Neuroscience

During sleep, the brain not only stores memories — it erases them. Research from 2022–2023 found Arc and Homer1a can weaken less-active synapse connections. Forgetting is a feature, not a bug: clearing space helps encode new memories.

During Sleep, the Brain switches into cleanup mode. A 2013 study found that brain cells shrink during sleep, widening the space between them by about 60%, so Cerebrospinal fluid can wash away toxic proteins such as Alzheimer's-linked beta-amyloid 10–20 times faster than when awake.

The 'Five senses' idea hardened for 2,000+ years from Aristotle naming sight, hearing, smell, taste, and touch and declaring there's no sixth sense. But modern Neuroscience counts over twenty, including the vestibular sense for balance and proprioception for limb position.