DOI: 10.23641/asha.5435137
title: Consonant age-of-acquisition effects in nonword repetition (Moore et al., 2017)

description: <b>Purpose:</b> Most research examining long-term-memory effects on nonword repetition (NWR) has focused on lexical-level variables. Phoneme-level variables have received little attention, although there are reasons to expect significant sublexical effects in NWR. To further understand the underlying processes of NWR, this study examined effects of sublexical long-term phonological knowledge by testing whether performance differs when the stimuli comprise consonants acquired later versus earlier in speech development.<b>Method:</b> Thirty (Experiment 1) and 20 (Experiment 2) college students completed tasks that investigated whether an experimental phoneme-level variable (consonant age of acquisition) similarly affects NWR and lexical-access tasks designed to vary in articulatory, auditory-perceptual, and phonological short-term-memory demands. The lexical-access tasks were performed in silence or with concurrent articulation to explore whether consonant age-of-acquisition effects arise before or after articulatory planning.<b>Results: </b>NWR accuracy decreased on items comprising later- versus earlier-acquired phonemes. Similar consonant age-of-acquisition effects were observed in accuracy measures of nonword reading and lexical decision performed in silence or with concurrent articulation.<b>Conclusion:</b> Results indicate that NWR performance is sensitive to phoneme-level phonological knowledge in long-term memory. NWR, accordingly, should not be regarded as a diagnostic tool for pure impairment of phonological short-term memory.<br><b>Supplemental Material S1. </b>Nonword repetition stimuli from Experiment 1.<br><b>Supplemental Material S2.</b> Nonword repetition summary statistics of the stimuli characteristics using independent sample <i>t</i> tests.<br><b>Supplemental Material S3.</b> Nonword reading stimuli from Experiment 1.<br><b>Supplemental Material S4.</b> Nonword reading summary statistics of the stimuli characteristics using independent sample <i>t</i> tests.<br><b>Supplemental Material S5. </b>Auditory lexical decision stimuli from Experiment 1.<br><b>Supplemental Material S6. </b>Auditory lexical decision (Experiment 1) summary statistics of the stimuli characteristics using independent sample <i>t </i>tests.<br><b>Supplemental Material S7</b>. Word and nonword stimuli for List 1 of the lexical decision task in Experiment 2.<b><br></b><b>Supplemental Material S8. </b>Word and nonword stimuli for List 2 of the lexical decision task in Experiment 2.<br><b>Supplemental Material S9.</b> Word and nonword stimuli for List 3 of the lexical decision task in Experiment 2.<br><b>Supplemental Material S10.</b> Word and nonword stimuli for List 4 of the lexical decision task in Experiment 2.<br><b>Supplemental Material S11.</b> Summary statistics of the Experiment 2 nonword stimuli characteristics using 2 × 4 (Phoneme Type × List) analyses of variance (ANOVAs).<br><b>Supplemental Material S12.</b> Summary statistics of the Experiment 2 word stimuli characteristics using 2 × 4 (Phoneme Type × List) analyses of variance (ANOVAs).<br>Moore, M. W., Fiez, J. A., & Tompkins, C. A. (2017). Consonant age-of-acquisition effects in nonword repetition are not articulatory in nature. <i>Journal of Speech, Language, and Hearing Research, 60, </i>3198–3212<i>. </i>https://doi.org/10.1044/2017_JSLHR-L-16-0359<br>