Novel phonotactic learning by children and infants: Generalizing syllable-position but not co-occurrence regularities.

Restrictions in the sequencing of sounds (phonotactic constraints) can be represented at the level of sound co-occurrences (e.g., in baF.Pev, F and P co-occur) and at the level of the syllable (e.g., F is syllable-coda/end, P is syllable-onset/start). Can children (5-year-olds) and infants (11-month-olds) represent constraints as sound co-occurrences and/or relative to syllable positions? Participants listened to artificial languages displaying both word-medial consonant restrictions in co-occurrence pairs (e.g., FP or DZ but not FZ) and in the position of consonants within syllables (e.g., P/Z onsets and D/F codas) in words like baF.Pev and tiD.Zek. Children responded similarly to novel words with the same (e.g., FP) versus different (e.g., FZ) co-occurrence pairs, but they were more misled (i.e., responded "heard it before") by novel words with consonants in the same (e.g., onset-P) versus different (e.g., coda-P) syllable positions (Experiment 1). With the same training stimuli, infants had similar orientation times for novel words with the same versus different co-occurrence pairs, but they had longer orientation times for novel words with consonants in the same versus different syllable positions (Experiment 2). Thus, across different methods and ages, syllable-position information was more readily available for generalization than consonant co-occurrence information. The results suggest that when multiple regularities are present simultaneously, some phonotactic constraints (e.g., consonants in particular syllable positions) may be spontaneously represented and generalized by children and infants, whereas others (e.g., consonant co-occurrences) might not be available. The results contribute toward understanding how children and infants represent sound sequences.

Novel stress phonotactics are learnable by English speakers: Novel tone phonotactics are not.

Speech errors are sensitive to newly learned phonotactic constraints. For example, if speakers produce strings of syllables in which /f/ is an onset if the vowel is /æ/, but a coda if the vowel is /I/, their slips will respect that constraint after a period of sleep. Constraints in which the contextual factor is nonlinguistic, however, do not appear to be learnable by this method-for example, /f/ is an onset if the speech rate is fast, but /f/ is a coda if the speech rate is slow. The present study demonstrated that adult English speakers can learn (after a sleep period) constraints based on stress (e.g., /f/ is an onset if the syllable is stressed, but /f/ is a coda if the syllable is unstressed), but cannot learn analogous constraints based on tone (e.g., /f/ is an onset if the tone is rising, but /f/ is a coda if the tone is falling). The results are consistent with the fact that, in English, stress is a relevant lexical phonological property (e.g., "INsight" and "inCITE" are different words), but tone is not (e.g., "yes!" and "yes?" are the same word, despite their different pragmatic functions). The results provide useful constraints on how consolidation effects in learning may interact with early learning experiences.

Multiple Sources of Surprisal Affect Illusory Vowel Epenthesis.

Illusory epenthesis is a phenomenon in which listeners report hearing a vowel between a phonotactically illegal consonant cluster, even in the complete absence of vocalic cues. The present study uses Japanese as a test case and investigates the respective roles of three mechanisms that have been claimed to drive the choice of epenthetic vowel-phonetic minimality, phonotactic predictability, and phonological alternations-and propose that they share the same rational goal of searching for the vowel that minimally alters the original speech signal. Additionally, crucial assumptions regarding phonological knowledge held by previous studies are tested in a series of corpus analyses using the Corpus of Spontaneous Japanese. Results show that all three mechanisms can only partially account for epenthesis patterns observed in language users, and the study concludes by discussing possible ways in which the mechanisms might be integrated.

Listeners learn phonotactic patterns conditioned on suprasegmental cues.

