then an action may not have the feeling of being self-initiated. And so it’s implicitly attributed to an external agent—to non-self.

Could the feelings of body ownership arise due to similar mechanisms? Philosopher Jakob Hohwy has argued that
the phenomenon of
mineness
in general—whether for actions or perceptions—can be the outcome of a predictive brain. So, in this way of thinking, the brain is using its internal models to predict the causes for various sensory signals, and the brain’s job is to minimize prediction errors. So, just like a sense of agency results from successful predictions, a sense of body ownership would also result from minimal prediction errors for the body as a whole.

Given all the talk of the minimal self and the extended narrative self, it’s easy to get misled into imagining the self as an onion that can be peeled layer by layer, or as an orange that can be segmented. Yes, it’s true that our narrative self has, in an evolutionary-biology sense, evolved after the bodily or minimal self, but in the complex selves that we are today, modern neuroscience is clearly telling us that the bodily self informs the narrative and your narrative can change how your body feels, and both the bodily self and one’s narrative are influenced by one’s cultural context. In this emerging understanding, brain, body, mind, self, and society are inseparable, insofar as a functioning human being is concerned.