Generalization to Novel Consonants: Place Versus Voice.

In traditional, generative phonology, sound patterns are represented in terms of abstract features, typically based on the articulatory properties of the sounds. The present study makes use of an artificial language learning experiment to explore when and how learners extend a novel phonological pattern to novel segments. Adult, English-speaking learners were exposed to a spirantization pattern in which a stop became a fricative between two vowels (e.g., /bib/ + /o/ ➔ [bivo]). Participants were trained on spirantization for two of four possible stop-fricative pairs, and were tested on their generalization to the held-out segments. Two groups of participants were trained on items based on voicing (e.g., the Voiced condition was trained on /b/ ➔ [v], and /d/ ➔ [z], and tested on /p/ ➔ [f], and /t/ ➔ [s]), and two groups of participants were trained on items based on place of articulation (e.g., the Labial condition was trained on /b/ ➔ [v], and /p/ ➔ [f] and tested on /t/ ➔ [s], and /d/ ➔ [z]). Participants in both Place and Voice conditions were successful at learning and generalizing the spirantization pattern to novel segments, but rates of generalization were higher in the Voice conditions. These results support a similarity-based approach to generalization, particularly one that takes into account articulatorily-based features and natural classes. Implications for phonological theory are discussed.

Learning Exceptions in Phonological Alternations.

The present study explores learning phonological alternations that contain exceptions. Participants were exposed to a back/round vowel harmony pattern in which a regular suffix obeyed a vowel harmony rule, varying between /e/ and /o/ depending on the back/round phonetic features of the stem, and a non-alternating suffix that was always /o/ regardless of the features of the stem vowel. Participants in Experiment 1 learned the behavior of both suffixes, but correct performance for the non-alternating suffix was higher when the suffix happened to be in harmony with the stem. Participants in Experiment 2 were exposed to the non-alternating affix in harmonic contexts only, and continued to show a bias towards harmony. Experiment 3 replicated Experiment 2 with minimal training on disharmonic cases of the non-alternating morpheme. However, participants were less likely to learn the alternating affix without exposure to morphological stem, stem + suffix alternations in Experiment 4, suggesting a bias towards morphophonological alternations in learning vowel harmony patterns.

Cognitive and linguistic biases in morphology learning.

Morphology is the study of the relationship between form and meaning. The study of morphology involves understanding the rules and processes that underlie word formation, including the use and productivity of affixes, and the systems that create novel word forms. The present review explores these processes by examining the cognitive components that contribute to typological regularities among morphological systems across the world's language. The review will focus on research in morpheme segmentation, the suffixing preference, acquisition of morphophonology, and acquiring morphological categories and inflectional paradigms. The review will highlight research in a range of areas of linguistics, from child language acquisition, to computational modeling, to adult language learning experiments. In order to best understand the cognitive biases that shape morphological learning, a broad, interdisciplinary approach must be taken. This article is categorized under: Linguistics > Linguistic Theory Linguistics > Language Acquisition Psychology > Language.

Learning metathesis: Evidence for syllable structure constraints.

One of the major questions in the cognitive science of language is whether the perceptual and phonological motivations for the rules and patterns that govern the sounds of language are a part of the psychological reality of grammatical representations. This question is particularly important in the study of phonological patterns - systematic constraints on the representation of sounds, because phonological patterns tend to be grounded in phonetic constraints. This paper focuses on phonological metathesis, which occurs when two adjacent sounds switch positions (e.g., cast pronounced as cats ). While many cases of phonological metathesis appear to be motivated by constraints on syllable structure, it is possible that these metathesis patterns are merely artifacts of historical change, and do not represent the linguistic knowledge of the speaker (Blevins & Garrett, 1998). Participants who were exposed to a metathesis pattern that can be explained in terms of structural or perceptual improvement were less likely to generalize to metathesis patterns that did not show the same improvements. These results support a substantively biased theory in which phonological patterns are encoded in terms of structurally motivated constraints.

LEARNING NONADJACENT DEPENDENCIES IN PHONOLOGY: TRANSPARENT VOWELS IN VOWEL HARMONY.

Nonadjacent dependencies are an important part of the structure of language. While the majority of syntactic and phonological processes occur at a local domain, there are several processes that appear to apply at a distance, posing a challenge for theories of linguistic structure. This article addresses one of the most common nonadjacent phenomena in phonology: transparent vowels in vowel harmony. Vowel harmony occurs when adjacent vowels are required to share the same phonological feature value (e.g. V+F C V+F). However, transparent vowels create a second-order nonadjacent pattern because agreement between two vowels can 'skip' the transparent neutral vowel in addition to consonants (e.g. V+F C VT-F C V+F). Adults are shown to display initial learning biases against second-order nonadjacency in experiments that use an artificial grammar learning paradigm. Experiments 1-3 show that adult learners fail to learn the second-order long-distance dependency created by the transparent vowel (as compared to a control condition). In experiments 4-5, training in terms of overall exposure as well as the frequency of relevant transparent items was increased. With adequate exposure, learners reliably generalize to novel words containing transparent vowels. The experiments suggest that learners are sensitive to the structure of phonological representations, even when learning occurs at a relatively rapid pace.

