Distant Melodies: Statistical Learning of Nonadjacent Dependencies in Tone Sequences.

Abstract
Human listeners can keep track of statistical regularities among temporally adjacent elements in both speech and musical streams. However, for speech streams, when statistical regularities occur among nonadjacent elements, only certain types of patterns are acquired. Here, using musical tone sequences, the authors investigate nonadjacent learning. When the elements were all similar in pitch range and timbre, learners acquired moderate regularities among adjacent tones but did not acquire highly consistent regularities among nonadjacent tones. However, when elements differed in pitch range or timbre, learners acquired statistical regularities among the similar, but temporally nonadjacent, elements. Finally, with a moderate grouping cue, both adjacent and nonadjacent statistics were learned, indicating that statistical learning is governed not only by temporal adjacency but also by Gestalt principles of similarity. How do listeners organize and learn a patterned sequence of elements? Recent studies of a mechanism we have called statisti- cal learning have shown that adults, young children, and infants are capable of computing transitional probabilities among adjacent syllables in rapidly presented streams of speech and of using these statistics to group syllables into word-like units (Aslin, Saffran, & Newport, 1998; Saffran, Aslin, & Newport, 1996; Saffran, New-