activity and its putative role in information processing and learning. Ann. Rev. Physiol. 55:349-374 Skinner, J.E., Martin, J.L., Landisman, C.E., Mommer, M.M., Fulton, K., Mitra, M., Burton, W.D., Saltzberg,B. (1990) Chaotic attractors in a model of neocortex: dimensionalities of olfactory bulb surfac