187 of 190 people found the following review helpful
on August 15, 2003
The book is an introduction to neurology from the particular viewpoint of the synapse and associated biochemistry. The author's specific interest in the field is experimental research into fear circuits in the brain, and the book shows this interest well and it forms the bulk of the examples. It is not the first book in the field that i would recommend to someone just getting interested, it is an "advanced intro" if that is possible, just a little hard going if you have no idea of the terminology or general structures. But it is written to the educated laymen, doesn't require a college degree to understand it, and is a welcome addition to my expanding library on the philosophy of the mind.
The book is well written, flows nicely until the near end,(drags a little just after chapter 6 however, that is why a 4 not a 5 rating) i'd recommend "synaptic sickness" be moved to an appendix if it couldn't be integrated into the body of the book better. The scholarly apparatus is kept to a minimum yet the push to ratify/justify the new knowledge via experimental data and reference to other scientists work is clearly evident and makes the book a good intro to the field, as further study is facilitated. I found the use of concrete experimental examples and the prolific use of diagrams (especially figures 6.4 - 6.6) particularly good(very superior), the book was always engrossing and a stimulating read, not common in books written by scientists who are not teachers as well.
As to particularly important ideas: i would point to chapter 6= "small change" and the systematic analysis of Hebbian plasticity and how long-term potentiation supplies the synaptic justification for memory and learning the key chapter in the whole book. The chapters before are introductory prologue to this idea, and the chapters subsequent are particular examples of how Hebbian plasticity and synaptic change unlie the circuits of the brain and hence become who we are.
And unusual emphasis(compared to the field as a whole) is on the emotional side of the triad: cognition, emotion, motivation, this is due to the author's interest and last book as a result of his professional research into fear circuitry. I appreciate the emphasis as a long overdue correction to neurology being somewhat, like philosophy of the mind, concentrated on the cognition part of the equation. With this emphasis and direction much of the book dedicated to showing fear circuits and like analysis means this ends up with teaching you a wider view of the brain than most introductory books. A good thing.
So i wholehearted recommend the book to anyone who had the patience and interest to finish reading this review. thanks.
103 of 112 people found the following review helpful
on March 23, 2002
LeDoux starts his first chapter with a quote from Bart Simpson: "Dad, what is the mind? Is it just a system of impulses or something tangible?" My kind of humor.
LeDoux's Synaptic Self is a wonderful book loaded with clear understandable explanations and insights (his wife, a "fantastic writer," assisted) on how the brain works based on the most current neuroscience (e.g., how neurons/synapses/neurotransmitters/neuro modulators work/don't work, implicit/explicit learning/memory mechanism explanations, nature/nurture considerations, the "mental trilogy" of cognition/emotion/motivation, and much more). The book's bottom-line, he writes, is "you are your synapses." With this book, "know thyself," and even fix thyself, seem more attainable. It's a book I'll reread/study for a while.
The following are quotes from the last chapter:
Life requires many brain functions, functions require systems, and systems are made of synaptically connected neurons. We all have the same brain systems, and the number of neurons in each brain system is more or less the same in each of us as well. However, the particular way those neurons are connected is distinct, and that uniqueness, in short, is what makes us who we are.
What is remarkable is that synapses in all of these systems are capable of being modified by experience... Emotion systems [as an example]... are programmed by evolution to respond to some stimuli, so-called innate or unconditioned stimuli, like predators or pain. However, many of the things that elicit emotions in us or motivate us to act in certain ways are not preprogrammed into our brains as part of our species heritage but have to be learned by each of us. Emotion systems learn by association - when an emotionally arousing stimulus is present, other stimuli that are also present acquire emotion-arousing qualities (classical conditioning), and actions that bring you in contact with emotionally desirable stimuli or protect you from harmful or unpleasant ones are learned (instrumental conditioning.) As in all other types of learning, emotional associations are formed by synaptic changes in the brain system involved in processing the stimuli. Some of the brain's plastic emotional processors include systems involved in detecting and responding to danger, finding and consuming food, identifying potential mates and having sex.
Because synaptic plasticity occurs in most if not all brain systems, one might be tempted to conclude that the majority of brain systems are memory systems. But [as LeDoux argues in chapter 5], a better way of thinking about this is that the ability to be modified by experience is a characteristic of many brain systems, regardless of their specific function. Brain systems, in other words, were for the most part not designed as storage devices - plasticity is not their main job assignment. They were instead designed to perform particular tasks like processing sounds or sights, detecting food or danger or mates, controlling actions, and so on. Plasticity is simply a feature that helps them do their job better.
Functions depend on connections: break the connections and you lose the functions...
From LeDoux's Synaptic Self
138 of 153 people found the following review helpful
on April 22, 2003
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.
