Reconciling phonological neighborhood effects in speech production through single trial analysis

A crucial step for understanding how lexical knowledge is represented is to describe the relative similarity of lexical items, and how it influences language processing. Previous studies of the effects of form similarity on word production have reported conflicting results, notably within and across languages. The aim of the present study was to clarify this empirical issue to provide specific constraints for theoretical models of language production. We investigated the role of phonological neighborhood density in a large-scale picture naming experiment using fine-grained statistical models. The results showed that increasing phonological neighborhood density has a detrimental effect on naming latencies, and re-analyses of independently obtained data sets provide supplementary evidence for this effect. Finally, we reviewed a large body of evidence concerning phonological neighborhood density effects in word production, and discussed the occurrence of facilitatory and inhibitory effects in accuracy measures. The overall pattern shows that phonological neighborhood generates two opposite forces, one facilitatory and one inhibitory. In cases where speech production is disrupted (e.g. certain aphasic symptoms), the facilitatory component may emerge, but inhibitory processes dominate in efficient naming by healthy speakers. These findings are difficult to accommodate in terms of monitoring processes, but can be explained within interactive activation accounts combining phonological facilitation and lexical competition.This research was supported by a grant from the European Research Council under the European Community’s Seventh Framework Program (FP7/2007-2013 Grant agreement n◦ 263575), three grants from the Spanish government (PSI2008-01191, PSI2011-23033, Consolider Ingenio 2010 CSD2007-00012), and the Catalan government (Consolidado SGR 2009-1521)

Speech-Sign Bilingualism

Summary Bilingualism provides a unique window into language processing and its underlying neurocognitive mechanisms. This chapter focuses on bilinguals who know both a signed and spoken language (speech-sign bilinguals). It compiles and interprets the findings that relate to speech-sign bilingualism in the brain. The chapter provides an overview of the relevant research to date placed in a wider language context by extending the study of bilingualism to languages in two different sensorimotor modalities, but at the same time focusing on results that provide critical insight into multilingualism more broadly. The cognitive demands on lexical processing may be higher for speech-sign bilinguals compared with monolinguals as, similarly to spoken-language bilinguals, speech-sign bilinguals must represent two sets of lexical items. Finally, long-term cognitive benefits in terms of grey matter volume have been attributed to bilinguals. Specifically, an increased grey matter volume in brain areas underpinning executive control has been identified as a beneficial neural change of bilingualism