Perchance to Dream
YOU ARE JOLTED AWAKE FROM a terrifying nightmare. Your pulse is rapid, breathing shallow. Beads of sweat roll off your forehead into the soaked pillow clutched tightly in your clenched fist. It is dark. You're disoriented. The nameless fear that almost nabbed you in its jaws moments ago quickly fades out of focus and into a fuzzy, distant memory. As the seconds pass, the receding terror is replaced by a growing awareness of where, and who, you are. You are lying safe in your bed in the middle of the dark night. You slowly become aware of your surroundings: the yielding warm sheets, the dim red glow cast by the surrounding constellation of electronic devices in "sleep" mode, and the soft, gentle breaths of your loved one lying next to you, still fast asleep. You take a deep breath and try to distract your mind with happier thoughts in an attempt to ease yourself back to sleep.
This is likely a familiar, though hopefully infrequent, scenario to most of us. Psychologists, psychoanalysts in particular, have long been interested in the interpretation of dream states and what they say about the dreamer and his or her subconscious. Cognitive psychologists, on the other hand, have had a long-standing fascination with our wakeful mind and its processes. But what about the transition from dream state to full wakefulness? How do we explain, from a scientific point of view, this transition from sleep to consciousness? And more importantly, what can an understanding of its neural basis tell us about how brains "do mind"?
These questions and more are the subject that Dr. Antonio Damasio, a cognitive neuroscientist at the University of Southern California, explores deeply and thoroughly in Self Comes to Mind. Damasio provides a compelling big picture account of how our consciousness — and, more importantly, our sense of self — is a product and a process of our human brain. The picture he meticulously details relies on the disparate but connected disciplines of behavioral neuroscience, from comparative psychology and brain evolution to the intricacies of cutting-edge research — much from his own lab — on human cognitive neuroscience and neurology.
Before we begin, let's revisit the opening scenario. As we awaken from sleep, our consciousness undergoes a radical transformation composed of dramatic adjustments in neural processes. Some neural circuits go quiet while others come online. The entire orchestration of the symphony of mind unfolds like changes in a music score, and while there is no single, master conductor, Damasio posits that the decentralized process does have hot spots of top-down modulation linked by connections built over evolutionary time. These "command centers," for lack of a more accurate but succinct term, do one thing really well: They create our sense of self, our sense of being a protagonist in a continuously unfolding nonlinear narrative through which we can travel again and again in our memories and plan possible and even impossible futures. These circuits have been specially designed by natural selection to work with the rest of our perceptual, attentional, and memorial machinery to allow us incredible feats of counterfactual reasoning, from mere day dreaming to building highfalutin philosophical treaties or richly decorated fantasy worlds of pure fiction. At the center of these abilities lies our "self": that lonely kid in the playground of fantasy populated by his or her imaginary friends and foes. Thus, as you awake, you become self-aware. Your "self" becomes defined — its position situated within the context of your surroundings and unfolding timeline of events — and your streams of thought come into focus. You become the pinnacle of embodied cognition.
Feeling Up Myself
Perhaps more surprising is the fundamental role that Damasio posits emotion plays in building and directing our self and its goals. In effect, the myriad amalgamation of perceptions, feelings, and emotions are the self. These feelings, both primordial and our higher-level conscious ones, interface with the maps of the world generated by our nervous system to create the totality of our umwelt (the term invoked by the famous Estonian comparative psychologist Jakob von Uexküll to capture the notion of a creature's self-centered world). It is the marriage of feelings and percepts to the psychophysical maps of the mind — all orchestrated by several neural circuits that arose through evolutionary time to work in loose concert to organize and direct it all — that stand central to Damasio's framework for making sense of self.
To understand this framework, the book takes the reader through an ambitious journey of four parts. Part 1 covers the vast evolutionary prehistory of the self. Part 2 explores how the nervous system constructs self. Part 3 tackles consciousness and its relationship to the autobiographical self. The book closes in Part 4 with a discussion of how this new perspective of the human self impacts our daily lives as humans and what kind of role it plays in society.
Damasio expresses the fundamental tenet of the book early on:
I believe conscious minds arise when a self process is added onto a basic mind process. When selves do not occur within minds, those minds are not conscious in the proper sense. This is a predicament faced by humans whose self process is suspended by dreamless sleep, anesthesia, or brain disease.
