What do you think?
Rate this book
The Spike: An Epic Journey Through the Brain in 2.1 Seconds
The story of a neural impulse and what it reveals about how our brains work
We see the last cookie in the box and think, can I take that? We reach a hand out. In the 2.1 seconds that this impulse travels through our brain, billions of neurons communicate with one another, sending blips of voltage through our sensory and motor regions. Neuroscientists call these blips “spikes.” Spikes enable us to do talk, eat, run, see, plan, and decide. In The Spike , Mark Humphries takes readers on the epic journey of a spike through a single, brief reaction. In vivid language, Humphries tells the story of what happens in our brain, what we know about spikes, and what we still have left to understand about them.
Drawing on decades of research in neuroscience, Humphries explores how spikes are born, how they are transmitted, and how they lead us to action. He dives into previously unanswered Why are most neurons silent? What causes neurons to fire spikes spontaneously, without input from other neurons or the outside world? Why do most spikes fail to reach any destination? Humphries presents a new vision of the brain, one where fundamental computations are carried out by spontaneous spikes that predict what will happen in the world, helping us to perceive, decide, and react quickly enough for our survival.
Traversing neuroscience’s expansive terrain, The Spike follows a single electrical response to illuminate how our extraordinary brains work.
We see the last cookie in the box and think, can I take that? We reach a hand out. In the 2.1 seconds that this impulse travels through our brain, billions of neurons communicate with one another, sending blips of voltage through our sensory and motor regions. Neuroscientists call these blips “spikes.” Spikes enable us to do talk, eat, run, see, plan, and decide. In The Spike , Mark Humphries takes readers on the epic journey of a spike through a single, brief reaction. In vivid language, Humphries tells the story of what happens in our brain, what we know about spikes, and what we still have left to understand about them.
Drawing on decades of research in neuroscience, Humphries explores how spikes are born, how they are transmitted, and how they lead us to action. He dives into previously unanswered Why are most neurons silent? What causes neurons to fire spikes spontaneously, without input from other neurons or the outside world? Why do most spikes fail to reach any destination? Humphries presents a new vision of the brain, one where fundamental computations are carried out by spontaneous spikes that predict what will happen in the world, helping us to perceive, decide, and react quickly enough for our survival.
Traversing neuroscience’s expansive terrain, The Spike follows a single electrical response to illuminate how our extraordinary brains work.
232 pages, Hardcover
Published March 9, 2021
64 people are currently reading
928 people want to read
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 30 of 31 reviews
December 19, 2025
Mark Humphries has a long-running and celebrated neuroscience blog called "The Spike" which has been reworked into this book. Despite being essentially a reworking of a blog, the book is erudite, rigorous, and, in places, likely beyond the comprehension of most lay readers. It endeavors to convey how patterns of neural firing (action potentials) become thought and behavior. Given that this is "holy grail" of neuroscience he doesn't quite pull this task off in the roughly 200 pages he uses, but it is still an impressive work.
The fundamental unit of neural communication, the spike or action potential, is simple (all-or-nothing and stereotyped) yet understanding how billions of spikes collectively give rise to perception, thought, and behaviors remains one of the hardest problems in science. The spike must encode information via timing, rate, and coordination with other spikes. Thus, Humphries posits that progress in neuroscience hinges not on the study of individual spikes but on decoding the patterns of spikes across populations of neurons. The "2.1 seconds" of the title refer to a short slice of neural activity, the decision of whether or not to take the last cookie at the office cafeteria, which serves are a framing device to explore how the brain processes information.
The shift from single neuron to populations of neurons has been a giant methodological and conceptual leap for neuroscience as classical experiments were dependent on single neurons and were heavily reductionist in approach. Neurons are noisy, variable, and context-dependent so reliable computation is a network property and must be studied at that level. Neural networks depend on the noise and variability of neurons to enable flexibility and learning. Humphries invest most of the content after establishing the basic in describing how neural networks of the brain can be modeled as dynamical systems.
Despite being a partisan for neuroscience, Humphries is candid about the limitations with current tools and methods. He points out that only a small fraction of neural activity can be sampled, these samples may not be representative, and the simplicity observed in the current data may be a mirage created by the undersampling.
All together, The Spike impressively bridges experimental neuroscience and theoretical neuroscience, which it accomplishes with system approach to the electrical physiology of neurons and their respective networks that comprise the brain. Humphries also takes the opportunity to correct common misconceptions about neural coding and reframes the brain as a dynamic system rather than a static information processor. This is all very mainstream neuroscience but it is carried off expertly. The book also studiously avoid speculation and philosophizing. This may leave many readers wanting more, but it makes for a fairly airtight work.
The fundamental unit of neural communication, the spike or action potential, is simple (all-or-nothing and stereotyped) yet understanding how billions of spikes collectively give rise to perception, thought, and behaviors remains one of the hardest problems in science. The spike must encode information via timing, rate, and coordination with other spikes. Thus, Humphries posits that progress in neuroscience hinges not on the study of individual spikes but on decoding the patterns of spikes across populations of neurons. The "2.1 seconds" of the title refer to a short slice of neural activity, the decision of whether or not to take the last cookie at the office cafeteria, which serves are a framing device to explore how the brain processes information.
The shift from single neuron to populations of neurons has been a giant methodological and conceptual leap for neuroscience as classical experiments were dependent on single neurons and were heavily reductionist in approach. Neurons are noisy, variable, and context-dependent so reliable computation is a network property and must be studied at that level. Neural networks depend on the noise and variability of neurons to enable flexibility and learning. Humphries invest most of the content after establishing the basic in describing how neural networks of the brain can be modeled as dynamical systems.
Despite being a partisan for neuroscience, Humphries is candid about the limitations with current tools and methods. He points out that only a small fraction of neural activity can be sampled, these samples may not be representative, and the simplicity observed in the current data may be a mirage created by the undersampling.
