Use of Word Segmentation Cues in Adults: L1 Phonotactics versus L2 Transitional Probabilities

We investigate whether adult learners’ knowledge of phonotactic restrictions on word forms from their first language (L1) impact their word segmentation abilities in a new language. Adult learners were exposed to a speech stream in which language specific and non-language specific cues for word segmentation were pitted against one another. English rules about possible phonetic combinations (phonotactics) and transitional probabilities of syllables conflicted such that predictive transitional probabilities generated words that were phonotactically impossible in English. A control with phonotactically viable items was also run. At test, participants choose between words defined by deterministic transitional probabilities and words that are phonotactically possible in English, but have much lower transitional probabilities. A baseline of their abilities to track transitional probabilities in the stimuli was also collected. Results suggest that although participants are able to track the transitional probabilities in these stimuli, they are not using them to segment and extract words. Control subjects, however, do use transitional probabilities to segment words. This pattern of results is resilient, holding up with substantial increases in exposure and even when segmentation is encouraged by explicitly giving participants one of the words in the stream prior to exposure.