Feature-Testing Models and Their Application to Perception and Memory for Speech

Four models of the organization of feature-testing units in the perception of phonemes are developed and tested against data drawn from a number of published studies. The independence model, which asserts that features are tested independently of each other, is conclusively rejected. The response-conditional and stimulus-conditional models require individual feature-testing units to be dependent, respectively, on the responses of other feature-testing units and on the other features present in the stimulus. Both these models handle perceptual confusions very well among stop and nasal consonants, but are less satisfactory for fricatives. Finally, the correct-conditional model requires individual feature-testing units to be dependent on the correctness of the decisions made by other feature-testing units; this model is very poor for perceptual confusions but quite good for mnemonic confusions. In addition, some of the distinctive features currently favoured by linguists are shown to provide unsatisfactory descriptions.

The implications of this study are that perceptual and mnemonic processes are different in certain basic respects, and that many current scaling models are ignoring important types of structure in the data they analyse.