All together, The Spike impressively bridges experimental neuroscience and theoretical neuroscience, which it accomplishes with system approach to the electrical physiology of neurons and their respective networks that comprise the brain. Humphries also takes the opportunity to correct common misconceptions about neural coding and reframes the brain as a dynamic system rather than a static information processor. This is all very mainstream neuroscience but it is carried off expertly. The book also studiously avoid speculation and philosophizing. This may leave many readers wanting more, but it makes for a fairly airtight work.
March 18, 2021
Don't let the title and cover fool you, this book is secretly about cookies and navigating your workplace. Or rather the 2.1 seconds between the time you see the cookie, analyze the position of your coworkers, weigh the risks, and action your arm to grab the cookie. Wait, how does that happen anyway?
The Spike by Mark Humphries is one of the first proper monographs from a university press I have had the pleasure of reading. If you are not familiar a monograph is defined as "A scholarly piece of writing of essay or book length on a specific, often limited subject." In particular Mark takes us on a trip through the brain in The Spike, from the moment the light bouncing off said cookie contacts your eye, to it's trip through the cones, encoding spikes for the first time, taking those spikes down winding roads of axons, cloning them, tipping others to fire off in tandem, and in general creating an electrical storm that results in you grabbing said cookie.
What I enjoyed most about this book was the wit and humor Humprhies employed of the course of our story. This book could have easily been a slough by using nothing but words like "entopednucular nucleus" & "superior colliculus" but Humphries interjects at many points to make analogies for these systems and places in the brain so that the average reader can access this Gordian knot of neuroscience lingo.
Onto the subject of the book itself, I feel like I have a much better understand about how the brain works in general after reading The Spike. If you follow me on socials you know that I review many biological self help books and books on drugs so I get to hear about receptor action pretty often. However I did not know what I did not know, how do those receptors communicate between each other anyways? How does sound enter the ear to then become a hallucination at the point of the receptor? This book is helping me sketch together a more full understanding of the mind.
If this is your first foray into reading about neuroscience I think it is a fine place to start. You will learn about how your sensing organs transfer outer data into internal communications, how the brain delegates information, how it saves energy by employing parallel computing and so much more. But, if you know just a bit more than that you will be able to begin combining information that previously was filed away as separate in your own memory, similar to myself and thinking about receptors.
All in all I think this is a perfect example of a popular nonfiction book that does not sacrifice quality to appeal to the generalize audience and I would happy recommend it to anyone interested in human biology and how humans work.
The Spike by Mark Humphries is one of the first proper monographs from a university press I have had the pleasure of reading. If you are not familiar a monograph is defined as "A scholarly piece of writing of essay or book length on a specific, often limited subject." In particular Mark takes us on a trip through the brain in The Spike, from the moment the light bouncing off said cookie contacts your eye, to it's trip through the cones, encoding spikes for the first time, taking those spikes down winding roads of axons, cloning them, tipping others to fire off in tandem, and in general creating an electrical storm that results in you grabbing said cookie.
What I enjoyed most about this book was the wit and humor Humprhies employed of the course of our story. This book could have easily been a slough by using nothing but words like "entopednucular nucleus" & "superior colliculus" but Humphries interjects at many points to make analogies for these systems and places in the brain so that the average reader can access this Gordian knot of neuroscience lingo.
Onto the subject of the book itself, I feel like I have a much better understand about how the brain works in general after reading The Spike. If you follow me on socials you know that I review many biological self help books and books on drugs so I get to hear about receptor action pretty often. However I did not know what I did not know, how do those receptors communicate between each other anyways? How does sound enter the ear to then become a hallucination at the point of the receptor? This book is helping me sketch together a more full understanding of the mind.
If this is your first foray into reading about neuroscience I think it is a fine place to start. You will learn about how your sensing organs transfer outer data into internal communications, how the brain delegates information, how it saves energy by employing parallel computing and so much more. But, if you know just a bit more than that you will be able to begin combining information that previously was filed away as separate in your own memory, similar to myself and thinking about receptors.
All in all I think this is a perfect example of a popular nonfiction book that does not sacrifice quality to appeal to the generalize audience and I would happy recommend it to anyone interested in human biology and how humans work.
March 7, 2021
This book review was written for Knowing Neurons, through which I received a promotional copy of the book from the publisher. Click here to visit our site, see this review, and see our other neuroscience book reviews.
----
Recently I asked one of my faculty advisors if he would ever write a popular science book. He’s a bestselling author in his own right, having written a textbook that many consider to be an essential operating manual for human cognitive neuroscience. But as for penning a work of popular science, he denied having any interest. "I don't want to have to write a book of lies," he said resolutely.
Hot take, but I understand what he means. Crafting a book that can appeal to the broadest audience requires omitting technical details that take years of study to really grasp. Consequently, with the trickiest details smoothed down, popular science books too often end up skating over the controversies and ambiguities that mire the forefront of a scientific field.
These books claim to offer transmissions from the cutting edge, when actually the growing body of scientific knowledge looks at its extremities less like something that can cut and more like the fuzzy surface of a creeping mold. At the edge, the supposed line between true and false is really a blurry thicket of conjecture and debate, evidence and counterargument; proxy measures, simplifications, assumptions; confidence intervals, replicability concerns, and controls for long-run error. Any academic researcher will tell you this. And often they will tell you this with a grim countenance. But the task of the popular science author is to portray this thicket from a distance, so that it appears as a line – a sharp, bright line with a cutting edge. Well, the line is the lie; that’s what I understood my emphatically uninterested faculty advisor to mean.
And yet: I am not reluctant to engage with popular science. Reading books about the mysteries of outer space or about the frenetic machinations of our cells and tissues hooked me on science from a young age. And even now, after several years of graduate study in cognitive neuroscience, I still regularly turn to lighthearted books about the brain and the mind when I want to see my field with a wider angle and a softer focus.
