“The left hemisphere’s ‘stickiness’, its tendency to recur to what it is familiar with, tends to reinforce whatever it is already doing. There is a reflexivity to the process, as if trapped in a hall of mirrors: it only discovers more of what it already knows, and it only does more of what it already is doing. The right hemisphere by contrast, seeing more of the picture, and taking a broader perspective that characteristically includes both its own and the left hemisphere’s

One way of thinking of this is in terms of feedback systems. Most biological systems seek homeostasis: if they move too far in one direction, they stabilise themselves by self-correction. This is ‘negative feedback’, the most familiar example of which is the operation of a thermostat: if the temperature constantly tends to drop, the thermostat triggers a heating system that will act to bring the temperature back to the desired level. However, systems can become unstable and enter a situation in which ‘positive feedback’ obtains – in other words, a move in one direction, rather than producing a move in the opposite direction, serves to promote further moves in the same direction, and a snowballing effect occurs. The right hemisphere, then, is capable of freeing us through negative feedback. The left hemisphere tends to positive feedback, and we can become stuck.”

– Iain McGilchrist, The Master and His Emissary