ABSTRACT
We feel ourselves to be one united self, experiencing one stream of consciousness at a time, yet look inside the brain and we find a parallel system of great complexity and diversity. The ‘binding problem’ concerns how the features of an object are brought together. For example, different parts of the visual system deal with colour, shape, and movement, but these must all be brought together for us to see one moving object. Different senses must also be united by ‘multisensory integration’. Time is also a problem because different brain processes operate at different rates, and subjective and clock time must be integrated with each other. Among possible solutions are binding by synchrony, the theory of micro-consciousness, and integrated information theory (IIT). Enactivist theories point out that the whole organism is intrinsically united through its actions; illusionist theories claim that the unity of consciousness is an illusion and we need to ask how the illusion comes about. Finally, this chapter explores what happens when consciousness is more or less unified than normal, using examples from synaesthesia, split brains, amnesia, and hemifield neglect. These atypical cases may make us question what we assume about normal experience.
