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

Descartes’s dualism is passé. No one is arguing for a self that has an independent ontological reality, something that could exist even after the brain and body are gone. No one’s arguing either for a single privileged place in the brain as the sole custodian of the self. Yes, there are some brain regions that are more important than others for our sense of self—such as the insular cortex, the temporoparietal junction, and the medial prefrontal cortex—but none that can be said to be the singular domain of the self. There’s also little argument that our narrative self is a fiction—a story without a storyteller. In fact, anything that can constitute the self-as-object—including the sense of body ownership—can be argued as being constructed, sans a constructor. Instead of Cartesian dualism, which relegated the body to the status of a mere vessel, we now have a picture of the sense of self as the outcome of neural processes that are tightly integrated with the body—processes that combine brain, body, mind, and even culture to make us who we are. What remains to be satisfactorily explained is the self-as-subject or self-as-knower, and that’s where the differences arise.

It’s also unrealistic to expect a person with Alzheimer’s to cope with the loss of the narrative self by focusing on the fact that there is no narrator to begin with.

As we have already seen, the brain takes care of the body by maintaining homeostasis, which involves keeping the body’s physiology at an optimal state despite wide variations in the external environment.

On one hand, it can lead to chronic anxiety or neuroticism. In 2006, Martin Paulus and Murray Stein argued that chronic anxiety is the result of a malfunctioning anterior insula, as it constantly generates higher than normal prediction errors. Picard posits that the opposite may be happening in ecstatic seizures. The electrical storm in the anterior insula may be disrupting the mechanism, resulting in few or no prediction errors. As a result, the person is left feeling as if nothing is wrong with the world, that everything makes sense, generating a feeling of absolute certainty.

“The out-of-body-created memories were significantly less structured in terms of temporal and spatial order of events, and less vivid,” Ehrsson told me in an email.

Aspects of the self that seemingly give us both synchronic and diachronic unity—our narrative, our sense of being agents of our actions and initiators of our thoughts, our sense of ownership of body parts, our sense that we are our emotions, our sense of being located in a volume of space that is our body and possessing a geometric perspective that originates behind our eyes—all of these can be argued as comprising the self-as-object. These properties can be thought of as constructed. The question is whether there is a constructor—or merely the appearance of a constructor.

Dennett says the self “is the same kind of thing as a center of gravity [in physics], an abstraction that is, in spite of its abstractness, tightly coupled to the physical world.” Any physical system has a center of gravity—but it’s not a thing, but a property of the system. There is no one atom or molecule that makes up the center of gravity; nonetheless this mathematical abstraction has real consequences. The self, says Dennett, is the center of narrative gravity: a “fiction, posited in order to unify and make sense of an otherwise bafflingly complex collection of actions, utterances, fidgets, complaints, promises, and so forth, that make up a person.”

Seen from the perspective of Craig’s results, the posterior insula is representing the actual temperature of the water, but depending on whether you drink the water on a hot day or an icy-cold day, your subjective feelings about the glass of water will differ—possibly from an extremely pleasant sensation to something that is undesirable. This subjective feeling is what’s being represented in the anterior insula.

In Craig’s model, the anterior insula integrates interoceptive, exteroceptive, and the body’s state of action to create a “global emotional moment” once every 125 milliseconds. It’s these global emotional moments strung together that give us a continuous sense of self, even though the moments themselves are discrete, he argues. It’s like watching a movie—even though the cinema screen is displaying twenty-four discrete frames per second, we perceive a seamless continuum. A hyperactive anterior insula could potentially generate these global emotional moments faster and faster, leading to a subjective sense of time dilation.

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.