What do you think?
Rate this book
On the Origin of the Human Mind
The origin of the human mind remains one of the greatest mysteries of all times. The last 150 years since Charles Darwin proposed that species evolve under the influence of natural selection have been marked by great discoveries. However, the discussion of the evolution of the human intellect and specific forces that shaped the underlying brain evolution is as vigorous today as it was in Darwin's times. Using his background in neuroscience, the author offers an elegant, parsimonious theory of the evolution of the human mind and suggests experiments that could be done to test, refute, or validate the hypothesis. The basis of the theory is a simple, yet fundamental what happens neurologically when two objects, never before seen together (say, an apple on top of a whale), are imagined together for the first time. The scientific consensus is that a familiar object, such as an apple or a whale, is represented in the brain by thousands of neurons dispersed throughout the posterior cortex. When one sees or recalls such an object, the neurons of that object’s neuronal ensemble tend to activate into synchronous resonant activity. The neuronal ensemble binding mechanism, based on the Hebbian principle “neurons that fire together, wire together,” came to be known as the binding-by-synchrony hypothesis. However, while the Hebbian principle explains how we perceive a familiar object, it does not explain the infinite number of novel objects that humans can voluntarily imagine. The neuronal ensembles encoding those objects cannot jump into spontaneous synchronized activity on their own since the parts forming those novel images have never been seen together. The author argues that to account for imagination, the binding-by-synchrony hypothesis would need to be extended to include the phenomenon of mental synthesis whereby the brain actively and intentionally synchronizes independent neuronal ensembles into one morphed image. Thus, the apple neuronal ensemble is synchronized with the whale neuronal ensemble, and the two disparate objects are perceived together. The synchronization mechanism of mental synthesis is likely responsible for many imaginative and creative traits that scientists have recognized as being uniquely human, despite not having a precise neurological understanding of the process. How did humans acquire mental synthesis? As of 100,000 years ago, hominins had already evolved both a greater control of perception by the prefrontal cortex and a nearly modern speech-production apparatus. However the connections between the prefrontal cortex and the posterior cortex remained asynchronous; the prefrontal cortex was unable to synchronize independent neuronal ensembles, speech remained finite and one word was only able to communicate one image. At that time, a single mutation delayed the ontogenetic development of the prefrontal cortex and permitted the newly invented syntactic speech to train the synchronous connections between the prefrontal cortex and the posterior cortex. This allowed the acquisition of mental synthesis and propelled humans to behavioral modernity. These behaviorally modern humans excelled at performing mental simulations, which resulted in the dramatic acceleration of technological progress; the human population exploded and humans quickly settled most habitable areas of the planet. Armed with the ability to mentally simulate any plan and then to communicate it to their companions, humans rapidly became the dominant species.
441 pages, Kindle Edition
Published January 27, 2019
2 people are currently reading
11 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 - 2 of 2 reviews
February 5, 2021
[I read this a year ago, but it was kind of tied up in a contest until I got permission to post it here]
About 60,000 years ago, something fundamental seems to have shifted in the human mind. Before that point, you have artifacts-- stone spear points, notches on antlers, burial of the dead-- but very little progress or invention. Early Homo Sapiens was better at making spear points than Homo Neandertalensis, who was better than Homo Erectus, but in each case the shift came with the evolution of the species, and then stayed unchanged for tens of thousands of years. But after this point in time, everything changes. People spread quickly into every part of the globe, including places only reachable by boat. Artwork appears everywhere: creative, imaginative, fantastic. New tools of every kind begin to appear. New ways of organizing society pop up. People are able to organize into larger and larger groups. We either woke up, or we first began to dream.
So what changed? Looking at skeletons, there is no difference between members of our species before and after the change. We already had the ability to speak, to control our hands finely, to walk upright, to craft spears, to communicate to others. What must have changed is some more subtle evolution in how the brain is organized.
