Aug 03 2017


brainpuzzleIf I gave you a string of digits to remember, how many do you think you could handle? For example, try to remember the number – 8945557302. That’s 10 digits. Most people can handle only 7, and there is a specific neurological reason for this. Our working memory is wired for about 7 bits of information (give or take 1-2 bits). Now, try to remember the number as 894-555-7302. That is recognizable as a phone number, and despite the fact that the individual digits exceed our bit capacity, most people can remember such numbers.

Grouping bits of information into recognizable patterns in order to make them easier to remember is a phenomenon called chunking, first described by George Miller in his 1956 book, The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information.

Chunking is best established as a mnemonic device. Miller and others conducted experiments to see how much chunking as a strategy could extend the limits of human memory. For example, the typical number of binary bits, such as Morse code, people can remember is 9. However, someone who understands morse code will chunk the individual bits into groupings of three, each one representing a letter. They will then group letters into words and words into sentences.  This type of chunking extended memory from 9 to 40 binary bits.

Another study involved a runner tasked to remember strings of digits, again starting with a typical digit span of 7. However, he was encouraged to chunk the digits into race times – a meaningful pattern with which he was very familiar. With a little practice he increased his digit span to 80 numbers.

What these and other studies show is that chunking data into groups is a very effective strategy for managing large sets of information. Further, the more meaningful the groupings, and the more familiar the patterns, the more effective this strategy is. Meaningful patterns are important. For example, chess masters can famously memorize entire chess boards, with the position of every piece on the board. However, they cannot remember random placings of chess pieces, only meaningful placements that result from actual game play.

The phenomenon of chunking extends beyond bits of information. We also chunk motor skills, by breaking down a complex task into definable combinations of movements.

The deeper question is – why is chunking so universal and so useful? It seems likely that is results from a basic fact of how our brains process information. This fits with the independent research that shows that our brains are essentially pattern-recognition machines. The neurons of our brains are organized into massive parallel processors that seek recognizable patterns – visual, auditory, numeric, linguistic, temporal, spatial, and conceptual patterns.

Since our brains essentially remember patterns, it makes sense that we would naturally chunk data into groups. Further, we either impose an arbitrary pattern on those chunks, or we relate them to a pattern with which we are already familiar. Any 10-digit number can be remember as a phone number, for example.

Patterns are also nestled. Language is probably the most obvious example. We have individual letters that represent sounds. These are grouped into patterns called words. Words are then grouped into sentences, which are grouped into paragraphs, which are grouped into chapters, poems, essays, or other specific forms. Even pictoral languages follow this overall pattern, with individual characters representing words instead of phonemes. Even then, individual characters are often clusters of several smaller characters.

We also chunk the natural world. We don’t just see a trunk, branches, and leaves. We see a tree – all the parts make a whole pattern that we conceptualize as one thing. Further, we may see a grove, or an entire forest. Similarly, we don’t just hear notes, we hear a melody, a refrain, a movement, a song, or even an entire opera or symphony.

Our brains organize information into nestled chunks of meaningful patterns. This is an adaptive and effective way to deal with massive amounts of information. It can also be constraining, however, since once we are familiar with a pattern we tend to impose it on information. This is why we also need to be flexible – able to learn knew patterns, unlearn patterns that are flawed or inaccurate, and make adjustments as new information is available. That can take a lot of effort, however.

We also tend to make arbitrary chunks – categories that are inherently subjective. The analogue world in which we live isn’t divided into neat categories, but our brains need to break up that continuum into definable chunks we can label and conceptually organize into patterns. That is why we agonize over whether Pluto is a planet, a dwarf planet, or something else. Pluto is what it is, but we feel the need to place it in its proper chunk.

Understanding chunking can be helpful. That is a common theme of this blog – understanding how the brain works so that we can more effectively use it as our primary tool for navigating the world, and avoid falling into the pitfalls derived from the limitations of our brains. Chunking, at the very least, is a useful strategy for memorizing information. But it also helps us understand how our brains deal with information, and avoid becoming a slave to this tool.

Patterns are useful, even necessary, but you need to question them and be willing to abandon or modify them.

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