The Spike, by Mark Humphries, is a book that I will return to often for this purpose. Professor Humphries, Chair in Computational Neuroscience at the University of Nottingham, has woven together strands of experimental results and theoretical insights to compose a book that is engrossing, excites the imagination, beautifully encapsulates contemporary neuroscience in a light and breezy package, and points the way to future discovery.
On its surface, The Spike is a story about input and output: What happens when a mote of light strikes the eye, initiating a signal that wends its way through the brain, eventually to prompt a muscle into action. As the story goes, that bit of light happens to issue forth from a cookie sitting on a desk in an office, and the effect eventually produced is a surreptitious movement to nab the tempting treat. Against the backdrop of this prosaic little scene is cast the seething, hypercomplex drama playing out inside the skull. This juxtaposition of the drab and the drastic is hilarious, and the playful tone established by this premise is buoyed throughout the text by conversational language and colorful prose. For example: Action potentials are the titular “spikes,” synapses are “gaps,” and at one point the structure of cortex is described as "a delicately layered cake, six layers in all, five layers crammed with juicy neurons, the first, top layer bereft of them.” And, in keeping the style light and conversational, the book is free of any footnotes, a mercy that I earnestly appreciated while reading.
In this breezy casual manner, The Spike tracks the tortuous path from retina to visual cortex, through object recognition and localization processes, to prefrontal cortex, through basal ganglia and motor cortex, and into the spinal cord. But just as the mundane occurrence of an office worker reaching for a cookie belies the immensity of activity unfolding in the brain, the story of a neural impulse originating in the retina and ending up at a neuromuscular junction is even itself just the surface of a much more significant story: In its essence, The Spike is an overview of modern neuroscience grappling with the profound question of how exactly the structure and activity of the brain enables it to process information. If the brain is a biological computer, how does the computer work? How do action potentials, the currency of neurons, carry information about the world outside the skull, transmute it, and utilize it? By presenting leading theories from computational neuroscience in the narrative framework of the spike’s journey, Professor Humphries tackles this daunting task brilliantly.
The Spike is a popular science book in the sense that it boils down a vast field of scientific inquiry into an entertaining tale that can be digested by a general audience. A reader would be well-served to have some educational background in biology and neuroscience, so that talk of membranes, ions, voltage, and the like don’t bog down the narrative as the bigger picture is sketched out, but the story is accessible to a broad audience of science enthusiasts. Even for its popular science credentials, the book still has plenty to offer to a seasoned neuroscience student or researcher, especially anyone who is eager to poke their head up from their work’s narrow specialization and check in with the status of contemporary neuroscience at large.
My longstanding appreciation for the popular science genre has never faltered over the years, but it has evolved. More and more, as I move along the scholastic path, I’m learning what makes for a good popular science book. The content of popular science books should balance engaging stories with the unflattering uncertainties that are the true engine of theoretical progress, and underpin bold claims with enough technical detail to make the logic sound. But first and foremost, the key objective of a popular science book is to not be boring. The Spike accomplishes all of these objectives expertly, and is one of my favorite books of popular neuroscience that I’ve ever read.
----
Recently I asked one of my faculty advisors if he would ever write a popular science book. He’s a bestselling author in his own right, having written a textbook that many consider to be an essential operating manual for human cognitive neuroscience. But as for penning a work of popular science, he denied having any interest. "I don't want to have to write a book of lies," he said resolutely.
Hot take, but I understand what he means. Crafting a book that can appeal to the broadest audience requires omitting technical details that take years of study to really grasp. Consequently, with the trickiest details smoothed down, popular science books too often end up skating over the controversies and ambiguities that mire the forefront of a scientific field.
These books claim to offer transmissions from the cutting edge, when actually the growing body of scientific knowledge looks at its extremities less like something that can cut and more like the fuzzy surface of a creeping mold. At the edge, the supposed line between true and false is really a blurry thicket of conjecture and debate, evidence and counterargument; proxy measures, simplifications, assumptions; confidence intervals, replicability concerns, and controls for long-run error. Any academic researcher will tell you this. And often they will tell you this with a grim countenance. But the task of the popular science author is to portray this thicket from a distance, so that it appears as a line – a sharp, bright line with a cutting edge. Well, the line is the lie; that’s what I understood my emphatically uninterested faculty advisor to mean.
And yet: I am not reluctant to engage with popular science. Reading books about the mysteries of outer space or about the frenetic machinations of our cells and tissues hooked me on science from a young age. And even now, after several years of graduate study in cognitive neuroscience, I still regularly turn to lighthearted books about the brain and the mind when I want to see my field with a wider angle and a softer focus.
The Spike, by Mark Humphries, is a book that I will return to often for this purpose. Professor Humphries, Chair in Computational Neuroscience at the University of Nottingham, has woven together strands of experimental results and theoretical insights to compose a book that is engrossing, excites the imagination, beautifully encapsulates contemporary neuroscience in a light and breezy package, and points the way to future discovery.
On its surface, The Spike is a story about input and output: What happens when a mote of light strikes the eye, initiating a signal that wends its way through the brain, eventually to prompt a muscle into action. As the story goes, that bit of light happens to issue forth from a cookie sitting on a desk in an office, and the effect eventually produced is a surreptitious movement to nab the tempting treat. Against the backdrop of this prosaic little scene is cast the seething, hypercomplex drama playing out inside the skull. This juxtaposition of the drab and the drastic is hilarious, and the playful tone established by this premise is buoyed throughout the text by conversational language and colorful prose. For example: Action potentials are the titular “spikes,” synapses are “gaps,” and at one point the structure of cortex is described as "a delicately layered cake, six layers in all, five layers crammed with juicy neurons, the first, top layer bereft of them.” And, in keeping the style light and conversational, the book is free of any footnotes, a mercy that I earnestly appreciated while reading.