I've been a huge fan of science fiction and fantasy all of my life. A fancy but decidedly impractical notion has arisen repeatedly in many such works (Robert A. Heinlein being, perhaps, the most prolific) that sheer complexity of an information processing device, such as a computer or artificial intelligence network, is sufficient for the emergence of consciousness. Some Rubicon of complexity must be crossed for intelligence to "wake up" and know itself. This notion is flawed, however, as there is no true self in these artificial creations in the same way that self processes have arisen and evolved in the animal kingdom. This is like comparing a house of cards with a real house, or a paper airplane with a real airplane. There is some superficial resemblance, and even some shared functional capacities, but no more. Biological creatures do not have a self in the way that they have a nervous or circulatory system. There is indeed a self, says Damasio, "but it is a process, not a thing, and the process is present at all times when we are presumed to be conscious."
That is, "self" is a function of the physiological activity, in the same way that learning, memory, cognition, and homeostatic processes are functions of biological physiology in action. This biological approach to conceptualizing self as a physiological process is both fascinating and more accurate than Cartesian "ghosts" haunting our biological "machines." This is not to deny that an artificial intelligence can have a self or be conscious, only that such properties do not automatically arise as a function of sheer processing power. They reflect a specially designed process with a particular function.
In the Beginning
Where did the self process come from? The journey starts in Earth's primordial soup over 3 billion years ago. Part 1 takes us through a plausible evolutionary history of self, drawing from comparative psychology, animal behavior, and evolutionary biology and neurobiology. In perhaps the most fascinating part of the book, the reader is taken on a journey tracing the origin and evolution of feelings, and the neural and psychological processes that govern the fundamental operations of a biological creature, from their humble beginnings in single-celled organisms and ultimately to the evolution of the human species and its capacity for self-knowledge:
Countless creatures for millions of years have had active minds happening in theirbrains, but only after those brains developed a protagonist capable of bearing witness did consciousness begin, in the strict sense, and only after those brains developed language did it become widely known that minds did exist.
Part 1 provides a succinct, yet highly informative overview of the way biologists view life in all of its forms and manifestations. It serves as an excellent primer for the uninitiated and a great review for those already in the know.
While Part 1 reveals a riveting historical tale, in Part 2, Damasio meticulously details the neurophysiological mechanisms behind the construction of self. The central idea is that self is a marriage between feelings, on the one hand, and mental maps and images, on the other:
Minds emerge when the activity of small circuits is organized across large networks so as to compose momentary patterns. The patterns represent things and events located outside the brain, either in the body or in the external world, but some patterns also represent the brain's own processing of other patterns ... In brief, the brain maps the world around it and maps its own doings. Those maps are experienced as images in our minds...
The images in the above passage refer not only to the visual representations constructed by the visual system in response to light entering the eyes, but to all percepts of sensory origin, including auditory maps and those produced by taste, smell, and touch. Even the deeply felt, perhaps mostly on a subconscious level, visceral experiences emanating from deep within our own bodies result in images that build on and inform our self:
The human brain is a born cartographer, and the cartography began with the mapping of the body inside which the brain sits. A spectacular consequence of the brain's incessant and dynamic mapping is the mind. The mapped patterns constitute what we, conscious creatures, have come to know as sights, sounds, touches, smells, tastes, pains, pleasures, and the like — in brief, images. The images in our minds are the brain's momentary maps of everything and of anything, inside our body and around it, concrete as well as abstract, actual or previously recorded in memory.
Damasio's messages are delivered in an easygoing, conversational voice, often conveyed in effective metaphors. The book is chock-full of such delicious prose, like the bits excerpted here.
Imagine the following scenario (a bit of counterfactual reasoning of which this book is about): As you walk to your favorite restaurant to have dinner with an old friend whom you haven't seen for years, you step off the curb and into the crosswalk at an intersection. Quite suddenly, an unexpected speeding car barrels through the red light — missing you by mere inches — and sets off a whole barrage of internal alarm bells of visceral origin. These internal signals instantly shift your ongoing goals, downgrading the navigation goal and bringing to the forefront threat-detection and self-protection goals, all the while interrupting your reveries of the "good old times" spent with your friend. Damasio does a beautiful job, in Parts 1 and 2 of the book, describing how the brain machinery not only constantly sets multiple goals all running in concurrent but overlapping and interconnected circuits, but also continually monitors these goals in the face of the continuous stream of new information brought through the sensory channels. Certain brain circuits exist largely to self-monitor the panoply of goals and to guide and nudge decision-making processes in response to the dynamic, constantly changing present moment — all producing an integrated self. In this view, awareness emerges as higher-order processes that monitor the needs of the integrated self.
