The Purpose of Sleep? To Forget, Scientists Say
As someone with no neuroscience background I’ve suspected this for a while just based on how Boltzmann machines work. These are a type of unsupervised artificial neural network.<p>The training algorithm for Boltzmann machines has two phases:<p>1. (Awake phase) Feed the network training data, and increase the weights between neurons that tend to get activated simultaneously in this phase.<p>2. (Dreaming phase) Let the network run without any training input, and decrease the weights between neurons that tend to get activated simultaneously in this phase.<p>This training algorithm wasn’t designed to emulate how human brains work, it just sort of falls out of the math. And yet (1) resembles the Hebbian principle from neuroscience (neurons that fire together, wire together), and (2) resembles the process described in this article. Actually I suspect something stronger than what the article claims based on this: that the connections that get pruned are the ones connecting neurons that fire together while dreaming. It would be nice to have someone who knows stuff about neuroscience comment on this.