I propose that neural cognition is supported by non-neural storage of a 3-D model of local space, used in the planning of movements. Information is stored in wave-like excitations which couple to neurons in the thalamus, with the wave-vectors of excitations representing spatial positions. This hybrid of neural and non-neural cognition may have fitness advantages over any purely neural mechanism -- in information capacity, geometric accuracy, and fast selective retrieval. The wave excitations may be sustained on a Bose-condensed state of some excitation in the brain, by a mechanism like those investigated by Frohlich, Umezawa, Vitiello and others. These states, being frictionless, can store information indefinitely at low energy levels, insulated from thermal noise, so are an ideal substrate for memory. If a Bose-condensed state is a 3-D representation of local reality, it may be the basis of phenomenal consciousness (which is also a model of local reality). The resulting theory of consciousness is highly constrained, and agrees well with the main properties of conscious experience. In this account, consciousness arises from a very simple state of matter, rather than from complexity; and it evolved to meet one of the strongest selection pressures on the brain.