Making Up One's Mind
Damasio lays out an interesting perspective on how the brain does mind. He first describes the variety of maps made in the mind in three categories: maps of the organism's internal structure and state (interoceptive), maps of other aspects of the organism (proprioceptive), and maps of the world external to the organism (exteroceptive). He then uses data from neurology and cognitive neuropsychology, enlisting brain imaging techniques (e.g., functional Magnetic Resonance Imaging or fMRI) and brain damage in neuropsychiatric patients as tools to discern the particular functions that various brain regions and neural circuits play in building maps and relaying them across the distributed neural network. Mind is ultimately made through the connections between and across the distributed network of neural circuits through special neural ensembles that relate maps from one area to those of another area. These coherent ensembles are necessary for an integrated self to emerge to guide the ship. Much as a ship commander does not run all of the ship's operations, working instead by influencing and guiding the sum total of contributing individual sailors, certain brain circuits seem to play a role like a commander, monitoring all of the channels so as to effectively and efficiently orchestrate the action-decisions that balance the myriad parallel goals of the self, but with a sense of coherency. Thus, Damasio's commander is not a homunculus inside the head, so to speak, and therefore escapes the trap of Cartesian dualism.
Damasio does an admirable job telling this story, employing clear explanations and cogent examples. Despite his efforts, however, I couldn't help but occasionally get lost in the details of the story, replete with an increasing cast of characters with such funny names like insular cortex, thalamus, and periaqueductal gray. Perhaps including more diagrams would have helped. Nevertheless, Damasio repeatedly provides succinct summaries at key points in the story to synthesize and distill the main ideas, helping the reader stay on track.
Now, all of the imaging and mapping capabilities of the brain, grand as they may be in building incredibly rich, detailed, emotion-laden and coherent representations of the creature and its world, would not be nearly as powerful in supporting the kind of fluid intelligence and creativity displayed by humans and some of our closer relatives were it not for the evolution of a specialized neural architecture called convergence-divergence zones. What do these convergence-divergence zones (or CDZ for short) do you ask? They are thought to build the patterns of interconnected events that become our conscious memories, thereby allowing exposure to only a single element from the original experience to trigger the recreation of the full-blown original memory; that is, they allow for pattern completion. Reflect on the last time you heard the beginning lines to a well-known tune, only to have the rest of the song pop into your head. In fact, it can be so infective as to haunt you the rest of the day, and even into your dreams. Individuals with post-traumatic stress disorder can be immediately thrown back in time to a virtual, vivid mental reenactment of a traumatic episode through mere exposure to a triggering event, such as the backfire of a car or the scent of a strong odor associated with the episode. These particularly salient examples demonstrate the work of CDZs.
Moreover, retrieval of rich memory sets from partial information in turn provides the neural substrate for counterfactual reasoning. That is CDZs not only let us reflect, but also allow us to fantasize and hypothesize:
In brief, the job I envision for CDZs consists of re-creating separate sets of neural activity that were once approximately simultaneous during perception — that is, that coincided during the time window necessary for us to attend to them and be conscious of them.
The special role played by CDZs, neural circuitry that has reached the most advanced degree of development in humans, has evolved, Damasio posits, as a special adaptation that brings self-monitoring processes to a whole new level. Enter consciousness, the topic of Part 3.
An I for an I
Part 3 shifts its coverage to the terrain of what it's like to be conscious and its relationship to the autobiographical self. There is much in this section that is reminiscent of the writings of contemporary philosopher Daniel Dennett (who has had a profound influence on me from the outset of my career over two decades ago) and his "multiple drafts" model of consciousness (partly a revised version of Gilbert Ryle's behaviorist philosophy), but updated and mapped onto the neurophysiological architecture described in Part 2.
A key insight about the adaptive function of consciousness: "the reason why conscious minds prevailed in evolution was the fact that consciousness optimized life regulation." And we return to the biological perspective that pervades the entire thesis of the book. Consciousness, like memories, perceptions, and even the self, is a process, or set of processes, designed by natural selection to regulate the activities and goals of the individual creature. How is life regulation achieved? To answer this important question, let's turn to the working definition of consciousness in the book to see what it reveals about its function. Consciousness has two basic ingredients, according to Damasio. First there is wakefulness, the property (or process) of being awake and aware of stimulus input. The second ingredient consists of the images discussed above; it is the interplay between neural circuits and brain regions that regulate wakefulness (sleep, vigilance, attention, focus, etc.) dispositions with the mapping and image-making neural machinery that results in the processes of, and therefore our experience of, consciousness. Yet this is not a willy-nilly all-over-the-place consciousness that does wonderful things for us like revel in rainbows and Jackson Pollock paintings, take pleasure in banquets of delicious foods and wine, or savor the sounds of a chorus or symphony.