Until I read Sean Carroll's Endless Forms Most Beautiful, I didn't understand that evolution mainly works its changes to the body by modifying the timing and extent of developmental processes. A giraffe grows longer legs because a mutation or genetic recombination causes the "keep growing" signals to persist a little longer; and its longer legs enable it to reach more leaves and cover more distance in each step, so it is able to pass on those genes which control how long that development process persists. Vyshedskiy proposes that something similar happened to the development of one part of the prefrontal cortex. The juvenile period, where those neurons are able to grow and adapt, lasted a little longer, long enough that individuals would have already had time to learn a large vocabulary when a myelination process took place, allowing these controlling neural signals to reach parts of the brain already associated with memories. The growth of the prefrontal cortex enabled what Vyshedskiy calls "mental synthesis." It is the process of bringing into alignment the sychronous neural firing of one memory with the firing of another memory to form a new concept that is a combination of both.
This change, he claims, made all the difference. Before, it was possible to learn hundreds or thousands of words and associated concepts. But with the ability to recombine concepts to create new ones, people gained the ability to form an unlimited number of new propositions. Before the change, people were very good at dealing with situations that had happened before, because they had excellent memories and were able to learn the skills of their parents through direct observation. But after the change, people were able to imagine new situations that had never occurred. They could invent new tools (like needles with holes for thread) and new ways of hunting (like using long, narrowing V's made of stone walls to chase game into) and communicate these complex ideas without direct demonstration to others who had the ability to understand from only hearing something described.
The ability to use prepositions (over, under, next to), recursive grammar, and other features of human language missing from all animal languages seems to be associated with the proper development of this part of the prefrontal cortex in the right kind of environment. When children grow up past the age of six without being exposed to language with these features, they are never able to learn them-- it is a permanent disability. However, when a group of children invent a language without being exposed to other languages (as has happened several times with communities of deaf children, for instance) it includes these features. It seems that whenever you have a community of people who want to communicate, they will spontaneously invent language in its full richness. But without that, the children are not only unable to learn key features of language, their ability to perform many other skills that require imagination are also impaired. They can't solve problems they haven't already seen solved. They can't understand the difference between the idea of a snake biting a dog or a dog biting a snake: they will always tend to confuse the two, because their brain is just creating a kind of stew of the idea of a dog, the idea of a snake, and the idea of biting, rather than creating the idea of a snake biting a dog or vice versa.
His theory includes a detailed model of how this process works in the brain. When they descended from the trees onto the savannah, people needed to be better at putting together visual clues to the presence of predators into the notion of what kind of predator they were facing. So over millenia, the visual system devloped the ability to entertain hypotheses and combine ideas by changing the firing patterns of two disconnected ideas to bring them in synch and turn them into one idea. This was able to occur due to changes in the myelination of long neural connections, which slowed down or sped up the rate at which signals traveled in order to bring them in synch. This ability to form new concepts visually would extend to the ability to form new concepts linguistically, to talk about not just a tree and a bear, but a bear in a tree.
So if you have to have a community for language to develop, but it only occurs due to a mutation, how could language ever have occurred? Vyshedskiy imagines a very specific event happening in one family: an unusual pair of identical twins are born. They are slow to develop: they don't avoid danger at the age of two like the other children. But they invent their own way of communicating between themselves, and as they get older begin to lead the community to do things that have never been done before. They are succcessful, the tribe prospers, and within a few generations the genes have spread throughout the population.
It's a beautiful theory, incorporating evolutionary theory, neuroscience, child development, art history, and many other threads. Vyshedskiy provides a long list of predictions and ways his theory could be falsified. This is as solid science as has ever been done when dealing with these kinds of questions.
Still, I have my doubts. Here are three issues that he didn't discuss which pose difficulties for the theory:
1. What about aphantasia? Vyshedskiy spends a lot of the book talking about the development of the primate visual system, because he sees mental synthesis as happening in the visual system. It is, quite literally, imagination: the ability to form a mental image of something one has never seen by combining things one has seen. But some people completely lack this imagination ability, yet are able to perform without difficulty in everyday life. He presents a list of six questions that he claims cannot be solved without the ability to visualize something you've never seen:
"Question 1. Mary is taller than Julia. Jennifer is taller than Mary. Therefore, Julia is the shortest girl. Answer: True / False
Question 2. A round wall clock that has been rotated until it is hanging upside down will have a minute hand that points to your right when it is two forty. Answer: True / False
Question 3. If the word, “BOM,” is written under the word, “PRY,” and the word, “KOK,” is written under “BOM,” then the word, “POK,” is formed diagonally. Answer: True / False
Question 4. Six identical triangles can be formed by drawing two straight lines through an octagon’s center point. Answer: True / False
Question 5. If a doughnut shaped house has two doors to the outside and three doors to the inner courtyard, then it’s possible to end up back at your starting place by walking through all five doors of the house without ever walking through the same door twice. Answer: True / False
Question 6. The angle formed by the two hands of a clock is larger than 90 degrees when the time is 6:20. Answer: True / False"
I posed these questions to an acquaintance with aphantasia, and he solved all of the problems using logical reasoning:
"True. It's just a logical puzzle. No visualization needed. Consider replacing height with age.
