Dooling, R.J., Okanoya, K., Brown, S.D. and Park, T.J. (1988). The use of multidimensional scaling techniques for revealing perceptual categories for complex stimuli in animals. J. Acoust. Soc. Am. 83, S17.

A combination of operant conditioning and multidimensional scaling techniques for demonstrating natural perceptual categories for complex sounds in small birds are described. Birds are trained using operant conditioning procedures on either a same/different discrimination task or on a task requiring the detection of change in a repeating background. Response latencies are used to construct similarity matrices, and multidimensional scaling procedures are then used to produce spatial maps of complex sounds reflecting perceptual organization. Stimulus similarity is represented by spatial proximity. Stimulus groupings in multidimensional space indicate perceptual categories that can be confirmed by cluster analyses. These procedures have been used to study the perception of complex sounds such as bird calls and speech in small birds, but these techniques should also be useful in examining the perception of complex sounds in other animals. [Work supported by NIH.]