The role of memory and representations in statistical learning

Abstract

Numerous studies have examined learners’ ability to track auditory statistical cues (e.g., Saffran, Aslin, and Newport, 1996). It remains unknown, however, how learners manage this feat. This concern is non-trivial: computation of the transitional probabilities in a traditional statistical learning task would involve access to (at least) hundreds of memory traces that have been accumulated over a mere two minutes. The present experiments aim to elucidate the mechanisms underlying statistical learning. Adult participants are exposed to a 2-min continuous speech stream, composed of native phonetic units (study 1), semi-native phonetic units (study 2), or non-native phonetic units (study 3). Participants’ memories for words are then tested through forced-choice comparisons of words, part-words, and phantom words. In study 1, participants successfully segmented the native phonetic speech stream; however, they showed no preference for part-words or phantom words. Furthermore, asymmetries in performance by syllable position (onset, medial, coda) suggest that memory for the segmented words may be more specified/stable in the medial and coda positions. Preliminary results from study 3 (non-native) suggest that participants fail to segment the stream of less familiar sounds. Taken together, these results suggest that statistical learning proceeds via a “chunking”-type mechanism (e.g., Perruchet and Vinter, 1998).