How to Create a Mind: The Secret of Human Thought Revealed

by Ray Kurzweil

The mammalian brain has a distinct aptitude not found in any other class of animal. We are capable of hierarchical thinking, of understanding a structure composed of diverse elements arranged in a pattern, representing that arrangement with a symbol, and then using that symbol as an element in a yet more elaborate configuration. This capability takes place in a brain structure called the neocortex, which in humans has achieved a threshold of sophistication and capacity such that we are able to call these patterns ideas.

Only Homo sapiens have a knowledge base that itself evolves, grows exponentially, and is passed down from one generation to another.

evolutionary process inherently accelerates (as a result of its increasing levels of abstraction) and that its products grow exponentially in complexity and capability. I call this phenomenon the law of accelerating returns (LOAR), and it pertains to both biological and technological evolution. The most dramatic example of the LOAR is the remarkably predictable exponential growth in the capacity and price/performance of information technologies.

The world itself is inherently hierarchical—trees contain branches; branches contain leaves; leaves contain veins. Buildings contain floors; floors contain rooms; rooms contain doorways, windows, walls, and floors.

I made the case that one corollary of the law of accelerating returns is that other intelligent species are likely not to exist. To summarize the argument, if they existed we would have noticed them, given the relatively brief time that elapses between a civilization’s possessing crude technology (consider that in 1850 the fastest way to send nationwide information was the Pony Express) to its possessing technology that can transcend its own planet. 4 From this perspective, reverse-engineering the human brain may be regarded as the most important project in the universe.

The goal of the project is to understand precisely how the human brain works, and then to use these revealed methods to better understand ourselves, to fix the brain when needed, and—most relevant to the subject of this book—to create even more intelligent machines.

pattern recognition theory of mind (PRTM), which, I argue, describes the basic algorithm of the neocortex (the region of the brain responsible for perception, memory, and critical thinking).

The implication of the PRTM combined with the LOAR is that we will be able to engineer these principles to vastly extend the powers of our own intelligence.

the mathematical techniques that have evolved in the field of artificial intelligence (such as those used in Watson and Siri, the iPhone assistant) are mathematically very similar to the methods that biology evolved in the form of the neocortex. If understanding language and other phenomena through statistical analysis does not count as true understanding, then humans have no understanding either.

The operating principle of the neocortex is arguably the most important idea in the world, as it is capable of representing all knowledge and skills as well as creating new knowledge. It is the neocortex, after all, that has been responsible for every novel, every song, every painting, every scientific discovery, and the multifarious other products of human thought.

it would be fair to say that there is more complexity in a single neuron than in the overall structure of the neocortex.

My goal in this book is definitely not to add another quotation to the millions that already exist attesting to how complex the brain is, but rather to impress you with the power of its simplicity.

Einstein articulated my goals in this book well when he said that “any intelligent fool can make things bigger and more complex…but it takes…a lot of courage to move in the opposite direction.”

how does a problem-solving neocortex attain consciousness? And while we’re on the subject, just how many conscious minds do we have in our brain? There is evidence that suggests there may be more than one.

There are experiments that appear to show that we start implementing our decisions before we are even aware that we have made them. Does that imply that free will is an illusion?

what attributes of our brain are responsible for forming our identity? Am I the same person I was six months ago? Clearly I am not exactly the same as I was then, but do I have the same identity?

How could time itself slow down, based only on someone’s speed of movement?

Einstein’s second mind experiment was to consider himself and his brother flying through space. They are 186,000 miles apart. Einstein wants to move faster but he also desires to keep the distance between them the same. So he signals his brother with a flashlight each time he wants to accelerate. Since he knows that it will take one second for the signal to reach his brother, he waits a second (after sending the signal) to initiate his own acceleration. Each time the brother receives the signal he immediately accelerates. In this way the two brothers accelerate at exactly the same time and therefore remain a constant distance apart.

we would see the two brothers getting closer and closer and eventually colliding. Yet from the perspective of the two brothers, they remain a constant 186,000 miles apart.

There are several reasons why I have opened this book with Darwin’s and Einstein’s mind experiments. First of all, they show the extraordinary power of the human brain. Without any equipment at all other than a pen and paper to draw the stick figures in these simple mind experiments and to write down the fairly simple equations that result from them, Einstein was able to overthrow the understanding of the physical world that dated back two centuries, deeply influence the course of history (including World War II), and usher in the nuclear age.

these famous thought experiments reveal the power of human thinking at its finest.

