A David Redish, The Mind Within the Brain: How We Make Decisions and how those Decisions Go Wrong (Oxford: Oxford University Press 2013) 392 pp. £27.49 Hb. ISBN: 9780199891887
Redish’s book is ambitious in its scope and style; not only does he want to explain how action-selection systems work in the brain, but also how they malfunction whilst delving into the philosophical and ethical consequences of analysing the mind in such a manner. Moreover, Redish aims to make his book as accessible as possible, which is no mean feat given the neurocentric viewpoint that the book adopts. The Mind Within the Brain achieves all this with grace; Redish does not presume too much background knowledge about the area and where more context is needed, he points to papers, footnotes and appendices. It is very much left to the reader how far down the rabbit hole they wish to go. In addition to supporting his points with the academic literature, Redish supplements the content with anecdotes, pop-culture references and humour. Not only does it make the text more enjoyable to read – which can come as a relief to someone with a non-scientific background – the examples that Redish gives help to further the understanding of the topic. For example, Redish recounts the story of driving home and missing his turning, seemingly on autopilot and driving towards where he used to live. This is something nearly all of us have experienced, thus it puts the procedural decision-making mechanism into context for us and gives the abstract concept of mechanisms a grounding in lived experience.
The main tenet of the book is that brains are decision making machines, and it is from this that each chapter aims to build upon or explain this idea, bit by bit. Redish is careful to make each step clear and each chapter is additive of the last, with the aim of ultimately explaining how, given these mechanisms in the brain which we use to make decisions, do we make bad decisions? This is an especially pertinent question from the first-person observer – as Redish notes, we feel like we make our decisions consciously and rationally and yet the alcoholic, for example, cannot help themselves but to have one more drink even when they know it is bad for them. The starting point for this is value (Part One, chapters three to five). In general, we seek out things we desire – and certain things become desirable to us through the psychological mechanisms that have ascribed certain values to things for us – which are brought about through the action-selection mechanisms Redish goes on to explain in depth in Part Two. What Redish highlights most importantly in these chapters on value and risk is that not only do we come to value or associate things via different means (such as through reinforcement or aversion due to different stimuli, eg pain or reward), which makes the creation of our value systems highly complex (especially when you add into the mix the physiochemical elements of the brain such as dopamine which can allow or inhibit certain activity in the brain), but we are also extremely bad at judging the values of objects. For example, we judge £3.99 to be considerably different in price from £4.00, such that we would consider buying something priced at the former but not the latter. Indeed, this in the motivation behind many ninety-nine pence stores – businesses are very aware of our fallibility in judging value. So Redish seems to highlight that even the most rational of us all may still slip up and make wrong judgements, leading to poor decisions.
From this, Redish moves on the next section to break down and analyse the systems that make decisions in the first place. He predominantly discusses, in turn, reflexes, the Pavlovian action-selection system, the deliberative system and the procedural system (with particular emphasis on the last three). But, we do not simply act or make decisions in a vacuum; all of our decisions take place within a context, ie the environment, which requires some situation recognition, argues Redish. As situations constantly shift in emphasis, and we take in new information whilst retaining some of the old, we must be able to recognise similarity and differences amongst these situations. For Redish, this requires constructing a narrative where events are sequential – not static or frozen. In part, this may be to do with memory (as discussed in Part Three, Chapter Sixteen). Part of the reason people with Post Traumatic Stress Disorder (PTSD) experience flashbacks in the way that they do is because they experience a semantic memory (to use Redishs’ words 'I remember that') as episodic memory ('you are there'), hence they feel like they are reliving that experience. Thus, if you are experiencing your current situation to be episodic in this way, and it is a traumatic situation, this will affect your Pavalovian action selection system which deals with emotionally motivated decisions. Thus, someone with PTSD may act ‘out of character’ for the situation or context they are actually in. Redish points to a dysfunction with the hippocampus for this behaviour, given research that suggests a strong relationship between this brain region and memory.
Redish goes on to explain the behaviour of various illnesses, such as gambling addiction, in Part Three using understanding and analysis from the previous section, as well as providing grounding for his hypotheses with empirical evidence and knowledge of the physiochemical structure of the brain (just as in the PTSD case). Thus, all behaviour becomes firmly rooted in the physical nature of the brain and all its strengths and weaknesses. However, the last section is perhaps the most intriguing as it deals with the philosophical consequences of such physicalism of the mind. For example, he discusses moral responsibility and selfhood given that much of the decision making seems to happen off-line. The Pavlovian action-selection system, in particular, accounts for evolutionarily learnt responses (like salivating when we see food). Redish argues we are still accountable for our actions despite our decisions not coming from a totally free will. At times, Redish seems to gloss over a lot of philosophical theory (such as Searle’s Chinese Room which has stirred debate in the fields of philosophy and artificial intelligence for decades but is not afforded more than a few paragraphs) and is critical of fairly old philosophical theories of mind (such as Descartes’ dualism). In more recent times, philosophers of mind have done much more in integrate the neuroscientific and computational world view into their theories (such as the rising prominence of Bayesian models of mind), so the last section could have done better to analyse or acknowledge that work. That said, The Mind Within the Brain is a very valuable introduction to the neuroscientific paradigm and to understanding how we make choices. It is an enjoyable read, easy to relate to and very educational.
Jodie Russell, University of Edinburgh