Word Form Retrieval in Spoken Word Production

Abstract

In the auditory picture-word interference task, participants name pictures whilst ignoring auditory distractor words. Previous studies have reported faster naming latencies when distractors are phonologically related to the target (e.g., tiger-typist) than when they are unrelated. By varying the position of overlap of the shared phonemes and the onset of the distractor, this task may provide valuable insights into the time course of phonological encoding. In the current study, participants named pictures while hearing distractor words that were: begin-related (e.g., letter-lesson); end-related (e.g., letter-otter); or unrelated to the target (e.g., letter-cabin). Distractor onsets varied from -200ms (before target) to +400ms (after target). The study was carried out in two phases: in the first phase, the task was administered to a group of 24 young control participants; in the second phase, it was administered to an individual with aphasia, NP, and a group of six older controls. Phonological facilitation effects of begin-related distractors displayed a fairly consistent pattern across the four distractor onsets for all participant groups. In almost all instances, these effects were significant but were noticeably stronger at early onsets especially around the onset of the target presentation, consistent with previous findings in the literature. Only NP showed strong begin-related facilitation effects at the latest onset. The end-related distractors however, produced somewhat different facilitation effects across the different groups. For the young controls and NP, these effects were stronger and significant at later onsets. The older controls only displayed marginally significant effects at 200ms after the target. Findings from the current study provide support for serial pattern of phoneme retrieval in multisyllabic words, in which a word‟s first syllable becomes available before later syllable(s).