True. It's just math. From the top, 40 minutes is about 270 degrees. Rotate 180 degrees and it's 90 degrees. 90 degrees is left.
True. Order all 3 words. Then take the first letter of the first word, the second letter of the second word, and the third letter of the third word. POK.
False. Dividing a convex polygon with a line creates at most 2 polygons. Dividing it with 2 lines creates at most 4 polygons. There can't be 6 triangles if there are only 4 polygons.
False. Again, it's purely logical. You can't go back to the start by crossing an odd number of times (3 inner doors). It's like asking if flipping a switch 3 times will turn it back to its initial state.
True. Two hands of a clock always form 2 angles whose total is 360. Hence one of them has to be greater than 90 degrees. From the top, 6 hours is 180 degrees and 20 minutes is a bit over 90 degrees (let's say 91). The angles would be 180-91 (89) and 91-180 (271). These questions require no visualization, and I'm surprised people without aphantasia would feel the need to visualize them."
While I solved them using visuaization, if I had to program a computer to solve them, I would have used the techniques my friend described in order to encode them in a way the computer could solve. I don't feel this is a knock-down argument, though. Vyshedskiy makes it very clear that he is talking about an ability that underlies both visual imagination AND language. So if my friend can solve them through language and math, he could still be using this ability in some way, creating results available to other parts of his brain, but somehow not reaching the parts associated with conscious perception.
2. What about less extreme creativity? One example Vyshedskiy gives of recombination is an early sculpture of a man with a lions' head. This is clearly a result of imagination, in no uncertain terms. But other situations , much less dramatic, also seem to involve conceptual combination. Suppose a young fox finds itself in a kind of field it has never seen before, covered with cold, white stuff. It plays in the field a while, getting a sense for how the snow behaves. Now it sees a young rabbit in the snow. It has chased rabbits before, but never in the snow. In order to chase the rabbit, it needs to somehow combine the ideas of "chasing rabbit" with "running through snow." Just because this is a more commonplace occurance, doesn't mean that the same kind of thing, combination of ideas, hasn't taken place. Vyshedskiy tries to head this off in specific cases, showing that what seems to be creative thought in animal experiments could actually be a result of instincts and learning from experience, but it isn't convincing in general. I think there would need to be a lot more experiements with animal creativity and problem solving before we could really delineate what they can and can't do.
3. What about Machine Learning neural language models? I've been working for the last few years with neural network language models trained on vast text corpora. The most recent of these can do some pretty incredible things. For example, given a prompt that puts some popular fictional character in a situation that character has never been in (like Tony Stark baking a cake) the model can do a half-decent job of continuing the story, including elements of both Tony Stark's life (e.g. his assistant Jarvis) and the process of making a cake (pouring flour, etc.) This is clearly the combination of two unrelated concepts in the neural network state that is used to generate the probabilities for each next word in the story. But though the language model is able to do this, it can't form long term plans, or even maintain any real consistency over more than a few sentences. So I think Vyshedskiy is lumping multiple abilities, all of which people have to have to be able to do the actions he wants to explain, into one ability of "mental synthesis." Without other skills (which apes may already have?) mental synthesis alone is not able to do all the work he wants it to do.
I highly recommend the book, but if you want a shorter read, his recent paper on the topic ("Language Evolution to Revolution")covers all the same material with fewer examples and less background material, and includes an essentially "historical fiction" account of the twin-brothers hypothesis, which I enjoyed. The digital version of both the book and the paper are available for free on the web.
