Segmental information drives adult bilingual phrase segmentation preference

In two artificial language learning experiments with four groups of highly proficient Basque-Spanish bilinguals and two groups of Spanish monolinguals, we examine the cues that allow adult listeners to parse new input into phrases. In addition, we investigate which factors lead bilinguals to switch between the segmentation strategies characteristic of their two languages. We show that segmental information drives bilinguals’ choice of a segmentation strategy when presented with an unfamiliar language. The language in which bilinguals are addressed during the study (i.e. the language of context) additionally modulates their segmentation preference, and this context language effect is found in L1Basque bilinguals but does not extend to L1Spanish bilinguals. The cause of this asymmetry is yet to be established. Finally, we show that adult monolinguals disregard statistical cues in favor of unfamiliar segmental information when in conflict. These results evidence that the available phrase segmentation cues are arranged hierarchically.