The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning

by Bor, Daniel

  Without grouping together or fully processing any items in very busy surroundings, we usually only have a vague, faint conscious impression of its details. For instance, occasionally we may catch only the briefest glimpse of a scene and just have a gist of the objects in it. Our sense of gist reflects the fact that attention has two clear stages: The first, meager, less interesting stage of attention, and indeed awareness, is where we get a weak sense of everything around us, as if we’re not really attending to anything—or rather, we are attending to everything in the same minimal way. This lasts for about 200 milliseconds. A short time later, though, the second form of attention kicks in, which is goal driven. Our neuronal landscape shapes itself according to the task at hand, and we start to hone in on interesting details—there’s my wife in the station, say.

  During this second stage, our brains then calculate exactly what it is we want to focus on, what the few objects are that really matter. This important subset of our world gets a generous attentional boost, and we are far more aware of what matters. Everything else gets suppressed, and our awareness of whatever is outside our working memory and focus of attention may become invisible.

  Scientists have seen the neural equivalent of this story firsthand in a part of the monkey brain that codes for visual objects. Known as the “inferotemporal cortex,” this region has certain neurons that fire strongly for one particular item—say, a flower—and weakly for another—maybe a mug. Leonardo Chelazzi and colleagues used electrodes to study these neurons, one by one, when a monkey was looking for a particular target object that would appear on the screen—such as the flower—to get a reward. Whether or not a given inferotemporal cortex neuron was responsive to flowers, it would initially peak in the same way, as if everything that the monkey was looking at was always provisionally interesting. Only after a few hundred milliseconds would the neuron show its true form. If the neuron wasn’t interested in flowers, its activity would die away, but if it was interested, then its activity would continue to climb strongly. So these neurons, at the business end of how the brain attentionally responds to stimuli, have a two-stage firing pattern—the first is like getting a faint gist of the scene, while the second is all about carrying out a goal, with neurons shaping their activity to reflect what’s important and what’s not.

  In our sense of gist, there is no second stage, or rather, because the input was so weak and transitory, the second stage is merely a copy of the first stage, and so there is minimal or random shaping of the input. Consciousness is unfocused and can randomly, weakly recognize a handful of objects from that brief glance.

  When we grasp the gist of a scene, imperfect as it is, nevertheless at least some attention has to be involved. We can show this by seeing what happens when we completely remove attention from that brief glance. Michael Cohen and colleagues recently carried out just such a task. Subjects watched a rapid stream of different images, which changed every 100 milliseconds. Most of the scenes were just boring color swatches, but one of them in the middle was an interesting real-life scene, say of a city view replete with many skyscrapers. If this was all the subjects had to do, then almost everyone at least noticed the scene and could answer basic, nonspecific questions about it, such as whether the scene was of a beach or a mountain. But if they simultaneously had to perform a very attentionally demanding task, such as keeping track of a set of moving objects superimposed on the images, then only 12 percent of the subjects noticed any scene whatsoever. This clearly shows that we need at least to allocate some attention in order even to get a weak impression of a scene.

  And in fact, for any contents of awareness you’d care to name, including tremendously simple features—such as a colored dot, or the angle of a simple patch of grey—if you carefully and fully divert attention away from the feature, it fails to enter consciousness.

  So attention is certainly a necessary gating component of consciousness, and while full consciousness of some detail means it has to be strongly attentionally favored as it firmly enters our limited working memory, the same working memory holder can weakly store an approximate group of items that we are faintly conscious of. Occasionally our entire working memory is even called upon to recreate a brief glimpse of a scene, but the lack of detailed analysis or pointed attention is reflected in our very imperfect awareness of the features in front of us.

  CHUNKING AND CONSCIOUSNESS

  Now returning to chunking, although this process can vastly increase the practical limits of working memory, it is not merely a faithful servant of working memory—instead it is the secret master of this online store, and the main purpose of consciousness.

  So far I’ve argued that attention is the gatekeeper of awareness. Sometimes it chooses what enters consciousness because of pressing biological issues, such as a potential danger, and sometimes it chooses what enters based on a deliberate goal we have set ourselves. But whatever enters consciousness reflects a first guess, a provisional analysis, that this item is currently very relevant to us, based on our various needs. And the output of attention and the arena for consciousness is our working memory, which is limited to a maximum of about four or so items. But, crucially, all those objects are processed as deeply as our brains allow, and this makes every detail of every item available in a unified way. We are then free to apply various strategies to further examine the items, notice similarities and differences between them, combine them, swap them around, and so on. I’ve repeated the mantra throughout this book that consciousness is concerned with information—specifically, useful, structured information. Chunking is the main catalyst within the bubbling cauldron of working memory where we convert the raw dust of data into molten gold, where basic information from our senses joins the highly refined, hierarchical edifice of meaning that we’ve been building up from birth.

  There are three straightforward sides to chunking processes—the search for chunks, the noticing and memorizing of those chunks, and the use of the chunks we’ve already built up. The main purpose of consciousness is to search for and discover these structured chunks of information within working memory, so that they can then be used efficiently and automatically, with minimal further input from consciousness.