In this breezy casual manner, The Spike tracks the tortuous path from retina to visual cortex, through object recognition and localization processes, to prefrontal cortex, through basal ganglia and motor cortex, and into the spinal cord. But just as the mundane occurrence of an office worker reaching for a cookie belies the immensity of activity unfolding in the brain, the story of a neural impulse originating in the retina and ending up at a neuromuscular junction is even itself just the surface of a much more significant story: In its essence, The Spike is an overview of modern neuroscience grappling with the profound question of how exactly the structure and activity of the brain enables it to process information. If the brain is a biological computer, how does the computer work? How do action potentials, the currency of neurons, carry information about the world outside the skull, transmute it, and utilize it? By presenting leading theories from computational neuroscience in the narrative framework of the spike’s journey, Professor Humphries tackles this daunting task brilliantly.
The Spike is a popular science book in the sense that it boils down a vast field of scientific inquiry into an entertaining tale that can be digested by a general audience. A reader would be well-served to have some educational background in biology and neuroscience, so that talk of membranes, ions, voltage, and the like don’t bog down the narrative as the bigger picture is sketched out, but the story is accessible to a broad audience of science enthusiasts. Even for its popular science credentials, the book still has plenty to offer to a seasoned neuroscience student or researcher, especially anyone who is eager to poke their head up from their work’s narrow specialization and check in with the status of contemporary neuroscience at large.
My longstanding appreciation for the popular science genre has never faltered over the years, but it has evolved. More and more, as I move along the scholastic path, I’m learning what makes for a good popular science book. The content of popular science books should balance engaging stories with the unflattering uncertainties that are the true engine of theoretical progress, and underpin bold claims with enough technical detail to make the logic sound. But first and foremost, the key objective of a popular science book is to not be boring. The Spike accomplishes all of these objectives expertly, and is one of my favorite books of popular neuroscience that I’ve ever read.
May 14, 2021
As another reviewer already made the joke of this book being about a cookie, there is nothing left for me except writing an honest review.
And this is not difficult at all.
Exceeded my expectations and then lots and lots of fantastic writing on top.
So damn good!
It surprises you even when you think you already know how good the book is by reading a few chapters.
Dense? Yes! Ever boring? No! Funny? Yes!
So what is this book about?
All the little mysteries under scientific investigation regarding information transmission via spikes in our nervous systems.
Dark neurons, synaptic failure, whether legions of spikes code the information or particular neuron spikes do, what the spontaneous activity in the brain is all about(as far as can be told rn) and how it comes into existence.
Also there is lots of neuroscience woven together in this one journey of how a person sees, decides, grabs and eats a cookie.
It serves as a great recollection of systems neuroscience/how the different areas in the brain work together.
For whom is this book?
While the first two chapters will not be new for the seasoned neuroenthusiast(Which I am not) there will most definetely be amazing drops of delicious information for anyone interested in the brain and behavior. Propably it should be known beforehand, how it is that an action potential comes into being.
Written form or audioversion?
The audiobook version will be overwhelming as the speaker is very casual about spitting out some high grade mind fuel. Great as a recap tho after reading the booklet.
So get this book and join me in admiring Mark Humphries for this precious work of cookie craving!
And this is not difficult at all.
Exceeded my expectations and then lots and lots of fantastic writing on top.
So damn good!
It surprises you even when you think you already know how good the book is by reading a few chapters.
Dense? Yes! Ever boring? No! Funny? Yes!
So what is this book about?
All the little mysteries under scientific investigation regarding information transmission via spikes in our nervous systems.
Dark neurons, synaptic failure, whether legions of spikes code the information or particular neuron spikes do, what the spontaneous activity in the brain is all about(as far as can be told rn) and how it comes into existence.
Also there is lots of neuroscience woven together in this one journey of how a person sees, decides, grabs and eats a cookie.
It serves as a great recollection of systems neuroscience/how the different areas in the brain work together.
For whom is this book?
While the first two chapters will not be new for the seasoned neuroenthusiast(Which I am not) there will most definetely be amazing drops of delicious information for anyone interested in the brain and behavior. Propably it should be known beforehand, how it is that an action potential comes into being.
Written form or audioversion?
The audiobook version will be overwhelming as the speaker is very casual about spitting out some high grade mind fuel. Great as a recap tho after reading the booklet.
So get this book and join me in admiring Mark Humphries for this precious work of cookie craving!
December 31, 2021
I read this as part of the neuroscience book club I co-run. Humphries' stated intent was to write a systems neuroscience book for a general audience. He noticed that while there were many popular science books for other subfields of neuroscience, that didn't really exist for systems neuroscience, perhaps because the core concepts often require a strong quantitative background. Humphries, in the spirit of "if you can't explain it to a five year old..." ambitiously wrote a book to rectify that.
I have a background in neuroscience, and noticed while reading the book that I was ignorant of many of the big concepts in the book, so it was really cool to learn about them. I found the dark neuron problem really interesting and our book club had a good time discussing whether 90% of cortical neurons are always dark, or if representations move around in the cortex such that at any one time 90% are not firing but it isn't a consistent set. The experimental evidence seems not yet clear enough to disambiguate this.
Similarly, I was unaware of the wide variety in failure rates of neurons (as high as 95%, as low as 0%), failure defined here as an input neuron failing to elicit a change in voltage in another neuron. It was really cool to think about this variability as actually a powerful computational tool. Synapses have to start as unreliable connections because the strengthening of a connection is how learning happens in the brain. Interestingly, noise in the brain may also serve to generalize between instances, a foundational mechanism of learning.
