Emanating from the Harvard seminar entitled The Amazing Brain, this book begins with the general organization of the brain, then how these collections of cells talk to each other, and then moves on to how the various aspects of brain function come together to form our conscious experience, our minds.

Hence the title is followed in chapter one with discussions on the unique cellular structure of the brain, and how it develops. Moving on to chapter two, how the brain signals via the mechanisms of neurotransmission at the synaptic level are elucidated, as neurons have a unique (and new findings emerge all the time) method of communication. The carriers of such information, as with the endocrine system of the body, are the neurotransmitters, the big players in neuromodulation including serotonin, dopamine, the neuropeptides and other chemical messengers, as well as those playing in two extreme conditions, Parkinson’s and Schizophrenia as examples.

Chapter four refers us to the world we can sense, via mechanoreceptors such as touch and hearing (hair cells and audition), the secondary receptors of olfaction and vision, and the like.

Part two, as suggested above, looks at the expression of these elements, namely human behaviours as developed from our invertebrate predecessors in evolution, with the usual characters illuminated, namely Horseshoe Crabs, Squid axons, Sea Snail, all the elements of our micro-systems open to study, as for instance Kandel did to illuminate on long-term potentiation of memory and thus win a shared Nobel Prize. However, we are none of these animals in truth, or perhaps represent wider systems of these elements put together, and so chapter 6 comes around to our brains, or at least those of vertebrates. This covers the major elements of the CNS, the spinal cord, brain, medulla, pons, hypothalamus,  cerebellum, thalamus, basal ganglia and overall cerebral cortex.

Vision is always a complex mechanism, and two chapters that follow deal with vision as a window into the brain’s operation, and how we perceive the end product of vision.  The maturing brain, enveloped still in much mystery, provides fertile ground for axons buzzing around in organogenesis parades to find their way to becoming parvalbumin cells or doing something else finally contributory to the mature brain, and chapter 9 covers how early and later neuroplasticity is scaffolded. Given the primacy of language in primates, and uniquely so, the next chapter covers how even birdsong relies on promoting and growing brain pathways in order to communicate, an essential element in competing with other species and unshackling ourselves from the forces of the universe and in particular, the Darwinian pressures that we have had to overcome to thrive, and adapt.

Mentioning Kandel above, we are back with memory in the next chapter (11) which covers how we not only encode information but have it available for later recall in more or less reliable and useful ways, if not perfectly one to one reality as we experienced it.  Whilst all animals have physical emotions, we are more likely to have feelings of appreciation for what happens than other vertebrates and probably primates too.  Certainly, we can act on these and assert rationality using the areas expanded on here: amygdala, hypothalamus, the ANS, and orbitofrontal cortex, and both reinforcing behaviours and aforementioned rationality as a result of the collaboration of these areas. Hard to find the insula here though: the instrument of disgust not making much waves.

As promised, and in the most anticipated chapter given modern discourse on the subject, the final chapter addresses consciousness as a phenomenon in sleep, dreaming, and most importantly the future, including the promise and threat of Artificial Intelligence.

The initial discussions address the issue of growth and ageing, set as questions the author intends to answer. Some are puzzles however that he cannot, such as why the brain has few stem cells, usually hippocampal, but why the cells they create don’t last long. Or why glial cells can proliferate, leading to a risk of dysfunctional growth such as a tumour. Or why we have increased our lifespan in managing health, but that the maximum lifespan is limited by the brain’s final decline, inevitably, by 80 or so, with the 122 year old maximum lived by Jeanne Calment, an anomaly, and not replicated since her death in 1997.  Studying the maturity of the brain, and such oddities as Alzheimer’s and the brain’s often territorial response to injury, less or more depending on where the damage occurred, the development of the brain from conception is a fascinating part of understanding the brain as an evolved set of skin cells.

Discussions of basic neuronal function, as he promises in the title, include illumination on the nature of electrical discharge, and how this relates let’s say to lethal injection via K+ toxicity. Action potentials are explained alongside the other aspects of transmission, showing how they move at 100-200 miles an hour without losing amplitude, in contrast to other receptive and synaptic potentials. Using Myasthenia Gravis as an example, he leads us on to understand the function of synapses, and then the neuromodulation of transmission at that level.

No basic book would be complete without the ubiquitous diagram of the brain, showing the major divisions, you know, frontal, temporal, occipital, parietal: except this is not your usual basic book. The explanations and the setup of the way this book operates to convey its knowledge are around function, rather than architectonic divisions. Comparisons here between the actions of curare versus atropine for instance, or nicotine and muscarine, a difference in targets of neuromodulation rather than just saying they affect the actions of acetylcholine, make just this point: structure is not necessarily function in the brain, and Dowling is setting out a methodology to understanding how the brain operates, not what it might look like to a gross anatomist. This approach leads to complex discussions and explanations that take the book beyond being a basic introduction to neuronal functioning.

I am sure however that Dowling’s passing mention of psychotherapy at the end of chapter 3, with some perceived veiled contempt while lauding the value of medication, will anger most psychotherapists with his comparison to placebo effects and little reference to the preponderance of psychotherapy’s evidence base pointing to higher success rates than medication in depression, if not in more seriously debilitating conditions such as Schizophrenia or Bipolar Mood Disorder.  Nevertheless, he does make the point that most psychiatrists today “view psychotherapy as an essential adjunct of drug therapy”, a comment which probably will not ease the ire of my colleagues to his passing comments.  It is his only reference to psychotherapy and its effect on the brain in the entire book.  A challenge to his apparent flippant explanation about placebo vs real neurochemical changes might be seen in the documented brain changes elicited let’s say by EMDR and Somatic Psychology based therapies in PTSD (see https://metapsychology.mentalhelp.net/poc/view_doc.php?type=book&id=8238&cn=396) or by the M.I.R.R.O.R approach in pain (see http://metapsychology.mentalhelp.net/poc/view_doc.php?type=book&id=7547&cn=396 ).

His apparent diminishing of psychotherapy as a brain-based science is somewhat evidenced by his neglect to mention, in terms of understanding the brain, the contribution of the applied cognitive science referred to as neuropsychology. There is no mention of this discipline in any part of the book, including the chapters on understanding cognition. However, all of this neglect does not detract from the value of the book, as he is concerned clearly with the cellular-behavioural-cognitive side of science, without discussing the agencies that work with altering behaviour or cognition from a non-medical or non-neurological basis. This is both the strength and the weakness of the book, but it is written from Dowling’s perspective according to his behavioural neurology proclivities and purpose.

So, do we buy such a book for our libraries and why? If you have a distinct need to understand the way cells have evolved for a behavioural purpose, and how this then provides for the various aspects of our cognition as described above, then this book does it better than most. Read other more basic books first if you are new to the field, and if you are well established in this field, probably use it only as a refresher. As with mobile apps for instance, I find more and more students are reading and using more singular and specialized sources of information, for instance Barrett’s Beyond the Brain (http://metapsychology.mentalhelp.net/poc/view_doc.php?type=book&id=6258 ) or Wehrenberg and Prinz’s The Anxious Brain (http://metapsychology.mentalhelp.net/poc/view_doc.php?type=book&id=3771), but as a more wide application source, Dowling’s book will more than suffice.

 

© 2019 Roy Sugarman

 

Roy Sugarman PhD

Director of Applied Neuroscience

Performance Innovation Team, Team EXOS USA.