Last time, I tried to explain how the world of objects in space and time isn’t the world of particles and waves.
This was disconcerting, but it gets worse when we consider our own identities. According to two popular ways of looking at identity, at self — the notion that, no matter how surreal the universe becomes, I’m “in here” perceiving and acting on it — is not really real, either.
One of these ways of looking at consciousness is proposed by Daniel Dennett in his book Consciousness Explained. Dennett describes consciousness mechanically, as the result of the mental processes by which the brain constantly organizes the perceptual inputs which are its source of information. He calls this group of processes the “Multiple Drafts” model of consciousness:
According to the Multiple Drafts model, all varieties of perception — indeed, all varieties of thought or mental activity — are accomplished in the brain by parallel, multitrack processes of interpretation and elaboration of sensory inputs. Information entering the nervous system is under continuous “editorial revision.”
Dennett proposes a concurrent series of processes, brain actions which blend and interact dynamically, hence the idea that rather than a single “narrative” there is a group of drafts whose threads the brain can combine in a wide variety of ways:
This stream of contents is only rather like a narrative because of its multiplicity; at any point in time there are multiple “drafts” of narrative fragments at various stages of editing in various places in the brain.
Why is there no single narrative, no “stream of consciousness”? Because, Dennett argues, there is no whole identity, no central observer, which weaves our multiple drafts into a single, coherent story:
There are multiple channels in which specialist circuits try, in parallel pandemoniums, to do their various things, creating Multiple Drafts as they go. Most of these fragmentary drafts of “narrative” play short-lived roles in the modulation of current activity but some get promoted to further functional roles, in swift succession, by the activity of a virtual machine in the brain.
According to Dennett, this set of processes is not “hard-wired.” Rather, it is an adaptation of mental processes which began with other functions:
They were not developed to perform peculiarly human actions, such as reading and writing, but ducking, predator-avoiding, face recognizing, grasping, throwing, berry-picking, and other essential tasks. They are often oppor-tunistically enlisted in new roles, for which their native talents more or less suit them.
Innate mental processes, shared to greater or less extent with other animals, work in conjunction with uniquely human factors:
… it is augmented, and sometimes even overwhelmed in importance, by microhabits of thought that are developed in the individual, partly idiosyncratic results of self-exploration and partly the predesigned gifts of culture. Thousands of memes, mostly borne by language, but also by wordless “images” and other data structures, take up residence in an individual brain.
In this conception of consciousness, there is no Cartesian self, no non-material soul, no single “I” to take its place in “I think, therefore I am.” Our identities are closer to “my brain does stuff, and we are they.” This ruthlessly mechanistic view of consciousness, of identity, of self, removes the soul, Rile’s “ghost in the machine,” and replaces it with an organic computer, a biological Von Neumann machine.
Related to this idea, but somewhat differing from it, is the notion that “we are our narratives.” Combining physiological data and psychological insights, the narratives explanation of consciousness is another way of denying the reality of a separate, single self. In this view, the left cerebral cortex works to organize our sensory input and experiences into a fluid autobiography, one with all of the key features we recognize in the creative fictions of storytellers.
John Bickle and Sean Keating (url below) put it this way:
“We are our narratives” has become a popular slogan. “We” refers to our selves, in the full-blooded person-constituting sense. “Narratives” refers to the stories we tell about our selves and our exploits in settings as trivial as cocktail parties and as serious as intimate discussions with loved ones. We express some in speech. Others we tell silently to ourselves, in that constant little inner voice. The full collection of one’s internal and external narratives generates the self we are intimately acquainted with. Our narrative selves continually unfold.
Bickle and Keating cite Gazzaniga’s research with “split-brain” patients, subjects whose brain hemispheres have been separated surgically (typically to treat a severe form of epilepsy). This empirical neuroscience shows that the left hemisphere of the brain is hard-wired for language and hypothesis, and responds to the right hemisphere’s sensory inputs by creating narrative interpretations of our perceptions:
… Gazzaniga argues that the human brain’s left hemisphere … possesses the unique capacity to interpret — that is, narrate — behaviours and emotional states initiated by either hemisphere. Not surprisingly, the left hemisphere is also the language hemisphere, with specialised cortical regions for producing, interpreting and understanding speech. It is also the hemisphere that produces narratives.
These left-hemisphere functions, according to Gazzaniga, what he terms the “interpreter,” give us our sense of self, our personal identity:
The interpreter sustains a running narrative of our actions, emotions, thoughts, and dreams. The interpreter is the glue that keeps our story unified, and creates our sense of being a coherent, rational agent. To our bag of individual instincts it brings theories about our lives. These narratives of our past behaviour seep into our awareness and give us an autobiography.
How does this work? Bickle’s explanation is that we have what he calls a “little inner voice,” a running stream of narrative produced by the always active left hemisphere’s language centres:
One compelling study used PET imaging to watch what is going on in the brain during inner speech. As expected, this showed activity in the classic speech production area known as Broca’s area. But also active was Wernicke’s area, the brain region for language comprehension, suggesting that not only do the brain’s speech areas produce silent inner speech, but that our inner voice is understood and interpreted by the comprehension areas. The result of all this activity, I suggested, is the narrative self.
The interior narrative function of the left hemisphere’s language centres creates the same kinds of stories as we encounter externally. In effect, our public literary traditions are built of the same stuff as our personal histories, and for the same reasons, since we seem to be hard-wired to see the world in a certain way, which we then reconstruct when creating stories for others:
If we create our selves through narratives, whether external or internal, they are traditional ones, with protagonists and antagonists and a prescribed relationship between narrators, characters and listeners. They have linear plots with a fixed past, a present built coherently on it, and a horizon of possibilities projected coherently into the future.
How did we develop this story-telling capacity? Gazzaniga suggests that the interpreter provided an evolutionary advantage by reinforcing “a new capacity for relentlessly hypothesising about possible causal patterns, combined with an older, right hemisphere capacity to make probability-based decisions.”
In this second scenario, Descartes fares no better than he does in Dennett’s “multiple drafts” model. Rather than a separate, enduring entity, in Gazzaniga’s “interpreter” the self becomes a never-ending narrative, a story that the brain constantly spins for itself, a tale in which the “I” is not the author, but rather the protagonist.
Where does all this leave me, the self? Who knows just how far neurological research will take our understanding of ourselves, but one thing we can say with confidence: one place that all this new science doesn’t take us is back to the discredited realm of the immaterial soul.
Dennett denies the existence of a single entity, an “observer” in a “Cartesian Theater”; Gazzaniga’s description accepts the observer paradigm, but his “interpreter” is a non-unitary concatenation of physiological brain functions.
So far in this informal and intermittent series on self and identity, we’ve looked at theories which if true make four-dimensional space-time and the I’s inside our heads much less secure than we thought, or than we’d like. What are we to make of all this? If our world is a representation created by our minds, minds that are transactional moments of ever-shifting brain processes — what happened to reality? And what happens to those of us who are empirical realists?
Some of that discussion next time we take up this topic, in a final look at the ideas in Stephen Hawking’s The Grand Design, in a piece called The many worlds of M-theory, coming soon to this location.
Bickle and Keating’s article can be read in its entirety here.
A 1996 SCIENCE NEWS magazine article on Gazzaniga’s research can be read here.