The concept of spontaneous spiking was perhaps the most interesting big idea in the book. Spontaneous spikes seem to play an important role in prediction. For example, in people trying to decide whether a picture is of two faces or a vase, the more spontaneous activity in the fusiform face area before seeing the picture, the more likely they are to decide it’s a face. The spontaneous spikes in these cases, may represent previous experience. Interestingly, as an animal grows older, the differences between spikes evoked from experiencing the world and spontaneous spikes decreases. This is thought to reflect greater learning about the natural world, and predicting it accurately. Information about the outside world may actually be encoded by changes in spontaneous spikes. In order to experience the world quickly, we can’t rely on neurons to generate signals from scratch each time. Experiences making tweaks to ongoing spontaneous activity is much more efficient. The idea that *spontaneous activity is you* actually gave me chills. They are your daydreams and planning, your musings. Your rich internal life is the sending and receiving of spontaneous spikes across your brain. “The most important journey for the spike then, is not from input to output, it is the eternal cycle, looping forever within the brain.” I finished this book on the heels of watching Matrix Resurrections (terrible movie btw), and enjoyed thinking about how uniquely adapted mammalian brains are to being in the Matrix, if most of our inner lives are the result of spontaneous spikes anyway with minimal input from the environment.
I also really liked Humphries focus on basic questions. He asks for example, why do neurons turn voltage into chemical transmission, only to turn it back into voltage? It's the kind of question a child might ask, but an expert would be really interested in the answer.
However, this book was really badly organized. To present this to the book club, I had to write down all my thoughts and then make an organizational frame work out of those notes myself for the summary to make any sense. Humphries even says himself that populations of neurons likely code for the functions we now assume single neurons are doing, a mistake we've made due to technical limitations in neuron recording thus far. Thus, the format of following a single spike from seeing a cookie to grabbing it was not well suited to the topic. I also got the feeling that Humphries became overwhelmed by the exponential increase in complexity after leaving the retina and the format began to seem really arbitrary and uncomprehensive. The organization was the most common complaint about the book in our book club.
Also, to state a more superficial gripe, Humphries' jokes were irritating and repetitive. He gets really stuck on this idea of neuroscientists being "bad at names" for the convention of choosing names to encode helpful attributes. For example, periaqueductal gray refers to an area of grey matter surrounding the cerebral aqueduct in the midbrain. Humphries chooses to rename this area "Peggy." Cool, that's really helpful, thanks. To showcase his prowess at naming things, he coins the phrase "Type 2 dark neurons" to refer to neurons that are pretty much the opposite of the original definition of dark neurons, a name that every member of book club said confused them for the whole book.
In short, really cool big ideas in the book. I would eagerly pick up another popular science book on systems neuroscience and I now find that field way more interesting than I did before. The organization of the book was very bad and could use a major revamp.
I have a background in neuroscience, and noticed while reading the book that I was ignorant of many of the big concepts in the book, so it was really cool to learn about them. I found the dark neuron problem really interesting and our book club had a good time discussing whether 90% of cortical neurons are always dark, or if representations move around in the cortex such that at any one time 90% are not firing but it isn't a consistent set. The experimental evidence seems not yet clear enough to disambiguate this.
Similarly, I was unaware of the wide variety in failure rates of neurons (as high as 95%, as low as 0%), failure defined here as an input neuron failing to elicit a change in voltage in another neuron. It was really cool to think about this variability as actually a powerful computational tool. Synapses have to start as unreliable connections because the strengthening of a connection is how learning happens in the brain. Interestingly, noise in the brain may also serve to generalize between instances, a foundational mechanism of learning.
The concept of spontaneous spiking was perhaps the most interesting big idea in the book. Spontaneous spikes seem to play an important role in prediction. For example, in people trying to decide whether a picture is of two faces or a vase, the more spontaneous activity in the fusiform face area before seeing the picture, the more likely they are to decide it’s a face. The spontaneous spikes in these cases, may represent previous experience. Interestingly, as an animal grows older, the differences between spikes evoked from experiencing the world and spontaneous spikes decreases. This is thought to reflect greater learning about the natural world, and predicting it accurately. Information about the outside world may actually be encoded by changes in spontaneous spikes. In order to experience the world quickly, we can’t rely on neurons to generate signals from scratch each time. Experiences making tweaks to ongoing spontaneous activity is much more efficient. The idea that *spontaneous activity is you* actually gave me chills. They are your daydreams and planning, your musings. Your rich internal life is the sending and receiving of spontaneous spikes across your brain. “The most important journey for the spike then, is not from input to output, it is the eternal cycle, looping forever within the brain.” I finished this book on the heels of watching Matrix Resurrections (terrible movie btw), and enjoyed thinking about how uniquely adapted mammalian brains are to being in the Matrix, if most of our inner lives are the result of spontaneous spikes anyway with minimal input from the environment.
I also really liked Humphries focus on basic questions. He asks for example, why do neurons turn voltage into chemical transmission, only to turn it back into voltage? It's the kind of question a child might ask, but an expert would be really interested in the answer.
However, this book was really badly organized. To present this to the book club, I had to write down all my thoughts and then make an organizational frame work out of those notes myself for the summary to make any sense. Humphries even says himself that populations of neurons likely code for the functions we now assume single neurons are doing, a mistake we've made due to technical limitations in neuron recording thus far. Thus, the format of following a single spike from seeing a cookie to grabbing it was not well suited to the topic. I also got the feeling that Humphries became overwhelmed by the exponential increase in complexity after leaving the retina and the format began to seem really arbitrary and uncomprehensive. The organization was the most common complaint about the book in our book club.
Also, to state a more superficial gripe, Humphries' jokes were irritating and repetitive. He gets really stuck on this idea of neuroscientists being "bad at names" for the convention of choosing names to encode helpful attributes. For example, periaqueductal gray refers to an area of grey matter surrounding the cerebral aqueduct in the midbrain. Humphries chooses to rename this area "Peggy." Cool, that's really helpful, thanks. To showcase his prowess at naming things, he coins the phrase "Type 2 dark neurons" to refer to neurons that are pretty much the opposite of the original definition of dark neurons, a name that every member of book club said confused them for the whole book.
