Effects of Phonological Neighbourhood Density and Frequency in Mono-and Bilingual Speakers with Aphasia Megan Palmer1, Britta Biedermann1,2* (presenter), Solène Hameau2, Anne Whitworth1, Lyndsey Nickels2 1Faculty of Health Sciences, Curtin University, Australia; 2ARC Centre of Excellence for Cognition and its Disorders, Department of Cognitive Science, Macquarie University, Australia When a bilingual is speaking in one language, words of the other (non-target) language are activated1. However, there has been little investigation of whether similar sounding words in the non-target language (cross-language phonological neighbours) influence production. Findings to date are inconsistent, with no effects, or facilitatory effects of phonological neighbourhood density (PND) for unimpaired bilingual speakers 2;3;4. No research has examined bilingual speakers with aphasia (BwA), but findings for monolingual speakers with aphasia (MwA) show that high PND can result in overall better accuracy5, fewer omission errors6, and/or more articulatory errors7. However, phonological neighborhood frequency (PNF) has not been controlled for in most studies and therefore may be an overlooked variable that could account for some of the inconsistent evidence. This study aimed to extend the investigation of the influence of PND and PNF to BwA, while collecting further evidence for MwA, using a case series design8:9. One Italian-English BwA, who showed equal proficiency pre-morbidly for both languages, and three Australian-English MwA participated; all of whom presented with spoken word finding difficulties but preserved comprehension (stroke onset > 1 year). Participants were required to name 244 pictures10 of objects with high cross-linguistic name agreement (> 85%). Responses were used to examine latency, accuracy and error type, using within- and, for the BwA, across-language PND and PNF as predictor variables (calculated using CLEARPOND11), while controlling for log frequency, number of phonemes, imageability, age-of-acquisition, and visual complexity. Logistic and multiple regressions indicated that PND and PNF had no significant effect for MwA (all ps >.1). A facilitatory trend was observed for the BwA, showing a marginal within-language effect for PNF in English (p = .07), and for PND in Italian (p = .056). Cross-language PND and PNF effects were not observed (p >.1). Theoretical implications will be discussed in current production models1;12. References 1. Costa, A., La Heij, W., & Navarrete, E. (2006). The dynamics of bilingual lexical access. Bilingualism: Language and Cognition, 9(2), 137-151. 2. Sadat, J., Martin, C. D., Magnuson, J. S., Alario, F. X., & Costa, A. (2016). Breaking down the bilingual cost in speech production. Cognitive science, 40(8), 1911-1940. 3. Gahl, S., & Strand, J. F. (2016). Many neighborhoods: Phonological and perceptual neighborhood density in lexical production and perception. Journal of Memory and Language, 89, 162-178. 4. Marian, V., & Blumenfeld, H. (2006). Phonological neighborhood density guides lexical access in native and non-native language production. Journal of Social and Ecological Boundaries, 2, 3-35. 5. Best, W. (1995). A reverse length effect in dysphasic naming: When elephant is easier than ant. Cortex, 31(4), 637-652. 6. Dell, G.S., Schwartz, M.F., Martin, N., Saffran, E.M., & Gagnon, D.A. (2000). The role of computational models in the cognitive neuropsychology of language: Reply to Ruml and Caramazza. Psychological Review, 107, 635-645. 7. Laganaro, M., Chetelat-Mabillard, D., & Frauenfelder, U. H. (2013). Facilitatory and interfering effects of neighbourhood density on speech production: Evidence from aphasic errors. Cognitive neuropsychology, 30(3), 127-146. 8. Nickels, L., Best, W., & Howard, D. (2015). Optimising the ingredients for evaluation of the effects of intervention. Aphasiology, 29(5), 619-643. 9. Schwartz, M. F., & Dell, G. S. (2010). Case series investigations in cognitive neuropsychology. Cognitive neuropsychology, 27(6), 477-494. 10. Duñabeitia, J. A., Crepaldi, D., Meyer, A. S., New, B., Pliatsikas, C., Smolka, E., & Brysbaert, M. (2017). MultiPic: A standardized set of 750 drawings with norms for six European languages. The Quarterly Journal of Experimental Psychology, (just-accepted), 1-24. 11. Marian, V., Bartolotti, J., Chabal, S., & Shook, A. (2012). CLEARPOND: Cross-linguistic easy-access resource for phonological and orthographic neighborhood densities. PloS one, 7(8), e43230. 12. Dell, G.S., Schwartz, M.F., Martin, N., Saffran, E.M., & Gagnon, D.A. (1997). Lexical access in aphasic and nonaphasic speakers. Psychological Review, 104, 801-838.