Yes, consciousness affords us these pleasures, but it also has a very specific role to play: Conscious minds arise from establishing a relationship between the organism and an object-to-be-known. That is, consciousness is the process of an organism constructing a self-image, object images, and an image involving the relationship (spatial, temporal, tactile, dispositional, emotional, etc.) between self and object. The neurobiology of subjectivity (of consciousness) is the lynchpin that gives rise to the self as a protagonist in the world, an actor on the stage of life. This insight provides the key connection between the way a biologist views an individual, on the one hand, and the conception of an individual from the perspective of a humanities scholar, on the other.
The remainder of Part 3 leads the reader in a dance through the neural basis of consciousness and of the construction of self. The self, as experienced by a fully-conscious adult human, is argued to consist of a protoself, a core self, and, in humans at least, an autobiographical self. The protoself is "an integrated collection of separate neural patterns that map, moment by moment, the most stable aspects of the organism's physical structure" and is largely a product of an interactive mix of brain stem and cerebral cortex structures. The protoself is proposed to serve as an overarching view of the current disposition and state of the individual. The role of the core self is to monitor changes to the protoself produced by interactions between the individual and the objects in its world. This monitoring process allows for mappings of feelings and dispositions onto the objects that cause the change in the protoself so that the individual can do something to, with, or about that object:
The core self, then, is created by linking the modified protoself to the object that caused the modification, an object that has not been hallmarked by feeling and enhanced by attention.
The core self imbues the protoself with consciousness.
What is being added to the plain mind processes and is thus producing a conscious mind is a series of images, namely, an image of the organism (provided by the modified protoself proxy); the image of an object-related emotional response (that is, a feeling); and an image of the momentarily enhanced causative object. The self comes to mind in the form of images, relentlessly telling a story of such engagements.
What a Zen-like, one-with-the-object experience consciousness provides! Namaste.
Images of the internal and external worlds can be organized in a cohesive way around the protoself and become oriented by the homeostatic requirements of the organism.
Part 3 ends with a fascinating and detailed discussion of the neural mechanisms of the autobiographical self. The one you and I reflect on in our daily reveries. The one we hold at the center of the narratives we tell each other and ourselves. The autobiographical self provides our experience of being the same individual across our entire lifespan, thereby providing unprecedented ability to shape and build one's life, to have our dreams and long-term goals and work to make them come true. The autobiographical self draws on all of the components of the self described above and adds a layer of neural substrates that coordinates their interconnectivity to provide the feeling of being in charge as well as the feeling that one's personal history is a story about him or herself. The special neural substrates of the autobiographical self turn out, surprisingly, not to be the frontal cortical regions responsible for executive function and planning (the current darling of contemporary systems neuroscience), but the postmedial corticies (PMCs), of which I had never heard prior to reading Self Comes to Mind. What a fascinating tale Damasio tells about the unique architecture, location in the brain, and connectivity to other regions that provide the PMCs their special powers as a generator of the autobiographical self. The discussion ends with some revealing clues from sleep research and research on neurological conditions, such as Alzheimer's disease, coma, and locked-in syndrome, in which the patient is apparently awake but unable to respond to external events except in some minimal way (for example, through eye movements).
No discussion of consciousness, it seems, can be complete without a word about qualia, a term of phenomenological consciousness invoked to describe the specific subjective experience of sensing and perceiving. Why is red red? What makes the cloying seduction of a fine Barolo from Piedmont so elusive to describe (for me, at least) yet so powerful and uplifting? Why does pain have to hurt the way it does? How is it that a major chord in an anthem can be so exhilarating, while a minor chord in a requiem can be so somber and mournful?
I hypothesized that feeling states are generated largely by brain-stem neural systems as a result of their particular design and position vis-à-vis the body. A skeptic may well conclude that I have not answered the question of why feelings feel the way they do, let alone why they feel like anything at all. Here I both agree and disagree. I have certainly not provided a comprehensive explanation for the making of feelings, but I am advancing a specific hypothesis, aspects of which can be put to the test.
