Can AI become conscious? Bach, Escher and Gödel’s ‘strange loops’ may have the answer
This year is the 40th anniversary of the publication of one of the cult books of my generation: Gödel Escher Bach by Douglas Hofstadter. This Pulitzer prize-winning tome was essential reading in the 1980s for emerging geeks like me. But, despite its name, it is not a book about the composer Bach, the artist Escher or even the mathematician Kurt Gödel. It is about consciousness and Hofstadter’s belief that this elusive concept is related to the idea of what he calls “a strange loop”.
To celebrate the anniversary, I am staging a triptych of events at the Barbican in London called Strange Loops, looking at the impact of technology on what it means to be human. I believe that the ideas in the book are now more relevant than at any point over the past four decades. The strange-loop concept may be the key to understanding when and whether the fast-evolving AIs we are creating might become conscious.
What makes a loop “strange”? A strange loop is a cyclical structure that goes through several layers of a hierarchical system to find itself back at the beginning. One layer is contained inside another to permit a strange crossing of these levels so that the higher one suddenly appears embedded in the lower. This is why Hofstadter chose Escher as the perfect illustration of the idea of a strange loop.
Think about the famous Escher image of the monks climbing a quadrangle of squaresthat seem to keep climbing and yet, at full circle the monks step on to the stair they started from. Or the image of two hands each drawing the other. An image of a hand drawing a hand seems to imply the first hand is in a world above the drawn hand. And yet the image confuses us because we can’t work out which is the primary layer.
Hofstadter admitted, when I interviewed him for the Barbican project, that the book was going to have an academic title about the human brain that did not refer to Escher or Bach. But when his father read the first draft he complained that there were no pictures. Hofstadter realised he had had Escher’s images in his mind as he wrote about loops that climb yet return to the beginning. Thus Escher is there to help the reader see the concept of a strange loop. One strand of our triptych at the Barbican explores visual feedback in an interactive installation created by the artist Ben Kreukniet.
There are interesting examples of strange loops in sound. An illusion called a Shepard tone consists of notes that seem to get higher and higher in pitch yet never seem to go beyond audible frequencies. The sound is looped but the frequencies are cleverly chosen to given an illusion of the pitch continually climbing. Bach uses a similar idea in a variation in The Musical Offering. The theme seems to repeat itself, climbing a note higher each time it is played. Yet at a certain point the theme hits the octave and the piece sounds as if it is beginning again.
The variations that make up The Musical Offering illustrate how Bach loved to use algorithms to create complex music from a simple theme.