  First the search: Surprisingly, the straightforward result that working memory is limited to four items was only accepted relatively recently, at the turn of the twenty-first century. For the entire half century preceding this, most psychologists assumed that our working memory capacity was around double this, mainly because most researchers failed fully to acknowledge how ubiquitous human strategic processing is and how we all, as a matter of course, use these strategies to boost performance.

  I have attended hundreds of research talks over the years, and at these seminars I’ve heard a particular complaint again and again. It can involve any lab, almost any kind of experiment, and any human population group: However tightly you try to control an experiment, if it poses any kind of challenge to the subjects, those pesky human volunteers will almost always find some strategy to improve performance, usually in a way that neatly makes the experiment invalid. Human innovation is not confined to inventions for revolutionary cyclonic vacuum cleaners and state-of-the-art tablet computers—it is happening almost all the time in all of us, whenever we are awake. Searching for and then finding useful strategies for solving problems, whether large or small, is a signature feature of consciousness.

  Perhaps what most distinguishes us humans from the rest of the animal kingdom is our ravenous desire to find structure in the information we pick up in the world. We cannot help actively searching for patterns—any hook in the data that will aid our performance and understanding. We constantly look for regularities in every facet of our lives, and there are few limits to what we can learn and improve on as we make these discoveries. We also develop strategies to further help us—strategies that themselves are forms of patterns that assist us in spotting other patterns, with one example being that amateur track runner developing tactics to link digi
ts with running times in various races.

  One problematic corollary of this passion for patterns is that we are the most advanced species in how elaborately and extensively we can get things wrong. We often jump to conclusions—for instance, with astrology or religion. We are so keen to search for patterns, and so satisfied when we’ve found them, that we do not typically perform sufficient checks on our apparent insights.

  And we really are a decidedly strange species for actively seeking out games with patterns in them, when such activities seem to serve no biological function whatsoever, at least not in any direct way. It’s as if we were addicted to searching for and spotting structures of information, and if we do not exercise this yearning in our normal daily lives, we then experience a deep pleasure in artificially finding them. Crossword and sudoku puzzles are obvious examples, but there are many other types of games, quizzes, puzzles, and so on that inject pleasure into our lives because of the sense of satisfaction we feel when we spot beautiful structures.

  And there are some particularly mad people, such as myself, who even decide to dedicate their careers to searching for patterns within a set of information. Scientists may well be motivated to improve society by their discoveries, but most are largely driven each day by their curiosity—a desire to convert some messy pile of experimental data into an elegant, neat little explanation. When describing what I do to those outside of research, I regularly find the most useful analogy is that science is like trying to solve a huge, fuzzy crossword puzzle.

  But hobbies in searching for patterns are not by any means limited to the sciences. The arts, too, generate their richness and some of their aesthetic appeal from patterns. Music is the most obvious sphere where structures are appealing—little phrases that are repeated, raised a key, or reversed can sound utterly beguiling. This musical beauty directly relates to the mathematical relation between notes and the overall logical regularities formed. Some composers, such as Bach, made this connection relatively explicit, at least in certain pieces, which are just as much mathematical and logical puzzles as beautiful musical works.21

  But certainly patterns are just as important in the visual arts as in music. Generating interesting connections between disparate subjects is what makes art so fascinating to create and to view, precisely because we are forced to contemplate a new, higher pattern that binds lower ones together. And literature is most powerful when it is using exactly the same trick.

  We are alone in the animal kingdom in just how aggressively we constantly search for patterns, and even in how they may be a source of much of our pleasure, both in our creative acts and in our more receptive appreciation of certain hobbies.

  The second aspect of chunking is the actual detection of these chunks of structured information within consciousness, and this is where the most central purpose of consciousness resides. What do I mean by patterns, structure, or regularities (words that I use interchangeably)? To take an extreme example, a million 1s and then a million 0s can either be seen as 2 million pieces of information, which would take about three times the length of this book to write out, or we can simply transform those 2 million items into just a single sentence by saying, “It’s just a million copies of 1 and then a million copies of 0.” In other words, spotting patterns is about finding redundancy in the information. You can compress the information into a different, smaller, and more useful form by spotting parts that repeat in some way or other, and, ideally, capturing the repetitions in a rule.

  If we can successfully turn any group of data into a pattern or rule, then near-magical results ensue. First, we no longer need to remember that mountain of data—we simply need to recall one simple law. But the benefits don’t just stretch to memory. We’re also, crucially, able to predict all future instances of this data, and so control our environment more efficiently. The rule may even capture something about the mechanism of the data, allowing us to understand it in a more fundamental way.

