As I have mentioned earlier, emotional states appear to transfer between the hemispheres subcortically, and this transfer is not affected by severing… - Michael S. Gazzaniga

While there are more neural connections within a half brain than between the two halves, there are still massive connections across the hemispheres. Even so, cutting those connections does little to one’s sense of conscious experience. That is to say, the left hemisphere keeps on talking and thinking as if nothing had happened even though it no longer has access to half of the human cortex. More important, disconnecting the two half brains instantly creates a second, also independent conscious system. The right brain now purrs along carefree from the left, with its own capacities, desires, goals, insights, and feelings. One network, split into two, becomes two conscious systems. How could one possibly think that consciousness arises from a particular specific network? We need a new idea to cope with this fact.

The classic example from biology is the huge, towerlike structure that is built by some ant and termite species. These structures only emerge when the ant colony reaches a certain size (more is different) and could never be predicted by studying the behavior of single insects in small colonies.

After my talk, he went into some kind of rant about how the “odd human case” didn’t mean much of anything and that it was sort of a bizarre consequence of prior epilepsy, etcetera.