Cue Competition During Phonotactic Processing in Bilingual Adults as Measured by Eye-Tracking

It is well documented in the literature that bilingual speakers simultaneously activate both languages during spoken language processing (e.g., Marian & Spivey, 2003). However, parallel activation can lead to competition between the two languages (e.g., Blumenfield & Marian, 2013; Freeman, Shook, & Marian, 2016). The Unified Competition model (UCM) provides a theory as to how bilingual speakers navigate through two languages while different linguistic cues are competing (MacWhinney, 2005). The UCM proposes that cues are used to process language, based on cue validity (the product of how reliable and available a cue is), which is determined by cue strength (a measure based on conflict reliability; how reliable a cue is when it directly conflicts with others). Two likely cues bilingual speakers use while processing a novel spoken word are linguistic environment (the language being spoken around them) and phonotactic probability (the probability of the sounds making up a novel word). Applying the theory of the UCM this study sets to answer the following general question: How do Spanish/English bilingual adults assign language membership to nonwords when linguistic environment and phonotactic cues are competing? The current study consisted of twenty-two Spanish/English adults who listened to 96 nonwords that corresponded to three different groups based on phonotactic probability: Language Exclusive (the phonotactics of the nonwords designated them as either Spanish only or English only), High-Low (the nonwords had high phonotactic probability in one language and low probability in the other), and Ambiguous (the nonowords had similar phonotactic probability in both languages). The participants were tested in one of two linguistic environments (primarily English with some Spanish code-switching or primarily Spanish with some English code-switching) and partook in a two-alternative forced choice listening test (participants determined if each nonword was either Spanish or English). The language membership decision was measured via verbal response and eye-tracking using EyeLink 1000 Plus measuring eye gaze, number of fixations and switches. In general, results indicated that Spanish/English bilingual adults relied only on phonotactic probability when making language membership decisions, but not as strongly as may be suggested by the UCM. The results of this study suggest that environmental cues are not strong enough to impact spoken language processing in Spanish/English bilingual adults and that phonotactic probability is likely a more easily accessible (and therefore more commonly used) cue