The first thing I would point out is that this book is written by an expert in the field, and that sets the tone of the book. There is no breathless prose interspersed with misunderstandings, which you can get when a journalist presents a subject, but the down-side is that some of the language and concepts may be beyond the intelligent layperson, who is presumably the intended reader. They were certainly beyond me. That is not to say I got nothing out of the book. Once I had learned to not get to hung up on the tricky bits, I found it interesting and rewarding.
Shepherd’s main theme is that a lot of what we call flavour comes from the sense of smell, and that we humans are actually a lot better at smelling things than many give us credit for. Other animals may be better at detecting low concentrations of air-borne smells, but the human anatomy is better geared up for detecting smells retro-nasally, i.e. through the passage between the back of our nose and the mouth. It is the retro-nasal smells that help create the flavour of our food and drink. The other big advantage humans have when it comes to our sense of smell is brain size, which allows us to better use the information we get from the nose.
The book largely deals with the “how the brain create flavour” bit of its subtitle, and does that well. I found it especially intriguing that smell and taste receptors are connected to the brain cortex via completely different routes, finish up in parts of the cortex that are greatly separated, and yet the brain still manages to integrate these senses to create a unified impression of flavour. From this book, it is clear to me that we know so much about how this works, and how the process is affected by genetic differences, that it is impossible to continue to argue that flavour is a property of the food (or wine) put into our mouth. And yet Charles Spence, in his detailed review of the same book, thinks it is still up for discussion. Do read that review, though – I have great respect for his writing.
I was particularly looking forward to the “why it matters” bit. But I was disappointed. I was told how important flavour is, and how craving for food involves some (but not all) bits of the brain that have to do with drug addiction. But I did not see any support for the claim that neurogastronomy should inform policy making. Certainly a good case was made for the importance of flavour in determining how we eat, that that could be demonstrated without reference to neurogastronomy.
Wine was referred to a few times in the book, but for me the most relevant observation was that smell objects are represented in the brain in a very similar way to faces. In fact Shepherd is more precise – he likens them pointillist images of faces, where each type of odour receptor represents a dot, but seen at a distance the dots combine to create smell equivalents of colour and shade. He goes on to observe that familiar smells, like faces, are easy to recognise but very difficult to describe.
Finally, there was a suggestion supported by limited experiments that the more you are exposed to a smell in the long term, the more sensitive to it you become. So if you want to improve your sensitivity to the different aromas in wine, the answer seems to be to increase your exposure to them. Even if that fails to improve your sensitivity, it must help recognition mustn’t it? It works for faces at least.