Neither the ideas discussed in this book nor the ideas presented by several colleagues working in this area can be said to solve the mysteries surrounding brain and consciousness.
Although Damasio does an admirable job addressing the issue of qualia in the final pages of Part 3, especially on highlighting the important interplay between emotions and feelings on the one hand and sensory experience on the other, it is, in the end, unsatisfactory. It appears that we must continue to duck the issue until a more scientifically tractable approach to the question of qualia — what some philosophers such as David Chalmers claim to be the real problem of consciousness — can be advanced, if ever. Some known unknowns may never yield to a complete explanatory theory in the realm of observation and testing. This, of course, is no excuse not to try:
The idea that we have a firm grasp of what the brain is and what it does is pure folly, but we always know more than we did the year before and much, much more than one decade ago.
Such optimism is refreshing, and contagious.
Finally, in Part 4, titled "Long After Consciousness," Damasio extends the functional account of consciousness as self/life regulation to more speculative and broader issues of self-governance and our place within society. Self is a biological adaptation for optimizing life processes and the individual's responses to the world. Consciousness provides the neurocognitive resources to focus attention on oneself. It births meaning to one's life; it gives a creature something to be about and a purpose. Moreover, the neural machinery of feelings, imagery, and memory provide the tools for running online simulations of oneself in hypothetical situations and settings. The counterfactual reasoning and fantasies we use in our daily lives, for everything from daydreaming about a vacation by a warm, sunny beach to figuring out the best route home after encountering a closed road on our usual one, to obsessively playing over in your mind the faux pas you made on a first date, wondering why you didn't keep your mouth shut, are the gifts of a conscious mind. They allow one to learn off-line, to plan a trip or think about what's stressing you out so much that it drives you to daydream about escape, to have more options available when navigating home, to rehearse better what you will and won't say on a future date. We can learn from our mistakes. And the best mistakes to learn from are those we never made in the first place. Karl Popper famously said that our ability to reason counterfactually and spin scenarios in our minds "permits our hypotheses to die in our stead." This is the purview of the autobiographical self.
The book ends with interesting discussions of what this biological framework of consciousness and self suggests regarding our systems of justice and the social and moral systems of Man, the civilized creature:
Now there is a growing fear that evidence regarding brain function, as it becomes more widely known, may undermine the application of laws, something that legal systems have by and large avoided by not taking such evidence into account. But the response has to be nuanced. The fact that everyone capable of knowing is responsible for his actions does not mean that the neurobiology of consciousness is irrelevant to the process of justice and to the process of education charged with preparing future adults to an adaptive social existence. On the contrary, lawyers, judges, legislators, policy-makers, and educators need to acquaint themselves with the neurobiology of consciousness and decision-making. This is important to promote the writing of realistic laws and to prepare future generations for responsible control of their actions.
Some will be uncomfortable with Damasio's physical-monist peeking-under-the-hood of our most private inner workings, and feel that he has reduced human selfhood to being no better than a purposeless machine, a sort of glorified watch or micro computer. Yet the reader comes away from the book with just the opposite impression. We are left with a fuller understanding of the physical mechanisms of self that, in turn, reveal the power and beauty of our autobiographical self as an efficient and clever (pardon the teleological shorthand) solution to the unique adaptability and creativity displayed by the human species. The protoself inherited from our animal ancestry has extended to an autobiographical self, that in turn, has extended during human evolution into a social (and sociopolitical) self. We can now construct a social projection of our self that we display to others and to society at large (thank you, Facebook!). By doing so, we are empowered to relate to other minds, to build our living systems of ethics and morality, and revel in the richness of our experience as living, feeling beings — through art and science, through sex and food, through war and play. The science of self does not diminish us one iota, but lifts us up to a thing of wonder and beauty and glory. Indeed, we become a thing worthy of scientific study.
Damasio's own words sum things up best:
And what is the ultimate gift of consciousness to humanity? Perhaps the ability to navigate the future in the seas of our imagination, guiding the self craft into a safe and productive harbor. The greatest of all gifts depends, once again, on the self and memory. Memory, tempered by personal feeling, is what allows humans to imagine both individual well-being and the compounded well-being of a whole society, and to invent the ways and means of achieving and magnifying that well-being. Memory is responsible for ceaselessly placing the self in an evanescent here and now, between a thoroughly lived past and an anticipated future, perpetually buffeted between the spent yesterdays and the tomorrows that are nothing but possibilities. The future pulls us forward, from a distant vanishing point, and gives us the will to continue the voyage in the present.