Bidirectional perception-production relations in phonological development: evidence from positional neutralization.
Many children who neutralize phonemic contrasts in production exhibit diminished perception of the same contrasts. It is usually difficult to determine whether the perception deficit caused the production error, or vice versa; however, the direction of causation has implications for treatment planning. This study examines perception-production relationships in the phenomenon of neutralization in strong position, where children neutralize only in perceptually salient contexts. To test a hypothesis that this phenomenon arises from a child-specific pattern of perceptual sensitivity, a non-word discrimination task was administered to a 4-year-old boy with neutralization in strong position in production. Contrary to the perceptual hypothesis, his discrimination accuracy was greatest for contrasts in initial/strong position, where his production errors occurred. Independent of position, however, his perception of a phonemic contrast he neutralized was decreased relative to other contrasts. This case is argued to constitute evidence that a primary production deficit can cause decreased perceptual ability.