In humans, evidence suggests it has a whole range of benefits, including this one: it keeps the brain healthy by letting neurons prune unnecessary synaptic connections we make during the day. This process, called synaptic homeostasis, prevents the brain from being overrun by useless memories. It's possible that it helps to improve our cognitive performance, while dreams allow us to process our memories. As it turns out, something similar may be occurring when artificial neural networks are allowed to sleep and dream. Yep, you read that correctly.