This book is as good as a popular science book can be, and explains in easy terms some of the most important concepts in neuroscience. For this it should be widely read. However, Ledoux wants to explain the self, and not only to write a popular book on cognitive neuroscience. Now, given that it is very difficult not to accept that the self at some level is nothing but synapses, Ledoux does seem to base the self on neurobiological mechanisms. But this is no more enlightening than sayying that vision, attention, language, or even qualia are nothing but synapses, claims that at some level must also be correct. So one would expect the bulk of the book to develop principles that tie or at least correlate the self with brain mechanisms. Do we get this in Synaptic Self? well, yes and no.
Ledoux concentrates on memory, having in his last book focused on emotion. He explains memory systems from molecules to circuits, with the classical and most recent findings, including some from his own lab. He also gives a quick overview of the emotional systems of the brain, the working memory complex of the prefrontal cortex, and motivational systems of neuromodulator and brainstem and thalamocortical systems. He calls that the mental trilogy, namely cognition, emotion and motivation. Ledoux also wrote a nice chapter on some brain diseases that seem to alter these functions selectively. And thats it. Ledoux has explained the self. Or has he? Well, memory, emotion, cognition and motivation surely contribute to the making of the self, especially memory. How much of a self is left in a retrograde and anterograde severe amnesic? But this is not saying that putting them together is all the self is about. Its like saying vision, attention and waking are what consicousness is. Vision provides content, attention access, and waking a necesary condition for consicousness, but together they are not the phenomenon in question. I bring out consicousness because Ledoux says the really hard and important question in neuroscience is the self, and not consciousness. To me it seems almost silly to try to understand the former without the latter.
Ledoux then forgets about the feeling of the self itself, the possible bases of it on body schemas and body signals, the primacy of movement. He does touch on volition and free will, and is as naturalistic about these issues as one can be, which I think is a good thing. The final chapter presents 7 principles he can extract from his discussions, and meybe here we can find his theory of the self. Unfortunately, he seems just to add another thing, binding, to the picture. So binding, convergence zones, emotion and motivation, memory, placticity, hebbbian mechanisms of memory, together are the self. Again, I would say they are an important part of the self, but not the self itself. I may be wrong or maybe dogmatic about what would count as an explanation for the self. Maybe there is nothing more to the self than those mechanisms Ledoux lists. But work in theorethical neuroscience like by Damasio, or Patricia Churchland and philosophers like Bermudez show that the self is more complex than Ledoux seems to think.
At the end this book is of value, and I never said it did not make progress on the problem of the neurobiology of the self. However, it does not by any means solve it. It presents a nice theory of the integration of cognitive and affective mechanisms, and manages to cover a great deal of issues in simple terms, and that is always an achievement.