About 60,000 years ago, something fundamental seems to have shifted in the human mind. Before that point, you have artifacts-- stone spear points, notches on antlers, burial of the dead-- but very little progress or invention. Early Homo Sapiens was better at making spear points than Homo Neandertalensis, who was better than Homo Erectus, but in each case the shift came with the evolution of the species, and then stayed unchanged for tens of thousands of years. But after this point in time, everything changes. People spread quickly into every part of the globe, including places only reachable by boat. Artwork appears everywhere: creative, imaginative, fantastic. New tools of every kind begin to appear. New ways of organizing society pop up. People are able to organize into larger and larger groups. We either woke up, or we first began to dream.
So what changed? Looking at skeletons, there is no difference between members of our species before and after the change. We already had the ability to speak, to control our hands finely, to walk upright, to craft spears, to communicate to others. What must have changed is some more subtle evolution in how the brain is organized.
Until I read Sean Carroll's Endless Forms Most Beautiful, I didn't understand that evolution mainly works its changes to the body by modifying the timing and extent of developmental processes. A giraffe grows longer legs because a mutation or genetic recombination causes the "keep growing" signals to persist a little longer; and its longer legs enable it to reach more leaves and cover more distance in each step, so it is able to pass on those genes which control how long that development process persists. Vyshedskiy proposes that something similar happened to the development of one part of the prefrontal cortex. The juvenile period, where those neurons are able to grow and adapt, lasted a little longer, long enough that individuals would have already had time to learn a large vocabulary when a myelination process took place, allowing these controlling neural signals to reach parts of the brain already associated with memories. The growth of the prefrontal cortex enabled what Vyshedskiy calls "mental synthesis." It is the process of bringing into alignment the sychronous neural firing of one memory with the firing of another memory to form a new concept that is a combination of both.
This change, he claims, made all the difference. Before, it was possible to learn hundreds or thousands of words and associated concepts. But with the ability to recombine concepts to create new ones, people gained the ability to form an unlimited number of new propositions. Before the change, people were very good at dealing with situations that had happened before, because they had excellent memories and were able to learn the skills of their parents through direct observation. But after the change, people were able to imagine new situations that had never occurred. They could invent new tools (like needles with holes for thread) and new ways of hunting (like using long, narrowing V's made of stone walls to chase game into) and communicate these complex ideas without direct demonstration to others who had the ability to understand from only hearing something described.
The ability to use prepositions (over, under, next to), recursive grammar, and other features of human language missing from all animal languages seems to be associated with the proper development of this part of the prefrontal cortex in the right kind of environment. When children grow up past the age of six without being exposed to language with these features, they are never able to learn them-- it is a permanent disability. However, when a group of children invent a language without being exposed to other languages (as has happened several times with communities of deaf children, for instance) it includes these features. It seems that whenever you have a community of people who want to communicate, they will spontaneously invent language in its full richness. But without that, the children are not only unable to learn key features of language, their ability to perform many other skills that require imagination are also impaired. They can't solve problems they haven't already seen solved. They can't understand the difference between the idea of a snake biting a dog or a dog biting a snake: they will always tend to confuse the two, because their brain is just creating a kind of stew of the idea of a dog, the idea of a snake, and the idea of biting, rather than creating the idea of a snake biting a dog or vice versa.
His theory includes a detailed model of how this process works in the brain. When they descended from the trees onto the savannah, people needed to be better at putting together visual clues to the presence of predators into the notion of what kind of predator they were facing. So over millenia, the visual system devloped the ability to entertain hypotheses and combine ideas by changing the firing patterns of two disconnected ideas to bring them in synch and turn them into one idea. This was able to occur due to changes in the myelination of long neural connections, which slowed down or sped up the rate at which signals traveled in order to bring them in synch. This ability to form new concepts visually would extend to the ability to form new concepts linguistically, to talk about not just a tree and a bear, but a bear in a tree.
So if you have to have a community for language to develop, but it only occurs due to a mutation, how could language ever have occurred? Vyshedskiy imagines a very specific event happening in one family: an unusual pair of identical twins are born. They are slow to develop: they don't avoid danger at the age of two like the other children. But they invent their own way of communicating between themselves, and as they get older begin to lead the community to do things that have never been done before. They are succcessful, the tribe prospers, and within a few generations the genes have spread throughout the population.