  Say I’m a prehistoric man. Winter is closing in and my family and I are starving. We dig up some potatoes, which at first sight look edible. We take a bite and spit it out in disgust. I chuck the potatoes on the fire, out of rage. A few hours later, when the fire has died down, I pick the potato up, feel that it has softened considerably, and take another bite. It’s delicious. A few months later, exactly the same set of events happens. I try a raw potato, chuck it in the fire in rage, then a few hours later try again to find it not only edible but delicious. Now I could just remember these as two completely separate episodes in my life and move on. Or I could detect a possible pattern—repeated connected instances between food and fire, with fire making potatoes edible. I then no longer need to remember what the weather was like in each of these instances, where I placed my fire, or what words my children said at the time. All that matters is that fire makes potatoes edible. Now that I’ve detected a pattern, I can consolidate the crucial elements of my memory, thus lowering the load; apply this memory chunk to all future instances of fire and potatoes; and start thinking about other similar organic objects that might benefit from a similar treatment—perhaps sweet potatoes or squashes. By crystallizing and compressing my memory, I’ve actually gained a considerable amount of power over the environment, and my family is less likely to starve as a result.

  Some of our greatest insights can be gleaned from moving up another level and noticing that certain patterns relate to others, which on first blush may appear entirely unconnected—spotting patterns of patterns, say (which is what analogies essentially are).

  It’s difficult to overestimate the extent of learning that is captured by chunking processes. The example of the volunteer who heard digit sequences for two years dramatically illustrates how chunking can vastly increase our short-term memory capacity. But chunking is the main process that we consciously use to turn any novel pattern into a structured part of our memories, which is what almost all learning involves. Our long-term memory store, with thousands of related items, is usually unconscious, waiting loyally for our conscious minds to retrieve some item. But at one point in the past each item was met anew, consciously labeled as important, as relating to other features of our preexisting knowledge, and laid down in memory. The initial stages of learning are always the hardest, but once the first foundations are built, we can connect new items with what we’ve already memorized; as the tapestry of knowledge builds, it becomes ever easier to learn a new part of a topic, because it increasingly connects to related memory items. Closely connected individual items form chunks together, which then connect up themselves in ever larger bound objects in memory. In this way, we can use consciousness—and chunking—to create a highly functional, hierarchical, interrelated bank of knowledge, where, by the time we reach adulthood, most seemingly novel items have some preexisting context. And these heavily embedded prior expectations from the fruits of our vast learning can in turn heavily guide our attention to decide what to load into our working memory, furthering our chances to discover in awareness something novel or important by which to incrementally improve our world model.

  So, chunking within working memory is both the arbiter and the indexer of our long-term memory store, always striving to make what’s most important to us most easily accessible, and to forge new groups out of apparently independent items, based on the patterns we discern. Consciousness and chunking allow us to turn the dull sludge of independent episodes in our lives into a shimmering, dense web, interlinked by all the myriad patterns we spot. It becomes a positive feedback loop, making the detection of new connections even easier, and creates a domain ripe for understanding how things actually work, of reaching that supremely powerful realm of discerning the mechanism of things. At the same time, our memory system becomes far more efficient, effective—and intelligent—than it could ever be without such refined methods to extract useful structure from raw data.

  LANGUAGE—JUST ONE KIND OF CONSCIOUS CHUNKING?

  Language is a special case, since, by learning a language, we
can exponentially increase our capacity to learn more generally via the organization of our own thoughts, via books, teachers, the Internet, and any other form of human communication that can transmit well-chunked information. Whether any other species can start to learn some components of a grammatical language is a controversial question. What’s not controversial is that even if other animals can learn some aspects of language, humans dramatically outshine other species in this sphere, picking up both a vocabulary of thousands of words as well as a complex grammatical structure. All of this is due to chunking.

  As we learn language for the first time, we constantly attempt to make successful inferences between the sound of the word we’ve just heard and the key feature of whatever else we’ve just experienced through our senses. We slowly build up our language, with many words initially starting as overly general chunks. For instance, our baby daughter started saying “Mama” quite early on, which initially excited my wife to no end, until we realized it merely meant she was generally unhappy. But language soon allows us to use the linguistic objects we’ve already learned to hone our skills further, building up our rich web of meaning.

  Many psychologists believe in a “language instinct”—a set of uniquely human brain regions and mental skills built especially for language. My view instead is that language emerges out of our more general capacity to make conscious chunks. As consciousness and the ability to chunk begin to flower, this allows the child to extract these language chunks from what she hears, just as she’s learning about many other types of structured information, such as how to walk, how to deal with complex social situations, or how to interact with her more advanced toys. At the same time, adults learning an artificial grammar, akin to acquiring the rules of a novel language, do not activate some special language region. Instead, they activate just the same brain areas as when they are performing any other chunking task, such as encoding structured spatial sequences. And one would expect a language instinct to have genes associated with it, giving us a specific helping hand from our earliest days. To date, there is controversial and patchy evidence for this.22 Instead, we have a sufficiently advanced form of consciousness that is hungry for patterned, hierarchical information and playfully active in its search for powerful, structured cognitive tools to manage this information—of which language is perhaps the most rich, useful example. After all, language allows yet another level of information processing in nature, where chunks of insight can be passed between people, and collaboration between members in a group can generate innovative new ideas, which would not have been possible alone.