Despite much intense thinking about how we think, there is still no single theory to explain how the actions of an intricate neural array turn into the deeply felt sense of self we each carry, or that could form a blueprint for an artificial mind. Cognitive theorists, neuroscientists, psychologists, philosophers, experts in AI all have their approaches, showing that the question has yet to be answered to everyone’s or even anyone’s full satisfaction.What most theories have in common is the attempt to show how neurons work together to give unified per- ceptions and thought processes, leading to a coherent sense of con- sciousness. In visual cognition, the mind’s need to bring together different aspects of a seen object into an integrated perception is called the “binding problem.” Some theories hold that consciousness arises from a greater, more inclusive binding process. Others consider it an emergent property, meaning that although it can be traced to neu- ronal behavior, no single neuron is conscious, nor can a simple sum of all the neuronal properties account for consciousness.
These theories cover a wide range—from the view that the mere operation of the parts of the brain constitutes consciousness, to the belief that consciousness arises from as-yet-unknown natural phe- nomena, to the extreme view that the human mind can never fully understand itself. The unsettled nature of the field, and the lack of more than the beginnings of hard data,is shown by the disputes among proponents of different theories,disagreements often relying on asser- tions that depend on key words like “consciousness,”“intentionality,” and “meaning.” Because these words are hardly rigorously defined, the quarrels often represent no more than differences of opinion or interpretation, producing much waste heat and little useful scientific light. Nevertheless, there are nuggets of truth among these conflicting ideas.
The most startling view is that consciousness is illusory, or at least behaves very differently from our internal sense of it. Many people, whether philosophers and scientists or not, find this approach not only counterintuitive but repellent, because it violates cherished