45 of 48 people found the following review helpful
on July 19, 2002
Joseph LeDoux has written an exciting book that captures the current state of research in neuroscience. He makes life easy for the lay reader by thoroughly covering not only his own research and theory but that of most other points of view both contemporary and historical thus helping to place his work in a context that gives the reader the feeling that he is reading something on the cutting edge. He is so thorough that one almost thinks that he gives a little too much time to the philosophical approach but at least he stays away from burying the reader in qualia.
In a nut shell, LeDoux makes his argument that Hebbian plasticity is alive and well and that the mechanism for learning and memory is located at the synapses through the action of the neurotransmitters. You almost feel that, by God, he's got it right. The interaction of different neural loci such as the hippocampus, amygdala and prefrontal cortex are pictured as creating interconnecting networks that craft our responses to the environment, both external and internal. These are all made coherent by wrapping them in the mental trilogy of cognition, emotion and motivation. My only concern is when he mentions the retrieval of stored information and the comparison of present neural information with previously stored experience. This implies that an agent is lurking about conducting these activities. It's the homunculus rearing his ugly head. He also leaves out the interesting research conducted by Benjamin Libet on the disparity between response and the intention to respond. But these are small matters for there is much to fascinate and inform the reader who is fortunate enough to come across this book.
LeDoux also provides an interesting chapter on synaptic sickness. This chapter could stand on it's own though it flows elegantly from the previous theory. It gives a cogent explanation for mental illness and the promising approaches to it's treatment at the level of neurotransmitters and synapses.
There is much to like in this volume and one hopes that more is on its way.
19 of 19 people found the following review helpful
on July 21, 2006
Format: PaperbackVerified Purchase
Joseph LeDoux's book Synaptic Self is one of those works that is so dense with material, it may take a second run through to really appreciate it all. Although probably written for a general audience, it is not an easy read. Don't expect to be able to zip right through it in a few days. His descriptions of the central nervous system, how it develops, how it functions, and how it matures, is very detailed. It gets down to the chemistry of the process and into the sub-areas of brain topography in a much more thorough way than many books of this kind tend to do. I have a health care background and started my career as a neurology nurse, and it still took me some time to go through the material.
The book is a wonderful compendium of both the history of the research into neuro function and of the more recent discoveries. The author does a splendid job of synthesis for the reader; he presents a very balanced report of what is believed about brain function and the concept of self and of the literature on the topics. He presents theoretical models by himself and others and integrates them into a more coherent whole by pointing out where the likely weaknesses are and where research is still needed. This requires a very thorough knowledge of the recent literature and of the field in general, which requires a great deal of time and dedication to do well.
The newest information was of considerable interest to me. It certainly made me realize how far behind I was with respect to what is understood already about brain/mind functioning and about the development of the self. Information on the function of the working memory, especially on why we forget the way we do sometimes, was very intriguing and made considerable sense (p. 175), as did the concept of the "executive" function in decision making (p. 178). What I found most practical was the author's placement of the material in a health care context. The last chapter is devoted to the treatment of depressive and anxiety disorders. Some of the medications that have arisen for the treatment of these problems over the years are familiar to me from my career as a nurse, and it was interesting to understanding the underlying principles of their effect and why they are prescribed.
I was especially pleased to see that the author was not "lazy" in dealing with his citations either. He includes not only a list of footnotes for each chapter at the end of the book, citing and explaining his references, but also includes a bibliography of these at the end as well. So many books, often by very competent authors, let their footnote citations serve as their only bib, which means one has to go through every entry to mine for further reading materials. While some of these entries are older ones, mostly those dealing with historical material and early research, most of them are dated 1996 and later. The names listed are virtually a who's who of the neurosciences and experimental psychology. Several books might make good starting points for those wanting to know more. The material cited is, however, mostly journals of original research, always a good sign. While the average general reader might find some of these difficult to obtain, the student should find many of them in their periodicals department or their biomedical library if they attend a university.
45 of 52 people found the following review helpful
on August 5, 2006
"Synaptic Self" is a worthy follow up on LeDoux's seminal work "The Emotional Brain" which was published in 1996. Before starting this book, if you are a believer in mind-body dualism, you have to suspend your belief and accept that we are entirely the product of our nervous system. That is, our behaviors, thoughts and emotions, indeed our personality, are entirely created by our brain and nervous system. With that premise, LeDoux takes us through the neuronal organizations and brain circuits that are responsible for what he calls the mental trilogy of cognition, emotion and motivation. He then explains how these brain circuits are coordinated and unified to make a person who he or she is. As the title of the book implies, the core of LeDoux's assertion is that the mental trilogy ultimately exists at the synaptic level. In other words, as he puts it, "You are your synapses. They are who you are."
