Olfactory computation and object perception.

Animals that are primarily dependent on olfaction must obtain a description of the spatial location and the individual odor quality of environmental odor sources through olfaction alone. The variable nature of turbulent air flow makes such a remote sensing problem solvable if the animal can make use of the information conveyed by the fluctuation with time of the mixture of odor sources. Behavioral evidence suggests that such analysis takes place. An adaptive network can solve the essential problem, isolating the quality and intensity of the components within a mixture of several individual unknown odor sources. The network structure is an idealization of olfactory bulb circuitry. The dynamics of synapse change is essential to the computation. The synaptic variables themselves contain information needed by higher processing centers. The use of the same axons to convey intensity information and quality information requires time-coding of information. Covariation defines an individual odor source (object), and this may have a parallel in vision.