Selective attention and the perceptual analysis of odor mixtures.

Two psychophysical methods were used to investigate the capacity of humans to identify the constituents of odor mixtures consisting of up to six components. With one method subjects were required to identify all the components present in each stimulus; with the other, a selective attention procedure was used where subjects had to identify only one component at each trial. Little difference was found between the levels of identification obtained with both methods, reinforcing the finding that humans have great difficulty in identifying more than three components in an odor mixture and indicating that it is unlikely that olfactory adaptation influenced the identification process.