It's a beautiful theory, incorporating evolutionary theory, neuroscience, child development, art history, and many other threads. Vyshedskiy provides a long list of predictions and ways his theory could be falsified. This is as solid science as has ever been done when dealing with these kinds of questions.
Still, I have my doubts. Here are three issues that he didn't discuss which pose difficulties for the theory:
1. What about aphantasia? Vyshedskiy spends a lot of the book talking about the development of the primate visual system, because he sees mental synthesis as happening in the visual system. It is, quite literally, imagination: the ability to form a mental image of something one has never seen by combining things one has seen. But some people completely lack this imagination ability, yet are able to perform without difficulty in everyday life. He presents a list of six questions that he claims cannot be solved without the ability to visualize something you've never seen:
"Question 1. Mary is taller than Julia. Jennifer is taller than Mary. Therefore, Julia is the shortest girl. Answer: True / False
Question 2. A round wall clock that has been rotated until it is hanging upside down will have a minute hand that points to your right when it is two forty. Answer: True / False
Question 3. If the word, “BOM,” is written under the word, “PRY,” and the word, “KOK,” is written under “BOM,” then the word, “POK,” is formed diagonally. Answer: True / False
Question 4. Six identical triangles can be formed by drawing two straight lines through an octagon’s center point. Answer: True / False
Question 5. If a doughnut shaped house has two doors to the outside and three doors to the inner courtyard, then it’s possible to end up back at your starting place by walking through all five doors of the house without ever walking through the same door twice. Answer: True / False
Question 6. The angle formed by the two hands of a clock is larger than 90 degrees when the time is 6:20. Answer: True / False"
I posed these questions to an acquaintance with aphantasia, and he solved all of the problems using logical reasoning:
"True. It's just a logical puzzle. No visualization needed. Consider replacing height with age.
True. It's just math. From the top, 40 minutes is about 270 degrees. Rotate 180 degrees and it's 90 degrees. 90 degrees is left.
True. Order all 3 words. Then take the first letter of the first word, the second letter of the second word, and the third letter of the third word. POK.
False. Dividing a convex polygon with a line creates at most 2 polygons. Dividing it with 2 lines creates at most 4 polygons. There can't be 6 triangles if there are only 4 polygons.
False. Again, it's purely logical. You can't go back to the start by crossing an odd number of times (3 inner doors). It's like asking if flipping a switch 3 times will turn it back to its initial state.
True. Two hands of a clock always form 2 angles whose total is 360. Hence one of them has to be greater than 90 degrees. From the top, 6 hours is 180 degrees and 20 minutes is a bit over 90 degrees (let's say 91). The angles would be 180-91 (89) and 91-180 (271). These questions require no visualization, and I'm surprised people without aphantasia would feel the need to visualize them."
While I solved them using visuaization, if I had to program a computer to solve them, I would have used the techniques my friend described in order to encode them in a way the computer could solve. I don't feel this is a knock-down argument, though. Vyshedskiy makes it very clear that he is talking about an ability that underlies both visual imagination AND language. So if my friend can solve them through language and math, he could still be using this ability in some way, creating results available to other parts of his brain, but somehow not reaching the parts associated with conscious perception.
2. What about less extreme creativity? One example Vyshedskiy gives of recombination is an early sculpture of a man with a lions' head. This is clearly a result of imagination, in no uncertain terms. But other situations , much less dramatic, also seem to involve conceptual combination. Suppose a young fox finds itself in a kind of field it has never seen before, covered with cold, white stuff. It plays in the field a while, getting a sense for how the snow behaves. Now it sees a young rabbit in the snow. It has chased rabbits before, but never in the snow. In order to chase the rabbit, it needs to somehow combine the ideas of "chasing rabbit" with "running through snow." Just because this is a more commonplace occurance, doesn't mean that the same kind of thing, combination of ideas, hasn't taken place. Vyshedskiy tries to head this off in specific cases, showing that what seems to be creative thought in animal experiments could actually be a result of instincts and learning from experience, but it isn't convincing in general. I think there would need to be a lot more experiements with animal creativity and problem solving before we could really delineate what they can and can't do.
