Each brain is exposed to different circumstances. It's very likely that your brain is unique in the history of the universe.
Gerald EdelmanHayek made a quite fruitful suggestion, made contemporaneously by the psychologist Donald Hebb, that whatever kind of encounter the sensory system has with the world, a corresponding event between a particular cell in the brain and some other cell carrying the information from the outside word must result in reinforcement of the connection between those cells. These day, this is known as a Hebbian synapse, but von Hayek quite independently came upon the idea. I think the essence of his analysis still remains with us.
Gerald EdelmanEvolution works by selection, not by instruction. There is no final cause, no teleology, no purpose guiding the overall process
Gerald EdelmanMost theoretical work since the proposals of Hebb (1949) and Hayek (1952) has relied upon particular forms of dependent synaptic rules in which either pre- or postsynaptic change is contingent upon closely occurring events in both neurons taking part in the synapse.
Gerald EdelmanThe analogy between the mind and a computer fails for many reasons. The brain is constructed by principles that assure diversity and degeneracy. Unlike a computer, it has no replicative memory. It is historical and value driven. It forms categories by internal criteria and by constraints acting at many scales, not by means of a syntactically constructed program. The world with which the brain interacts is not unequivocally made up of classical categories.
Gerald Edelman