Generalization to unfamiliar talkers in artificial language learning.

While there is evidence that talker-specific details are encoded in the phonetics of the lexicon (Kraljic, Samuel, & Brennan, Psychological Science 19(4):332-228, 2008; Logan, Lively, & Pisoni, Journal of the Acoustical Society of America, 89(2):874-886, 1991) and in sentence processing (Nygaard & Pisoni, Perception & Psychophysics, 60(3):355-376, 1998), it is unclear whether categorical linguistic patterns are also represented in terms of talker-specific details. The present study provides evidence that adult learners form talker-independent representations for productive linguistic patterns. Participants were able to generalize a novel linguistic pattern to unfamiliar talkers. Learners were exposed to spoken words that conformed to a pattern in which vowels of a word agreed in place of articulation, referred to as vowel harmony. All items were presented in the voice of one single talker. Participants were tested on items that included both the familiar talker and an unfamiliar talker. Participants generalized the pattern to novel talkers when the talkers spoke with a familiar accent (Experiment 1), as well as with an unfamiliar accent (Experiment 2). Learners showed a small advantage for talker familiarity when the words were familiar, but not when the words were novel. These results are consistent with a theory of language processing in which the lexicon stores fine-grained, talker-specific phonetic details, but productive linguistic processes are subject to abstract, talker-independent representations.

Typological Asymmetries in Round Vowel Harmony: Support from Artificial Grammar Learning.

Providing evidence for the universal tendencies of patterns in the world's languages can be difficult, as it is impossible to sample all possible languages, and linguistic samples are subject to interpretation. However, experimental techniques such as artificial grammar learning paradigms make it possible to uncover the psychological reality of claimed universal tendencies. This paper addresses learning of phonological patterns (systematic tendencies in the sounds in language). Specifically, I explore the role of phonetic grounding in learning round harmony, a phonological process in which words must contain either all round vowels ([o, u]) or all unround vowels ([i, e]). The phonetic precursors to round harmony are such that mid vowels ([o, e]), which receive the greatest perceptual benefit from harmony, are most likely to trigger harmony. High vowels ([i, u]), however, are cross-linguistically less likely to trigger round harmony. Adult participants were exposed to a miniature language that contained a round harmony pattern in which the harmony source triggers were either high vowels ([i, u]) (poor harmony source triggers) or mid vowels ([o, e]) (ideal harmony source triggers). Only participants who were exposed to the ideal mid vowel harmony source triggers were successfully able to generalize the harmony pattern to novel instances, suggesting that perception and phonetic naturalness play a role in learning.

Testing the limits of long-distance learning: learning beyond a three-segment window.

Traditional flat-structured bigram and trigram models of phonotactics are useful because they capture a large number of facts about phonological processes. Additionally, these models predict that local interactions should be easier to learn than long-distance ones because long-distance dependencies are difficult to capture with these models. Long-distance phonotactic patterns have been observed by linguists in many languages, who have proposed different kinds of models, including feature-based bigram and trigram models, as well as precedence models. Contrary to flat-structured bigram and trigram models, these alternatives capture unbounded dependencies because at an abstract level of representation, the relevant elements are locally dependent, even if they are not adjacent at the observable level. Using an artificial grammar learning paradigm, we provide additional support for these alternative models of phonotactics. Participants in two experiments were exposed to a long-distance consonant-harmony pattern in which the first consonant of a five-syllable word was [s] or [∫] ("sh") and triggered a suffix that was either [-su] or [-∫u] depending on the sibilant quality of this first consonant. Participants learned this pattern, despite the large distance between the trigger and the target, suggesting that when participants learn long-distance phonological patterns, that pattern is learned without specific reference to distance.

The privileged status of locality in consonant harmony.

While the vast majority of linguistic processes apply locally, consonant harmony appears to be an exception. In this phonological process, consonants share the same value of a phonological feature, such as secondary place of articulation. In sibilant harmony, [s] and [ʃ] ('sh') alternate such that if a word contains the sound [ʃ], all [s] sounds become [ʃ]. This can apply locally as a first-order or non-locally as a second-order pattern. In the first-order case, no consonants intervene between the two sibilants (e.g., [pisasu], [piʃaʃu]). In second-order case, a consonant may intervene (e.g., [sipasu], [ʃipaʃu]). The fact that there are languages that allow second-order non-local agreement of consonant features has led some to question whether locality constraints apply to consonant harmony. This paper presents the results from two artificial grammar learning experiments that demonstrate the privileged role of locality constraints, even in patterns that allow second-order non-local interactions. In Experiment 1, we show that learners do not extend first-order non-local relationships in consonant harmony to second-order nonlocal relationships. In Experiment 2, we show that learners will extend a consonant harmony pattern with second-order long distance relationships to a consonant harmony with first-order long distance relationships. Because second-order non-local application implies first-order non-local application, but first-order non-local application does not imply second-order non-local application, we establish that local constraints are privileged even in consonant harmony.