Language learners are sensitive to phonotactic patterns from an early age, and can acquire both simple and 2nd-order positional restrictions contingent on segment identity (e.g., /f/ is an onset with /æ/but a coda with /ɪ/). The present study explored the learning of phonototactic patterns conditioned on a suprasegmental cue: lexical stress. Adults first heard non-words in which trochaic and iambic items had different consonant restrictions. In Experiment 1, participants trained with phonotactic patterns involving natural classes of consonants later falsely recognized novel items that were consistent with the training patterns (legal items), demonstrating that they had learned the stress-conditioned phonotactic patterns. However, this was only true for iambic items. In Experiment 2, participants completed a forced-choice test between novel legal and novel illegal items and were again successful only for the iambic items. Experiment 3 demonstrated learning for trochaic items when they were presented alone. Finally, in Experiment 4, in which the training phase was lengthened, participants successfully learned both sets of phonotactic patterns. These experiments provide evidence that learners consider more global phonological properties in the computation of phonotactic patterns, and that learners can acquire multiple sets of patterns simultaneously, even contradictory ones.

Phonological Concept Learning.

Linguistic and non-linguistic pattern learning have been studied separately, but we argue for a comparative approach. Analogous inductive problems arise in phonological and visual pattern learning. Evidence from three experiments shows that human learners can solve them in analogous ways, and that human performance in both cases can be captured by the same models. We test GMECCS (Gradual Maximum Entropy with a Conjunctive Constraint Schema), an implementation of the Configural Cue Model (Gluck & Bower, ) in a Maximum Entropy phonotactic-learning framework (Goldwater & Johnson, ; Hayes & Wilson, ) with a single free parameter, against the alternative hypothesis that learners seek featurally simple algebraic rules ("rule-seeking"). We study the full typology of patterns introduced by Shepard, Hovland, and Jenkins () ("SHJ"), instantiated as both phonotactic patterns and visual analogs, using unsupervised training. Unlike SHJ, Experiments 1 and 2 found that both phonotactic and visual patterns that depended on fewer features could be more difficult than those that depended on more features, as predicted by GMECCS but not by rule-seeking. GMECCS also correctly predicted performance differences between stimulus subclasses within each pattern. A third experiment tried supervised training (which can facilitate rule-seeking in visual learning) to elicit simple rule-seeking phonotactic learning, but cue-based behavior persisted. We conclude that similar cue-based cognitive processes are available for phonological and visual concept learning, and hence that studying either kind of learning can lead to significant insights about the other.

Novel phonotactic learning: Tracking syllable-position and co-occurrence constraints.

Are syllable-level and co-occurrence representations simultaneously available when one learns novel phonotactics? After training on word-medial consonant restrictions (e.g., word-medial onsets P/Z, codas D/F, and cross-syllable consonant clusters FP/DZ in items like baF.Pev, tiD.Zek), adults falsely recognized novel items containing restricted consonants with the same co-occurrences (e.g., FP) more often than those with different co-occurrences (e.g., FZ) when syllable-position information was kept constant (e.g., vuF.Pet vs. vuF.Zet; Experiment 1). Thus, adults tracked co-occurrence information. Additionally, even when co-occurrence information was different from training, participants more often falsely recognized novel items that contained restricted consonants in the same (e.g., onset-Z) rather than different syllable positions (e.g., coda-Z), whether the restricted consonants were in the same (word-medial, e.g., vuF.Zet vs. vuZ.Fet, Experiment 2) or different word positions (word-edge, e.g., Zut.veF vs. Fut.veZ, Experiment 3). Thus, adults also tracked syllable-level information. These findings show that adults spontaneously represent sound sequences at multiple levels.

An onset is an onset: Evidence from abstraction of newly-learned phonotactic constraints.

Phonotactic constraints are language-specific patterns in the sequencing of speech sounds. Are these constraints represented at the syllable level (ng cannot begin syllables in English) or at the word level (ng cannot begin words)? In a continuous recognition-memory task, participants more often falsely recognized novel test items that followed than violated the training constraints, whether training and test items matched in word structure (one or two syllables) or position of restricted consonants (word-edge or word-medial position). E.g., learning that ps are onsets and fs codas, participants generalized from pef (one syllable) to putvif (two syllables), and from putvif (word-edge positions) to bufpak (word-medial positions). These results suggest that newly-learned phonotactic constraints are represented at the syllable level. The syllable is a representational unit available and spontaneously used when learning speech-sound constraints. In the current experiments, an onset is an onset and a coda a coda, regardless of word structure or word position.