Kristine H. Onishi

Infants learn phonotactic regularities from brief auditory experience

Two experiments investigated whether novel phonotactic regularities, not present in English, could be acquired by 16.5-month-old infants from brief auditory experience. Subjects listened to consonant-vowel-consonant syllables in which particular consonants were artificially restricted to either initial or final position (e.g. /baep/ not /paeb/). In a later head-turn preference test, infants listened longer to new syllables that violated the experimental phonotactic constraints than to new syllables that honored them. Thus, infants rapidly learned phonotactic regularities from brief auditory experience and extended them to unstudied syllables, documenting the sensitivity of the infants language processing system to abstractions over linguistic experience.

Persistent structural priming from language comprehension to language production

To examine the relationship between syntactic processes in language comprehension and language production, we compared structural persistence from sentence primes that speakers heard to persistence from primes that speakers produced. [Bock, J. K., & Griffin, Z. M. (2000). The persistence of structural priming: transient activation or implicit learning? Journal of Experimental Psychology: General, 129, 177-192.] showed that the production of target priming structures increased the probability of spontaneously using the same structures to describe events in subsequent pictures that were semantically unrelated to the primes. These priming effects persisted across as many as ten intervening filler trials. The present studies replicated these results using auditorily presented primes to which participants only listened. The results indicated persistence of priming across all lags, with relative magnitudes of priming as large as those observed by Bock and Griffin. The implication is that structural priming is persistent regardless of the modality in which language structures are experienced, underscoring the power of priming as an implicit learning mechanism.

Learning phonotactic constraints from brief auditory experience

Three experiments asked whether phonotactic regularities not present in English could be acquired by adult English speakers from brief listening experience. Subjects listened to consonant-vowel-consonant (CVC) syllables displaying restrictions on consonant position. Responses in a later speeded repetition task revealed rapid learning of (a) first-order regularities in which consonants were restricted to particular positions (e.g. [baep] not *[paeb]), and (b) second-order regularities in which consonant position depended on the adjacent vowel (e.g. [baep] or [pIb], not *[paeb] or *[bIp]). No evidence of learning was found for second-order regularities in which consonant position depended on speakers voice. These results demonstrated that phonotactic constraints are rapidly learned from listening experience and that some types of contingencies (consonant-vowel) are more easily learned than others (consonant-voice).

Comparing online and lab methods in a problem-solving experiment

Online experiments have recently become very popular, and—in comparison with traditional lab experiments— they may have several advantages, such as reduced demand characteristics, automation, and generalizability of results to wider populations (Birnbaum, 2004; Reips, 2000, 2002a, 2002b). We replicated Dandurand, Bowen, and Shultz’s (2004) lab-based problem-solving experiment as an Internet experiment. Consistent with previous results, we found that participants who watched demonstrations of successful problem-solving sessions or who read instructions outperformed those who were told only that they solved problems correctly or not. Online participants were less accurate than lab participants, but there was no interaction with learning condition. Thus, we conclude that online and Internet results are consistent. Disadvantages included high dropout rate for online participants; however, combining the online experiment with the department subject pool worked well.

Allophonic and Phonemic Contrasts in Infants' Learning of Sound Patterns

French-learning 11-month-old and English-learning 11- and 4-month-old infants were familiarized with consonant–vowel–consonant syllables in which the final consonants were dependent on whether the preceding vowel was oral or nasal. Oral and nasal vowels are present in the ambient language of all participants, but vowel nasality is phonemic (contrastive) in French and allophonic (noncontrastive) in English. After familiarization, infants heard novel syllables that either followed or violated the familiarized patterns. French-learning 11-month-olds and English-learning 4-month-olds displayed a reliable pattern of preference demonstrating learning and generalization of the patterns, while English-learning 11-month-olds oriented equally to syllables following and violating the familiarized patterns. The results are consistent with an experience-driven reduction of attention to allophonic contrasts by as early as 11 months, which influences phonotactic learning.