Some of the explanations in the book are very basic, even to the readers who have little prior studies in neuroscience. On the other hand, some of the explanations of various brain circuitries and their schematics may be difficult to process for a reader without a fair amount of knowledge in this field. LeDoux certainly has not figured out the neurobiology of the self; I don't believe he himself contends that he has either. But, he definitely gives the reader a lot to ponder. Overall, I consider this book a decent review of some of the recent literature in neurobiology of cognition and emotion. My main problem with the book was that the chapter on the biological basis of major mental disorders was superficial and seemed to unnecessarily flatter the field of biological psychiatry.
49 of 57 people found the following review helpful
As other people have written very complete reviews already, I just had a few miscellaneous comments I hadn't seen elsewhere, so I thought I would make them here.
First, a caveat. Although I'm not a professional neuroscientist, I have a strong background in both psychology and the neurosciences, so I didn't find the book difficult to read. But most people would be advised to try a more popular book on the brain before tackling this one. A couple of other reviewers here also mentioned that.
But on to my main comments. This book attempts to explain the self in neurobiological terms. Influenced perhaps by 2400 years of philosophical and psychological speculation on the subject, neuroscience has recently taken on the task of trying to explain it too. Without getting too far into all the technical details, what has become clear from recent research is that consciousness isn't a unitary phenomenon in the classical sense--it results from the coordination and integration of distinct and separate brain areas and mechanisms. Hence, the classical idea--and our normal perception of consciousness as a discrete and unitary entity--is an illusion. And the same goes, as Ledoux shows, for the phenomenon of the self.
So far so good. My only problem with this is that consciousness and the sense of self, although they impress us as the most important and immanent aspects of our mental life, may be ultimately unimportant. Although interesting, it is quite possible that they are simply an "epiphenomemon" or side-effect of a brain that is complex and highly evolved enough to contain an internal representation of itself, as if one had programmed a big computer to act like it was self-aware. In other words, although consciousness is nice, it may not be important or necessary to our survival. (And considering all the suffering that consciousnesses and selves are subjected to in this life, perhaps we'd all be better off without them). :-)
Although not the main focus of the book, I'd like to say a few things on the subject of biophysical reductionism before I conclude this review. Many people seem loathe to consider themselves just a collection of atoms, molecules, synapses, and nerve cells--perhaps because it doesn't seem to leave much room for the soul. Ask yourself, since the brain consists of over 14,000 major and minor brain areas and nerve pathways, where exactly would the soul be located? In the frontal cortex, with its relation to personality and long-term motivations? In the thalamus, with its function as a sensory relay and termination station (some sensations are processed in the thalamus--such as orgasms)? Or how about the limbic system, with its important functions in more primitive motivations and drives? The main point is that all brain areas have specialized functions. Being "the soul" doesn't seem to be part of the picture.
But getting back to the reductionism question, the fact that we can't totally reduce behavior to biology doesn't mean this isn't the case. It just means we don't know enough yet. However, even if we never learn enough to rigorously reduce behavior to biology (and I suspect that will be the case, given that the brain has 60 trillion neurons with between 3,000 and 100,000 connections each, so we'll probably never get the entire brain mapped), it seems pretty obvious that consciousness still depends on the brain. This is clear from the many degenerative brain diseases that progressively damage critical areas needed for memory, personality, and ultimately the self, to the point where the person is no longer conscious and eventually becomes completely brain dead, with the amount impairment being proportional to the amount of nerve damage.
Well, I didn't mean to dwell on such a morbid subject, but I can't think of a better demonstration that we are all basically our "brains."
Overall, this is a well written, interesting, and enjoyable account on a fascinating subject for those with some background already in the neurosciences.
11 of 11 people found the following review helpful
on December 6, 2009
As part of a class assignment for an introductory neuroscience class, I was required to read reviews of neuroscience books written by my classmates. Two of the reviews that I read impressed me to the point that I was prompted to the read the books; the first was VS Ramachandran's Phantoms of the Brain and the second was Joseph LeDoux's Synaptic Self. Reading these reviews by my classmates proved to be a valuable experience as I found both books to be extremely good reads. If I had to choose between the two, I would recommend Phantoms of the Brain as it is more accessible to the average reader, but Synaptic Self is a worthwhile read for those who can navigate through the text.
The main focus of the text concerns the theory that synaptic connections are the keys that make us who we are. Many understand that elements of the mind, thought processes, and personality originate in the brain but it is difficult to describe the neurological origin of selfhood. LeDoux proposes a new theory that claims experience shapes neurology and neurology shapes experience. He unites the concepts of the role of memory in selfhood and the role of synapse firing in brain interactions to create a unified theory connecting synapses to our sense of self. The most important element in this context is the synapse, which serves to trigger brain functions and convey information. Synaptic connections are plastic, shaped by a person's experiences and interactions. Subsequently these plastic connections give rise to unique thoughts and feelings. Memory is the result of synaptic activity as well, which helps to establish personality and a sense of self.
