In his book, The Brain, neuroscientist, David Eagleman says:
"… the brain has no access to the world outside. Sealed within the dark, silent chamber of your skull, your brain has never directly experienced the external world, and it never will… Everything you experience – every sight, sound, smell – rather than being a direct experience, is an electrochemical rendition in a dark theatre."
And this:
… our reality is ultimately built in the dark, in a foreign language of electrochemical signals. The activity churning across the vast neural networks gets turned into your story of this, your private experience of the world: the feeling of this book in your hands, the light in the room, the smell of roses, the sound of others speaking.