In short, really cool big ideas in the book. I would eagerly pick up another popular science book on systems neuroscience and I now find that field way more interesting than I did before. The organization of the book was very bad and could use a major revamp.
July 7, 2021
3,5*
May 15, 2021
This is a very enjoyable tour of the current state of knowledge in neuroscience as of 2021.
Instead of focusing on the different areas of the brain it attempts to describe what we know about how neurons spike.
A few of the things that I picked up:
(1) The AVERAGE rate of spiking for cortical neurons is 1 spike/second.
Thus within a human lifetime there are roughly 34 billion billion (34 * 10^18) cortical neuronal spikes (assuming 17 billion cortical neurons and a lifespan of 70 years). This constitutes all of a person's perceptions, thoughts, emotions and actions.
(2) The existence of "dark neurons"
(3) The existence of "spontaneously firing neurons"
But what struck me is how many disciplines studying the brain at this level involves:
(1) Physics - this scale is small enough that even quantum effects may be involved (although this is speculation).
(2) Chemistry - Lots of potassium and sodium ions and neurotransmitters and other things chemically interacting.
(3) Computer Science! - My favorite- Obviously many kinds of computation are being performed, but we can't quite figure out the algorithm. How does the brain accurately estimate the distance to an object for example? It's not just object recognition or memory recall, there are some fascinating and sophisticated algorithms being used.
(4) Philosophy - How does inanimate matter generate perception? And consciousness.
(5) Psychology/Psychiatry - Some mental illnesses have been directly linked to inadequate levels of specific neurotransmitters in the brain.
(6) Medicine - Diseases like Alzheimer's or Parkinson's are caused by brain malfunctions we don't understand.
But the most exciting thing is that it seems a lot of progress is being made as far as getting more and more precise brain data using new measuring instruments and technologies.
I wonder if we'll understand in my lifetime even something relatively simple like how we're able to hit a baseball or understand a single word on a neuron by neuron level.
Instead of focusing on the different areas of the brain it attempts to describe what we know about how neurons spike.
A few of the things that I picked up:
(1) The AVERAGE rate of spiking for cortical neurons is 1 spike/second.
Thus within a human lifetime there are roughly 34 billion billion (34 * 10^18) cortical neuronal spikes (assuming 17 billion cortical neurons and a lifespan of 70 years). This constitutes all of a person's perceptions, thoughts, emotions and actions.
(2) The existence of "dark neurons"
(3) The existence of "spontaneously firing neurons"
But what struck me is how many disciplines studying the brain at this level involves:
(1) Physics - this scale is small enough that even quantum effects may be involved (although this is speculation).
(2) Chemistry - Lots of potassium and sodium ions and neurotransmitters and other things chemically interacting.
(3) Computer Science! - My favorite- Obviously many kinds of computation are being performed, but we can't quite figure out the algorithm. How does the brain accurately estimate the distance to an object for example? It's not just object recognition or memory recall, there are some fascinating and sophisticated algorithms being used.
(4) Philosophy - How does inanimate matter generate perception? And consciousness.
(5) Psychology/Psychiatry - Some mental illnesses have been directly linked to inadequate levels of specific neurotransmitters in the brain.
(6) Medicine - Diseases like Alzheimer's or Parkinson's are caused by brain malfunctions we don't understand.
But the most exciting thing is that it seems a lot of progress is being made as far as getting more and more precise brain data using new measuring instruments and technologies.
I wonder if we'll understand in my lifetime even something relatively simple like how we're able to hit a baseball or understand a single word on a neuron by neuron level.
April 18, 2022
I was excited to see this on the bookshop shelf. While there are many popular science books on the brain, not many focus on the remarkable unit of neural information transfer. Having briefly studied this myself decades ago (before going on to an unrelated career), I looked forward to finding out about the current state of thinking on, say, the temporal coding of information in single spikes. Well, we never quite get to that in this short book, but the author does provide a well balanced overview. In the process he introduces a number of ideas that I was totally unaware of and, I am ready to bet, had not been discussed before in a popular science book.
However, while I found much of the book’s content fascinating I have some issues with the form, specifically with the writing style. The connectivity and dynamics of neural system and how they relate to functionality are difficult to describe in words, and I would argue that they require sober and disciplined writing as well as ruthless prioritisation of clarity over any attempted stylistic effect. Unfortunately, for much of its length this book goes all out in the opposite direction. The jocular, matey, wisecracking tone, at times attempting to cram multiple witticisms into each sentence, didn’t really work for me, and eventually I thought it just got in the way of understanding what’s being discussed. I often felt distracted by convoluted paragraphs made up mostly of mixed metaphors and clichés, before I recognised, several sentences in, a familiar concept. I understand this is all meant to make the subject more accessible, but for my part I confess I found the prose harder to read than a textbook.
However, while I found much of the book’s content fascinating I have some issues with the form, specifically with the writing style. The connectivity and dynamics of neural system and how they relate to functionality are difficult to describe in words, and I would argue that they require sober and disciplined writing as well as ruthless prioritisation of clarity over any attempted stylistic effect. Unfortunately, for much of its length this book goes all out in the opposite direction. The jocular, matey, wisecracking tone, at times attempting to cram multiple witticisms into each sentence, didn’t really work for me, and eventually I thought it just got in the way of understanding what’s being discussed. I often felt distracted by convoluted paragraphs made up mostly of mixed metaphors and clichés, before I recognised, several sentences in, a familiar concept. I understand this is all meant to make the subject more accessible, but for my part I confess I found the prose harder to read than a textbook.