LeDoux begins the text with an anatomy lesson explaining what neurons are, what synapses are and how they connect neurons, and how these connections contribute to brain functions. He then moves to the discussion of nature vs. nurture. He gives his opinion on how nature and nurture come together to combine to shape the synaptic organization of the brain. Elaborating on this process he says neurons that fire together wire together suggesting that experiences shape the organization of neurons and the changes in organization serve to alter future experiences. LeDoux stresses throughout the text the importance of learning and memory with respect to the formation of the self because as he says, "without learning and memory the self would be an empty expression of genetic constitution".
The book continues with LeDoux explaining how neuronal circuits can change based upon what is learned and remembered with synaptic activity playing a large role in this transformation. He goes on to explore how various brain systems including thinking, emotion and motivation interact with each other to determine who we are. He also goes on to look at the ability of his theory to aid in the understanding and treatment of several mental illnesses such as schizophrenia, depression and anxiety disorders.
The organization of the text is helpful in the understanding of LeDoux's theories as the concepts flow nicely from one to the next. It is very well written, although at times it can be a bit difficult to understand for those less familiar with neuroscience. Overall, the book is mostly accessible with the few advanced sections not detracting from the overall essence of his work. For reader's that are looking for a good book to get an introduction into the subject this may not be the best choice because the language may be frustrating at times. This seems to be a mid-level read with respect to difficulty level. However, for those that can handle it the text will not disappoint; it is engaging and thought provoking the whole way through. LeDoux writes like a scientist in that he stays fairly close to his working thesis for the duration of the text and mainly sticks to the points that serve to enhance his arguments. The text has little entertainment value for those not interested in the facts and theories he presents, but for those that dream of neuroscience at night and whose eyes light up at the sound of the word neuron, this will certainly be a worthwhile read.
10 of 10 people found the following review helpful
on September 11, 2005
This book is well conceived, and executed with good, but mixed success. I learned an awful lot, found lots of clear, insightful writing, but was sometimes frustrated.
There are different kinds of neurons, but the primary basis for brain function is the formation and regulation of synapses, which is influenced by genetics, as well as the pre-natal and post-natal environment, including learning. LeDoux provides a clear understanding of the basic biochemistry of synapses, as well as "long term potentiation", and connects the latter to learning and memory. He then delves into our systems for emotion and motivation, and even provides a point of view on how consciousness comes about. He builds on this so that in the penultimate chapter he is able to discuss what is known about the causes of several psychiatric disorders, and how drugs treat them.
In the psychiatric drug chapter, the discussion of schizophrenia was clear, the discussion of depression was not. I believe that this reflects the fact that more is understood about schizophrenia, and that the mechanisms are apparently simpler than for depression. There are other subjects like depression, e.g. the roles of the hippocampus, where the truth is complex and not currently well understood. With such subjects, the tendency that LeDoux has to discuss in some detail the historical evolution of our thinking seems to make things harder to understand rather than simpler, as the reader tries to absorb multiple complex and not fully satisfying ideas.
LeDoux is wonderful at explaining just what an experiment or study shows, and what it only suggests and why. Thus, despite having read a number of previous discussions on the research findings about identical twins raised separately, I still learned a lot on this subject from LeDoux. When LeDoux veers from the concrete, to discussion of terms such as the self and emotion and motivation, he does not do a particularly good job, and can get repetitious. What is needed are clear and explicit operational definitions, which are very different from historical definitions and common usage.
Unlike some other reviewers, I valued the last 2 chapters, both for what they had to say, and as kind of a review of the previous material. On the other hand, I suggest the reader can safely skip chapter 1, and then possibly read it at the end.
For a less challenging follow up to this book, drawing more on psychology and social psychology, I recommend "Strangers to Ourselves: Discovering the Adaptive Unconscious" by Timothy B.Wilson.
10 of 10 people found the following review helpful
on December 15, 2010
Format: PaperbackVerified Purchase
A retired physician whose principal hobby is neuroscience, I've read many books on the subject. This is the best. Certainly there are more technical, in-depth publications if one is after detail, authority, and expertise in a paticular area of neuroscience. But that level of reading is probably better approached through peer reviewed journals than popular books. For an overview of the advances in neuroscience research over the past few decades, for a sympathetic but not overly-enthusiastic presentation of current neuroscientific theory, for a book that is readable enough for the non-scientist yet reliable enough for the academic professional needing to know where modern neuroscience may impact his or her field, for those just wanting to know how modern neuroscience might help them deal with themselves and the people around them--I doubt this book will be bettered until there are significant advances in the field.