Nørretranders caption: Küpfmuller's diagram of the information flow through a human being: from the senses through the brain (and consciousness) to the motor apparatus. The thick line shows how many million bits from the senses are sent via nerve connections to the brain, which has a very high bandwidth. From the brain the information is sent to the body, which manages about the same amount of information as the senses receive. The thin line shows how the consciousness processes a very little proportion of this information.
I've written previously about The user illusion, cutting consciousness down to size by Tor Nørretranders. The diagrams and captions above and below are taken from the book's sixth chapter "The Bandwidth of Consciousness", and for me they and the evidence that Nørretranders presents are a revelation, in that they emphasise how little we can consciously take in at a time; and hence how designers of e-learning materials need to avoid creating cognitive overload.
25 November 2012 note. Today this 5.5 year old post was linked to from Ycombinator, causing a large spike in traffic. You may want to read and possibly contribute to the discussion that has developed there.
Nørretranders caption: An overview of the information flow through a human being, drawn by up by the Erlangen School (Frank, Lehrl, er al.). A so-called organogram. Just as Küpfmuller's diagram it shows that more information goes in and out of humans than consciousness perceives.