July 11, 2024
"The Spike: An Epic Journey Through the Brain in 2.1 Seconds" by Mark Humphries is a captivating exploration of neuroscience for the curious layperson. Humphries takes readers on a fascinating journey through the intricate workings of our nervous system, framed around a simple impulse to "get the last donut."
As a neuroscience enthusiast, I was impressed by Humphries's ability to explain complex concepts in an engaging and accessible manner. His vivid descriptions of neural pathways and the speed at which information travels through our bodies are particularly memorable. For instance, his explanation of how a single neuron can process information from up to 10,000 other neurons simultaneously left me in awe of our brain's complexity.
Humphries strikes an excellent balance between providing detailed scientific information and maintaining a fun, narrative approach. He not only illuminates the incredible design and structure of our nervous system but also humbly acknowledges the vast areas of neuroscience that remain unknown.
While the book is generally accessible, readers with no prior exposure to biology or neuroscience might find some sections challenging. However, Humphries's clear writing style and use of analogies help bridge this gap.
For anyone interested in understanding more about how our brains and bodies work, "The Spike" is highly recommended. It will leave you with a renewed appreciation for the marvel that is the human nervous system and the realization that the more we learn about our brains, the more astounding they become.
As a neuroscience enthusiast, I was impressed by Humphries's ability to explain complex concepts in an engaging and accessible manner. His vivid descriptions of neural pathways and the speed at which information travels through our bodies are particularly memorable. For instance, his explanation of how a single neuron can process information from up to 10,000 other neurons simultaneously left me in awe of our brain's complexity.
Humphries strikes an excellent balance between providing detailed scientific information and maintaining a fun, narrative approach. He not only illuminates the incredible design and structure of our nervous system but also humbly acknowledges the vast areas of neuroscience that remain unknown.
While the book is generally accessible, readers with no prior exposure to biology or neuroscience might find some sections challenging. However, Humphries's clear writing style and use of analogies help bridge this gap.
For anyone interested in understanding more about how our brains and bodies work, "The Spike" is highly recommended. It will leave you with a renewed appreciation for the marvel that is the human nervous system and the realization that the more we learn about our brains, the more astounding they become.
December 23, 2022
I think this guy wanted to be a novelist but got into the wrong field. He keeps trying to be funny and put the reader on a roller coaster with the hope of making the content more interesting or whatever but ends up doing the opposite. Just when you start getting something and feel like things are going somewhere, there's that weird roller coaster thing again, which makes no sense at all and just makes it difficult to grasp the material. He could've explained everything in a simple manner, which would've been interesting in and of itself, but NOOOO he gotta write a fantasy novel yo!
Okay, maybe I'm being too harsh, but I just wanted to say that there was something off about the way the content was presented, and his way of describing where we are in the brain is definitely really bad. Why did I give it 4 stars, then? Because I did learn quite a few new things about the inner workings of the brain in terms of spikes. And I'd definitely recommend the book but just don't feel discouraged if you don't get some of the things because it's not you; the writing is bad in this one at many places throughout the book. The content is very good, though.
Okay, maybe I'm being too harsh, but I just wanted to say that there was something off about the way the content was presented, and his way of describing where we are in the brain is definitely really bad. Why did I give it 4 stars, then? Because I did learn quite a few new things about the inner workings of the brain in terms of spikes. And I'd definitely recommend the book but just don't feel discouraged if you don't get some of the things because it's not you; the writing is bad in this one at many places throughout the book. The content is very good, though.
November 5, 2023
I thought that this was an excellent book. The author has cleverly used an entertaining situation to walk us through some of the known aspects of brain function at the neuron level. Most importantly, he has clearly highlighted the many other aspects we know nothing, or next to nothing, about. So the reader won't finish this book thinking that, just because we can describe a good deal about a stimulus-response sequence, we actually understand brain function. Although the author also offers a plausible unifying account of what the brain does (i.e., prediction), he does not pretend this is the answer to everything, and certainly not everything human. Here's true expertise disseminated at a comprehensible but not dumbed-down level. I found it amazing that so much solid information is condensed in a rather short book that never feels packed or too dense. I imagine that readers with zero previous knowledge of the brain will not understand every detail, but then these readers would probably not prefer a 700-page book where everything is explained from scratch, even if written by Humphries. Highly recommended.
September 27, 2021
Mark Humphries has a knack for simplifying the complex. I am no stranger to the field of neuroscience, but Systems Neuroscience is a brave new world for me. Humphries undertakes the monumental task of explaining how spikes in the brain allow us to perform a single action - eat a cookie. By placing us atop a spike, we zip through different parts of the brain, experiencing everything a spike experiences (or that our limited knowledge tells us the spike undergoes).
Given how complex the brain and its working are, some parts were understandably difficult to comprehend and retain. Such incomprehension may also be compounded by the fact that I listened to the audiobook. Perhaps reading the book, going back and forth between concepts, and referring to accompanying illustrations may have made things easier.
I did appreciate the author’s insights on what we do not yet know about the brain, given the limitations of current technology. If we ever solve the problem of the neuroscience of consciousness, I would want to learn all about it from Mark Humphries.
Given how complex the brain and its working are, some parts were understandably difficult to comprehend and retain. Such incomprehension may also be compounded by the fact that I listened to the audiobook. Perhaps reading the book, going back and forth between concepts, and referring to accompanying illustrations may have made things easier.
I did appreciate the author’s insights on what we do not yet know about the brain, given the limitations of current technology. If we ever solve the problem of the neuroscience of consciousness, I would want to learn all about it from Mark Humphries.
February 13, 2022
Without a background in neuroscience, I read the book with quite a bit of googling along the way. It is not an easy read for a beginner but it provides me with significant knowledge and understanding on how our neurons serve various purposes including the different ways they interact and roles they play. Though the author used only the act of seeing a cookie via the visual neurons and ultimately grabs it with movements directed by motor neurons, which involved only a limited kinds of neuron types, but this journey of "spikes" that transverse across the neuro system brought in useful explanations of very interesting knowledge of the subject.