3. What about Machine Learning neural language models? I've been working for the last few years with neural network language models trained on vast text corpora. The most recent of these can do some pretty incredible things. For example, given a prompt that puts some popular fictional character in a situation that character has never been in (like Tony Stark baking a cake) the model can do a half-decent job of continuing the story, including elements of both Tony Stark's life (e.g. his assistant Jarvis) and the process of making a cake (pouring flour, etc.) This is clearly the combination of two unrelated concepts in the neural network state that is used to generate the probabilities for each next word in the story. But though the language model is able to do this, it can't form long term plans, or even maintain any real consistency over more than a few sentences. So I think Vyshedskiy is lumping multiple abilities, all of which people have to have to be able to do the actions he wants to explain, into one ability of "mental synthesis." Without other skills (which apes may already have?) mental synthesis alone is not able to do all the work he wants it to do.
I highly recommend the book, but if you want a shorter read, his recent paper on the topic ("Language Evolution to Revolution")covers all the same material with fewer examples and less background material, and includes an essentially "historical fiction" account of the twin-brothers hypothesis, which I enjoyed. The digital version of both the book and the paper are available for free on the web.
March 24, 2025
I don't know if the author has tapped the idea of the development of mental synthesis in individuals born blind or not. I think it has been neglected.
I made a quick search using AI upon the assessment of Mental synthesis theory (MST) in individuals born blind and it answered that it is possible. individuals born blind can construct their own models using auditory and spatial parameters. the brain which is very well known by its plasticity can shift the use of occipital visual cortex to deal with the outer environment through auditory and tactile stimuli.
here I can quote Roger Bartra's narrative about Hellen Killer and her epic story. It seems that her brain was able to construct its images using touch and hearing sensations.
this magnificent book intersects with Roger Bartra's book (the anthropology of the brain) through the insistence upon the complementary union between culture circuits and neural circuits.
Both books had shed light on a very fascinating concept, which is out of incompleteness emerges perfection i.e. Roger Bartra suggested that the human brain was conceived with incomplete neural circuits which craves to be completed through engagement with the outer environment. this union culminates in the creation of what he calls the exocerebrum.
Andrey Vyshedskiy's conjecture is more or less similar to Bartra's conjecture. it appears that the last mutation which entails the delayed maturation of the human prefrontal cortex with all its drawbacks, has given the brain an invaluable opportunity to finalize the process of isochronus connectivity through proper myelination of its fibers. this proper myelination had optimized the prefrontal cortex (PFC) to exercise what he calls (top down control). the essence of the process of top down control resides in the ability of the PFC to synchronize different neuronal ensembles in different location. the tools by which the PFC accomplishes its task is through properly myelinated projections (fibers).
I think such book will enhance my appetite for delving into this subject with enthusiasm.
I spent a very good time with Andrey Vyshedskiy.
I made a quick search using AI upon the assessment of Mental synthesis theory (MST) in individuals born blind and it answered that it is possible. individuals born blind can construct their own models using auditory and spatial parameters. the brain which is very well known by its plasticity can shift the use of occipital visual cortex to deal with the outer environment through auditory and tactile stimuli.
here I can quote Roger Bartra's narrative about Hellen Killer and her epic story. It seems that her brain was able to construct its images using touch and hearing sensations.
this magnificent book intersects with Roger Bartra's book (the anthropology of the brain) through the insistence upon the complementary union between culture circuits and neural circuits.
Both books had shed light on a very fascinating concept, which is out of incompleteness emerges perfection i.e. Roger Bartra suggested that the human brain was conceived with incomplete neural circuits which craves to be completed through engagement with the outer environment. this union culminates in the creation of what he calls the exocerebrum.
Andrey Vyshedskiy's conjecture is more or less similar to Bartra's conjecture. it appears that the last mutation which entails the delayed maturation of the human prefrontal cortex with all its drawbacks, has given the brain an invaluable opportunity to finalize the process of isochronus connectivity through proper myelination of its fibers. this proper myelination had optimized the prefrontal cortex (PFC) to exercise what he calls (top down control). the essence of the process of top down control resides in the ability of the PFC to synchronize different neuronal ensembles in different location. the tools by which the PFC accomplishes its task is through properly myelinated projections (fibers).
I think such book will enhance my appetite for delving into this subject with enthusiasm.
I spent a very good time with Andrey Vyshedskiy.
Displaying 1 - 2 of 2 reviews