Being You: A New Science of Consciousness

by Anil Seth

Any pattern, whether a photo of your summer holiday or an electrical echo unfolding across the brain in time and space, can be represented as a sequence of 1s and 0s. For any nonrandom sequence there will be a compressed representation, a much shorter string of numbers that can be used to fully regenerate the original. The length of the shortest possible compressed representation is called the “algorithmic complexity” of the sequence. Algorithmic complexity will be lowest for a completely predictable sequence (such as a sequence consisting entirely of 1s, or of 0s), highest for a completely random sequence, and somewhere in the middle for sequences that contain some amount of predictable structure. The “zip” algorithm—which calculates what’s called “Lempel-Ziv-Welch complexity,” or “LZW complexity” for short—is a popular way of estimating the algorithmic complexity for any given sequence.