Neuroscientist David Eagleman begins his third book, Incognito: the secret lives of the brain 1, in panoramic Sagan-esque style, immediately striking a resonant harmony between lucidity and enthusiasm for the significance of his topic. The thesis? Human consciousness emerges from the physical attributes and activities of the brain, but is only a small part of the brain’s business; what else the brain is up to is normally inaccessible and mysterious, but our science, Eagleman asserts, is now uncovering its secrets.
In support, Eagleman uses optical illusions and striking case studies to demonstrate that common assumptions about reality – based on the sensory environment – are often unreliable. Brains generate an internal model of the external world that is only modified by sensory input, not created by it. Experiences of audition, sight, smell, touch, and time are created by the brain from the residual patterns of prior experiences in the form of conditioned expectations, which are then adjusted to accommodate incoming data. For example, did you know you have an anatomical blind spot in each eye called the punctum caecum? Probably not, because your brain fills in this large hole in your visual input for you (or is it hiding it from you?), but it’s there and easy to demonstrate. Further, Eagleman cites several examples of new sensory technologies being developed to replace lost, or to augment existing, sensory systems. The brain, he explains, is fully capable of adapting to and accommodating new inputs, adding the raw data to the internal model within which our consciousness resides.
But Eagleman doesn’t conclude his argument after establishing the existence of unconscious processing underpinning sensation synthesis and internal modeling – perhaps a comfortable enough endpoint for many. Instead, he insists that sensation is only the beginning; inaccessible, unconscious processing also drives instinct, thought, behavior, and decision making, and not just some of each, but most of all. Eagleman argues that unconscious automation of thought and behavior is beneficial on multiple levels – for speed, energy efficiency, and adaptability – and that we’re each adding to our catalog of automated processes all the time. Through learning, novel behaviors can be pioneered consciously and intentionally before being automated, that is, “burned into the circuitry” of the brain.
The mind, as he puts it, is a democracy: driven by conflict among neural constituents, and determined by consensus (or at least majority). In this democracy, we find a complicated reality that may be approximated by a much simpler two-party model because of the weight and authority wielded by two of the great neural parliamentarians, Reason and Emotion. Eagleman notes Greene and Cohen’s work in characterizing these systems before highlighting the “party” conflict dynamics in the temporal dimension. The secret of the brain’s success, according to Eagleman, lies in the overlap among its expert modules, that is, in redundancy – which allows for both robustness in the face of damage, and consensus when the path forward is clear.
But what, then, is the fate of consciousness – are our conscious selves only symbolic royalty, powerless and distant from the workings of the country, or, are we (that is, our conscious selves) more like the US president, deeply involved in long-term planning and foreign (interpersonal) policy, and required to intervene directly especially during crises? Eagleman suggests, citing Crick and Koch, that consciousness’s purpose lies closer to the latter. The complexity of our democracy – populated by innumerable limited-capacity, highly specialized experts that must contribute to our survival in a dangerous, dynamic environment – requires a central director to set common goals, assign tasks, and lead through the difficult process of change. OK, but then how can we understand consciousness in the absence of free will? Eagleman insists that the democratically-inclined wetware architecture of the brain leaves little room for it, or rather, it accounts for all the phenomena formerly filed under free will’s heading, and as he addresses in the book’s final chapters, this brings us face to face with the most consequent of our institutionalizations of the free will doctrine – crime and punishment.
Eagleman’s arguments, based on hard science and equally hard logic, seek to disabuse the reader of the fictions of autonomy, control, and free will, however natural or even essential they may prove to be. In establishing the existence, pervasiveness, and power of the unconscious parliament directing our steps, Eagleman opens the questions of identity and self-determinism to the full force of neurobiological determinism. This, I think, is a shift of popular perception necessary for progressing forward in the difficult and uncertain future humanity is busily building, but I have moderate but real concerns about the psychological danger that such a shift may entail.
Eagleman himself points to the tremendous energy cost of maintaining the illusions that support the assumed sovereignty of consciousness. It is fair to ask what selective pressures might have shaped such an expensive and extravagant conceit, and what cost to fitness might follow its dethronement. When I asked him directly about the possibility of cognitive enlightenment coming at such a cost, Eagleman referenced the many dethronements science has sponsored and Homo sapiens has survived (from Galileo’s impeachment of geocentrism to the mechanisms of selection and inheritance that moved man from the center of life on earth to the tip of one among all of life’s branches) as if this last assault on man’s vanity could be no different.
I wonder if there may be, after all, something different about our intrinsic belief in the sanctity and autonomy of our own consciousnesses – something based in our genetics and essential to the explosive appearance of the mind’s self-awakening over the last 50,000 years. Might there be some psychological cost to the mind’s exposure of a different kind than that charged by contradictions between religio-cultural beliefs (about the earth’s place in the universe, or humanity’s place in nature) and the clear evidence and counterintuitive conclusions derived from the scientific enterprise? Perhaps such a distinction doesn’t exist, and perhaps Homo sapiens can and will take this final shock of free will’s dethronement in stride and to its benefit, but I, for one, think the question deserves the attention of those of us actively engaged in the coup.
|Incognito: The Secret Lives of the Brain|
|Publisher||Pantheon (US), Canongate (UK)|
|Publication date||31 May 2011|
|Media type||Hardcover, Audio book, E-Book|
1. Eagleman D. Incognito: The Secret Lives of the Brain. Pantheon; 2011.
- A Visionary Week (leeware.wordpress.com)
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.