According to Damasio, a thing achieves self-awareness when its brain models its body, the outside world, and their interactions. At this point, the thing is self-aware, but only from moment to moment. It is not a very interesting creature. If its brain also remembers the past, then the thing is aware of itself as something which has a life history. Now, if this individual is here today, then aeons ago its species has learned to have innate regulations for survival, such as to fear danger and crave food. Armed with emotions such as these, this self-aware thing-with-life-history becomes motivated because it seeks joy, avoids pain, fears death. It becomes lively.
Damasio says the above-mentioned basic self-awareness arises as follows:
The body has myriad internal sensors which sense chemicals in the blood, the heart rate, pain, etc. This huge stream of sensory information is like a (highly multimedia) movie in the brain. Of course, a computer with internal sensors also has this movie. And, if it has the right software, from these sensors it also can form a model of the body at each instant.
But the brain’s wetware also creates an additional model. The above model of the body is embedded in this larger model – Damasio’s “second-order model”. In it, there’s the body, there’s the outside world as sensed by the body’s five external senses, and there are interactions between this outside world and the body, again as sensed by them.
Now, at each instant, the brain has two simultaneous views: One is a view “from the outside” – As if it were an observer, the brain sees (from the second-order model) the body which has a hand, and the hand extending to touch a coffee cup. The other is that the body’s model (the one embedded in the second-order model) reports that its eyes see the cup and, ouch, its skin gets burned by the hot cup. As the hand quickly pulls back, both the body’s model and the second-order model simultaneously report the same fact.
So the brain is presented with this fact: Instant after instant, interacting with one thing out there after another, these 2 views coincide always. It cannot fail to realise that that body is its body – “The thing touching the cup is myself”. The brain becomes aware of the self – it achieves “core consciousness”. From this, arises human consciousness. There seems no reason why machine consciousness cannot arise likewise.
– Damasio, A. 1999. “The Feeling of What Happens: Body and Emotion in the Making of Consciousness”. New York: Harcourt Brace.