February 1, 2024
I’ve long been fascinated by how our brains work. I heard this author interviewed a few months ago on the BrainScience podcast and decided I wanted to learn more from this scientist. This book absolutely met my expectations for a book written for a general audience. I thought the analogy around which he structured his book - will I take the cookie out of the box on the desk - was ingenious. He took us on a journey through the brain on the “what” highway and on the “do” highway. He explained current scientific knowledge, presented some theoretical speculations and pondered the future directions of the science. I enjoyed the journey and learned a lot.
May 19, 2025
3.5 (3 if i weren't already incredibly interested in the topic)
It's a very interesting book and Mark Humphries is a distinguished researcher in the field. However, even though I'm in a very similar field, I found the way he attempts to explain everything - via flowery prose and the overarching story of fetching a cookie - to be utterly confusing, harming the clarity of the book more than anything.
My advice for anyone reading this: Try to ignore or skim over the metaphors and story elements and just try to follow the core elements. It does contain worthwhile information and a nice bibliography for further research.
It's a very interesting book and Mark Humphries is a distinguished researcher in the field. However, even though I'm in a very similar field, I found the way he attempts to explain everything - via flowery prose and the overarching story of fetching a cookie - to be utterly confusing, harming the clarity of the book more than anything.
My advice for anyone reading this: Try to ignore or skim over the metaphors and story elements and just try to follow the core elements. It does contain worthwhile information and a nice bibliography for further research.
January 28, 2022
A nice deep dive into the brain following the spikes -- the ever present electric signal in our brain.
My feeling: we still have so much to know/study about the brain. It's complex and intriguing.
The discussion about spikes in response to the outside world vs. spontaneous spikes is my favorite (the last chapter).
From several books I read, it seems well established in multiple disciplines that brain is a prediction machine. And the ability of building models and making predictions may well be what "intelligence" entails.
My feeling: we still have so much to know/study about the brain. It's complex and intriguing.
The discussion about spikes in response to the outside world vs. spontaneous spikes is my favorite (the last chapter).
From several books I read, it seems well established in multiple disciplines that brain is a prediction machine. And the ability of building models and making predictions may well be what "intelligence" entails.
September 19, 2021
Buy a paper copy and bring a highlighter, a pen, and a notebook. It's a slow read but worth it. So much to learn.
I would ding a fraction of a star for writing style. It aims to be a bit more conversational which resulted in long, complex sentences. Simpler exposition would have worked better given the technical content density.
I would ding a fraction of a star for writing style. It aims to be a bit more conversational which resulted in long, complex sentences. Simpler exposition would have worked better given the technical content density.
June 2, 2023
I really wanted to love this book but I ended up just trudging through it. My job is to literally record spikes in the brain for a living so I mistakenly thought I’d like this. I appreciate the author’s attempt to make it more engaging but inserting quirky anecdotal bits here and there but this still was a miss for me.
September 2, 2021
Humphries is a masterful writer with a deep knowledge of systems neuroscience. This is a fantastic book that connects history to the boundaries of our knowledge about the brain. I loved the concept of travelling along spikes, a lot like the good old 'magic schoolbus' shows I watched as a kid.
March 7, 2023
What the cover doesn't tell you is that this is really a pop-sci introduction to systems neuroscience, and that's good. Systems neuro has needed a popular book like this for at least a decade, and this one is pretty good.
March 17, 2024
This was... all right. Don't get me wrong, the book per se is good (and the content is sufficiently brainy (pun intended) and available to the average Bob who wants to know more about spikes - even though some basic neuroscience knowledge will help to go through), but I found it almost impossible to keep up with 100% of the content. I enjoyed the overview of the scientific findings and the real-life examples provided, but I still missed a whole lot of information (no matter how much I hit that 5-seconds rewind button). I think the audio format is not ideal for this book (and the narration was not very becoming for the content either). Anyway, I would still recommend this book, but probably in print - and I leave open the possibility of revisiting it in print or as an e-book myself in the future.
December 25, 2024
I have had a chance to read The Spike, quite a few times...
It helped me establish context for the significance of neural activity and its implications on perception, decision-making and memory. Useful for people like me, who wish to integrate experimental brain data with computational models.
It helped me establish context for the significance of neural activity and its implications on perception, decision-making and memory. Useful for people like me, who wish to integrate experimental brain data with computational models.
February 4, 2025
A concise yet complete introduction to the functioning of the brain. From cell function (Hodgkin Huxley) to learning (hi Kandel?), I would recommend this book to anyone who has an interest in understanding how any form of life with a nervous system works!
March 28, 2021
Very easy to read yet thorough survey of contemporary neuroscience. Not a textbook or really a microhistory, but more correct and intellectually humble than most pop-sci writers like Malcolm Gladwell.
Left me craving cookies.
Left me craving cookies.
April 25, 2021
its cool to see how solutions to these problems evolve. just predict whats going to happen and update it instead of waiting for the input
June 6, 2021
Very well-written book about a very interesting topic I knew nothing about. Can recommend! :)
July 14, 2021
Complex and interesting and informational. Love the premise.
April 10, 2023
Great intro and coda, the in-between part is confusing for unprepared
May 22, 2025
2.5⭐️
unremarkable
unremarkable
January 21, 2025
Книга сама по себе прекрасна — доступно объясняется работа нейронов и устройство мозга с подробностями, которые я раньше встречала только в учебниках. Одна беда — перевод. Он настолько буквальный, что стилистические приемы, которые в оригинале наверняка облегчают восприятие, в русской версии делают текст совершенно нечитаемым. Если очень надо, то продраться, конечно, можно, но делать это, прямо скажем, нелегко.
Displaying 1 - 30 of 31 reviews