The relationship of input and output phonological processing: An evaluation of models and evidence to support them

Abstract

In this paper, we review studies of the relationship between input and output phonological processing and discuss the means by which an interactive activation model that assumes a single phonological network or functionally connected input and output phonological networks could account for apparent dissociations of these two pathways. Following this, we report data from 24 aphasic subjects with word processing deficits that indicate associations between input and output phonological processing. Input phonological measures correlated with output phonological measures, but not with output lexical-semantic measures. Input lexical-semantic measures did not significantly correlate with any of the output measures. We identified one subject, EF, who did not show this overall pattern. She performed well on two measures of phonological input processing (discrimination and rhyme judgements), but produced a high rate of phonological errors in picture naming. On an auditory lexical decision task, however, EF produced a high rate of false alarm errors (misperception of nonwords as words). False alarm errors have been attributed to a disturbance in input phonological processing. Consistent with this hypothesis, the rates of false alarm errors made by this group of subjects on the same auditory lexical decision task correlated with (1) input tasks that require maintaining activation of phonological representations and (2) a measure of output phonological processing (rates of phonologically related nonword errors in picture naming). These results are discussed with reference to current approaches to the study of input and output phonological processing and possible future investigations of this question.