Einstein is widely regarded as the leading scientist of the twentieth century (and Darwin would be a good contender for that honor in the nineteenth century), yet the mathematics underlying his theories is ultimately not very complicated. The thought experiments themselves were straightforward. We might wonder, then, in what respect could Einstein be considered particularly smart.

how many thousands of other observers and thinkers were completely unable to think through these remarkably uncomplicated exercises? One common failure is the difficulty that most people have in discarding and transcending the ideas and perspectives of their peers.

we can get remarkably far in figuring out how human intelligence works through some simple mind experiments of our own. Considering the subject matter involved, mind experiments should be a very appropriate approach.

the distinction between being determined and being predictable is an important one,

I remember how exciting it was when the front-panel lights dimmed right before the algorithm finished its deliberations, as if the computer were deep in thought. When people came by, eager to get the next set of results, I would point to the gently flashing lights and say, “It’s thinking.” This both was and wasn’t a joke—it really did seem to be contemplating the answers—

it did get me to begin to consider in earnest the relationship between thinking and computing.

Reciting the alphabet backward should be a simple task, as it involves exactly the same information as reciting it forward, yet we are generally unable to do it.

Computers can do this trivially. Yet we fail at it unless we specifically learn the backward sequence as a new series. This tells us something important about how human memory is organized.

our memories are sequential and in order. They can be accessed in the order that they are remembered. We are unable to directly reverse the sequence of a memory.

Recall a walk that you took in the last day or so. What do you remember about it?

is likely that you remember relatively few details, even though this is a very recent experience.

we tend to equate consciousness with our memory of events. The primary reason we believe that we are not conscious when under anesthesia is that we don’t remember anything from that period

So with regard to the walk I took this morning, was I not conscious during most of it? It’s a reasonable question, given that I remember almost nothing about what I saw or even what I was thinking about.

Next, think about people whom you have encountered only once or twice. Can you visualize them clearly? If you are a visual artist, then you may have learned this observational skill, but typically we are unable to visualize people we’ve only casually come across to draw or describe them sufficiently but would have little difficulty in recognizing a picture of them.

there are no images, videos, or sound recordings stored in the brain. Our memories are stored as sequences of patterns. Memories that are not accessed dim over time.

You are undoubtedly able to recognize these familiar personalities, even though they are partially covered or distorted. This represents a key strength of human perception: We can recognize a pattern even if only part of it is perceived (seen, heard, felt) and even if it contains alterations. Our recognition ability is apparently able to detect invariant features of a pattern—characteristics that survive real-world variations.

The image is ambiguous—the corner indicated by the black region may be an inside corner or an outside corner. At first you are likely to perceive it one way or the other, though with some effort you can change your perception to the alternate interpretation. Once your mind has fixed on an understanding, however, it may be difficult to see the other perspective. (This turns out to be true of intellectual perspectives as well.) Your brain’s interpretation of the image actually influences your experience of it.

our conscious experience of our perceptions is actually changed by our interpretations.

we are constantly predicting the future and hypothesizing what we will experience. This expectation influences what we actually perceive.

routine procedure before going to sleep. The first step is to brush my teeth. But this action is in turn broken into a smaller series of steps, the first of which is to put toothpaste on the toothbrush. That step in turn is made up of yet smaller steps, such as finding the toothpaste, removing the cap, and so on. The step of finding the toothpaste also has steps, the first of which is to open the bathroom cabinet. That step in turn requires steps, the first of which is to grab the outside of the cabinet door. This nesting actually continues down to a very fine grain of movements, so that there are literally thousands of little actions constituting my nighttime routine.

Although I may have difficulty remembering details of a walk I took just a few hours ago, I have no difficulty recalling all of these many steps in preparing for bed—so much so that I am able to think about other things while I go through these procedures.

this list is not stored as one long list of thousands of steps—rather, each of our routine procedures is remembered as an elaborate hierarchy of nested activities. The same type of hierarchy is involv...

The use of hierarchies allows us to reuse patterns. For example, we do not need to relearn the concept of a nose and a mouth each time we are introduced to a new face.

We do know the neocortex is responsible for our ability to deal with patterns of information and to do so in a hierarchical fashion. Animals without a neocortex (basically nonmammals) are largely incapable of understanding hierarchies.

The neocortex is responsible for sensory perception, recognition of everything from visual objects to abstract concepts, controlling movement, reasoning from spatial orientation to rational thought, and language—basically, what we regard as “thinking.”

Homo sapiens developed a large forehead to allow for an even larger neocortex; in particular we have a frontal lobe where we deal with the more abstract patterns associated with high-level concepts.

Mountcastle hypothesized the existence of mini-columns within columns, but this theory became controversial because there were no visible demarcations of such smaller structures. However, extensive experimentation has revealed that there are in fact repeating units within the neuron fabric of each column. It is my contention that the basic unit is a pattern recognizer and that this constitutes the fundamental component of the neocortex.

It is certainly a useful and necessary part of reverse-engineering the brain to model its interactions at the molecular level, but the goal of the effort here is essentially to refine our model to account for how the brain processes information to produce cognitive meaning.

Human beings have only a weak ability to process logic, but a very deep core capability of recognizing patterns. To do logical thinking, we need to use the neocortex, which is basically a large pattern recognizer.