Back in January I reviewed Mark Solms’ new book on consciousness for the Literary Review. The review is reproduced here with permission.
The science of consciousness is having a bit of a moment. Long confined to the margins because of concerns about how experimental methods could possibly get a grip on the vagaries of subjective experience, consciousness has become neuroscience’s glittery new thing, the subject of colourful theories, packed-out conventions and the wildest of claims. Understanding how that blob of matter between your ears can experience the sound of a loved one’s voice or the perfume of white tea has become the holy grail of brain science, with implications for artificial intelligence and the ethics of dealing with the dying and the not-yet-born.
A scholar and clinical specialist in brain damage as well as a trained psychoanalyst, Mark Solms is perhaps best known for founding the niche field of ‘neuropsychoanalysis’, the aim of which is to integrate the wisdom of psychodynamic theory with the advances of brain science. No surprise, then, to see him starting his journey to the source of consciousness with a figure who has an uneasy status in neuroscience: Sigmund Freud. As psychology undergraduates are still taught, Freud is the mercurial character who gave us an entire conceptual system for understanding emotions but said little that could stand up in the laboratory. It is Freud’s insights into the affairs of our hearts, along with some tantalising glimpses of how he understood them to be instantiated in the brain, that provide the raw material for Solms’s breathless new analysis of how consciousness comes to be. The title of his book might easily have been ‘Freud was a Neuroscientist’.
It’s all about feelings, then, not thoughts or words or the computations of an information-processing brain. No one gets out of bed without them, and consciousness needs their oomph too. Solms argues that our failure to come anywhere close to solving the mysteries of subjective awareness stems from our obsession with the biggest and apparently most important part of the brain: the cerebral cortex. Inspired by his own work on the neural mechanisms of dreaming, he argues that it is actually the deep and evolutionarily ancient part of the organ, the brainstem, that makes it all happen.
There is nothing new in the recognition that this structure is essential to arousal, motivation and emotion. Solms reverently describes the contributions of others in this field, such as Jaak Panksepp, whose work put neuroscientific flesh on Freud’s intuitions about the basic drives that keep us all fretting, lusting and searching. The substantial addition is a newly popular approach to thinking about the brain’s function: predictive coding, also known as predictive processing. Put simply (and Solms does an outstanding job of explaining it to the general reader), the brain does not hungrily acquire information about the outside world and use it to build up a model of it. Rather, it starts with its own model of what lies beyond, using that to predict what is out there and to suggest what to do about it, piling every effort into minimising uncertainty.
Crucially, for Solms, that uncertainty is felt as conscious experience. Consciousness is our awareness of the slippage between how we expect the world to be and how it actually is. Its purpose is to tweak the precision of our predictions, thus minimising the amount of uncertainty in the system. The cortex – the cauliflower in your skull that you probably think is doing all the work – actually has a secondary role. The real effort goes on deep down in the brainstem, in the unprepossessing structures known as the reticular activating system and the periaqueductal grey. No organism that lacks these structures has ever been suspected to be conscious. Humans, meanwhile, can lose most of their cerebral cortex and still show all the relevant signs of being aware.
Freud is the book’s presiding genius, and Karl Popper’s critique of the unfalsifiability of his theories pops into the reader’s mind on occasion. There are all sorts of reasons why consciousness might have evolved, and making us aware of the uncertain nature of our predictions may be just one of them. Much of the argument relies on evolutionary just-so stories that can probably never be tested, although there is a vertiginous section on current attempts to hold it all up to empirical challenge through the construction of an artificial consciousness. Part of the problem is that predictive processing is more a framework (within which specific hypotheses can be built and tested) than a theory in itself. Although the promise of the approach has been amply demonstrated in fields such as visual perception, its deep value and novelty are not as widely accepted as Solms would have us believe.
Solms is also oddly silent about what consciousness is like, not once asking how we might gather some actual evidence to answer that question. The main competing theories are dismissed with bravado in a single paragraph, and philosophical arguments against Solms’s brand of materialism are handled with a non-philosopher’s zeal. At this point in history, however, failing to provide a full account of consciousness is not something to be ashamed of. In trying to complete Freud’s project, Solm has provided a valuable service with this bold, thorough, occasionally infuriating and always wildly ambitious book. Whatever our ultimate explanation of consciousness, feelings will be a big part of it. After all, as Freud and other great writers have understood, they are the reason why we ever do anything.