The Mind Is Flat: The Illusion of Mental Depth and the Improvised Mind, by Nick Chater

I am puzzled. I want to like this book. The notion that we are perpetually improvising, creating meaning from sensory information, is attractive to my jazz heart. I love the idea that we are composing on the spot what to decide, choose, say and perform. But it bugs me to hear that we have no desires, motives or fears.

Nick Chater writes clearly, and his book takes the reader through the classic problems of completion in perception and cognition: visual illusions illustrate that we invent most of our world (that is true!); psychological games trick people into defending a political position opposed to the one they had supported 10 minutes earlier; and a few more. Unlike other books on how the mind works that address these issues, however, Chater uses them to show that we truly invent most of what we think. The central thesis is that we create meaning from perception, solely in the present.

Yet the claim that there are no mental depths faces an objection from memory and how it is formed. The simple idea that desires – which Chater says do not really exist – can be thought of as evolving memories (all of them are) is sufficient to give desire the form of a strong bias that guides our decisions on the fly. If I accept Chater’s argument, that we invent our interpretations of situations, I then have to say that the systematic nature of the outcome of a particular person’s decision-making reveals that there is something that guides or tilts the balance in favour of certain emotions and decisions. It may be that it is our desire-memory that makes the difference.

Another surprising line of argument is the rejection of parallel processing in the human brain. Chater aligns himself with philosophers and cognitive neuroscientists who propose that we have one thought, and only one, at a time. I agree with this: the evidence for serial conscious thoughts, one after the other, is strong in classic psychology from the 1980s to current cognitive neuroscience. We solve one problem at a time, and multitasking is truly fast alternation between tasks.

However, I would not extend this to automatic processing because the same evidence shows that we process aspects of a scene in the visual, auditory, memory and interoceptive channels simultaneously. Unlike our conscious thoughts, the brain networks – which we do not have access to but which do most of the work underlying perception – work in parallel, constantly informing the slow conscious thoughts queuing up to take the spotlight.

I tried to write this review in one sitting, as a non-stop stream of conscious thoughts poured on to the white page, in an attempt to invent my desires and motives, emotions and analysis, because this is closer to the way Chater describes how we think. Yet I do not really believe that we think this way; I believe that my memories form my desires and that I am made up of unconscious biases that define who I am… Nothing is more refreshing in making you re-examine your own views than a book you disagree with.

Tristan Bekinschtein is a lecturer in the department of psychology, University of Cambridge.

The Mind Is Flat: The Illusion of Mental Depth and the Improvised Mind
By Nick Chater
Allen Lane
272pp, £25.00
ISBN 9780241208441
Published 29 March 2018