Twelve-month-old infants recognize that speech can communicate unobservable intentions

Much of our knowledge is acquired not from direct experience but through the speech of others. Speech allows rapid and efficient transfer of information that is otherwise not directly observable. Do infants recognize that speech, even if unfamiliar, can communicate about an important aspect of the world that cannot be directly observed: a person’s intentions? Twelve-month-olds saw a person (the Communicator) attempt but fail to achieve a target action (stacking a ring on a funnel). The Communicator subsequently directed either speech or a nonspeech vocalization to another person (the Recipient) who had not observed the attempts. The Recipient either successfully stacked the ring (Intended outcome), attempted but failed to stack the ring (Observable outcome), or performed a different stacking action (Related outcome). Infants recognized that speech could communicate about unobservable intentions, looking longer at Observable and Related outcomes than the Intended outcome when the Communicator used speech. However, when the Communicator used nonspeech, infants looked equally at the three outcomes. Thus, for 12-month-olds, speech can transfer information about unobservable aspects of the world such as internal mental states, which provides preverbal infants with a tool for acquiring information beyond their immediate experience.

Do 6-month-olds understand that speech can communicate?

Adults and 12-month-old infants recognize that even unfamiliar speech can communicate information between third parties, suggesting that they can separate the communicative function of speech from its lexical content. But do infants recognize that speech can communicate due to their experience understanding and producing language, or do they appreciate that speech is communicative earlier, with little such experience? We examined whether 6-month-olds recognize that speech can communicate information about an object. Infants watched a Communicator selectively grasp one of two objects (target). During test, the Communicator could no longer reach the objects; she turned to a Recipient and produced speech (a nonsense word) or non-speech (coughing). Infants looked longer when the Recipient selected the non-target than the target object when the Communicator spoke but not when she coughed - unless the Recipient had previously witnessed the Communicators selective grasping of the target object. Our results suggest that at 6 months, with a receptive vocabulary of no more than a handful of commonly used words, infants possess some abstract understanding of the communicative function of speech. This understanding may provide an early mechanism for language and knowledge acquisition.

Prototypicality in sentence production

Three cued-recall experiments examined the effect of category typicality on the ordering of words in sentence production. Past research has found that typical items tend to be mentioned before atypical items in a phrase--a pattern usually associated with lexical variables (like word frequency), and yet typicality is a conceptual variable. Experiment 1 revealed that an appropriate conceptual framework was necessary to yield the typicality effect. Experiment 2 tested ad hoc categories that do not have prior representations in long-term memory and yielded no typicality effect. Experiment 3 used carefully matched sentences in which two category members appeared in the same or in different phrases. Typicality affected word order only when the two words appeared in the same phrase. These results are consistent with an account in which typicality has its origin in conceptual structure, which leads to differences in lexical accessibility in appropriate contexts.

A vowel is a vowel: Generalizing newly-learned phonotactic constraints to new contexts

Adults can learn novel phonotactic constraints from brief listening experience. We investigated the representations underlying phonotactic learning by testing generalization to syllables containing new vowels. Adults heard consonant-vowel-consonant study syllables in which particular consonants were artificially restricted to the onset or coda position (e.g., /f/ is an onset, /s/ is a coda). Subjects were quicker to repeat novel constraint-following (legal) than constraint-violating (illegal) test syllables whether they contained a vowel used in the study syllables (training vowel) or a new (transfer) vowel. This effect emerged regardless of the acoustic similarity between training and transfer vowels. Listeners thus learned and generalized phonotactic constraints that can be characterized as simple first-order constraints on consonant position. Rapid generalization independent of vowel context provides evidence that vowels and consonants are represented independently by processes underlying phonotactic learning.

Representations for Phonotactic Learning in Infancy

Infants rapidly learn novel phonotactic constraints from brief listening experience. Four experiments explored the nature of the representations underlying this learning. 16.5- and 10.5-month-old infants heard training syllables in which particular consonants were restricted to particular syllable positions (first-order constraints) or to syllable positions depending on the identity of the adjacent vowel (second-order constraints). Later, in a headturn listening-preference task, infants were presented with new syllables that either followed the experimental constraints or violated them. Infants at both ages learned first- and second-order constraints on consonant position (Experiments 1 and 2) but found second-order constraints more difficult to learn (Experiment 2). Infants also spontaneously generalized first-order constraints to syllables containing a new, transfer vowel; they did so whether the transfer vowel was similar to the familiarization vowels (Experiment 3), or dissimilar from them (Experiment 4). These findings suggest that infants recruit representations of individuated segments during phonological learning. Furthermore, like adults, they represent phonological sequences in a flexible manner that allows them to detect patterns at multiple levels of phonological analysis.