Erin Conwell

Early syntactic productivity: Evidence from dative shift ☆

The abstractness of childrens early syntactic representations has been questioned in the recent acquisition literature. While some research has suggested that childrens knowledge of basic constructions such as the transitive is robust and abstract at a very young age, other work has proposed that young children only have constructions that are specific to individual lexical items. The present paper seeks to resolve this discrepancy by examining childrens abstract knowledge of the English dative alternation via a production study. The studies ask whether young children who hear a sentence like I pilked the cup to Petey know that the same meaning can be expressed with the sentence I pilked Petey the cup. This generalization is well-attested in the language that children hear and represents a strong test-case for determining the nature of childrens early syntactic representations. The results indicate that three-year-old children have productive knowledge of the English dative alternation, but that their performance can be influenced by small changes in the nature of the task. A preference for the prepositional dative form is also found and the possible reasons for this preference are discussed.

The Effect of Real-World Personal Familiarity on the Speed of Face Information Processing

Background Previous studies have explored the effects of familiarity on various kinds of visual face judgments, yet the role of familiarity in face processing is not fully understood. Across different face judgments and stimulus sets, the data is equivocal as to whether or not familiarity impacts recognition processes. Methodology/Principal Findings Here, we examine the effect of real-world personal familiarity in three simple delayed-match-to-sample tasks in which subjects were required to match faces on the basis of orientation (upright v. inverted), gender and identity. We find that subjects had a significant speed advantage with familiar faces in all three tasks, with large effects for the gender and identity matching tasks. Conclusion/Significance Our data indicates that real-world experience with a face exerts a powerful influence on face processing in tasks where identity information is irrelevant, even in tasks that could in principle be solved via low-level cues. These results underscore the importance of experience in shaping visual recognition processes.

Is It a Noun or Is It a Verb? Resolving the Ambicategoricality Problem

In many languages, significant numbers of words are used in more than one grammatical category; English, in particular, has many words that can be used as both nouns and verbs. Such ambicategoricality potentially poses problems for children trying to learn the grammatical properties of words and has been used to argue against the logical possibility of learning grammatical categories from syntactic distribution alone. This article addresses how often English-learning children hear words used across categories, whether young language learners might be sensitive to perceptual cues that differentiate noun and verb uses of such words and how young speakers use ambicategorical words. The findings suggest that children hear considerably less cross-category usage than is possible and are sensitive to perceptual cues that distinguish the two categories. Furthermore, in early language production, childrens cross-category production mirrors the statistics of their linguistic environments, suggesting that they are distinguishing noun and verb uses of individual words in natural language exposure. Taken together, these results indicate that cues in the speech stream may help children resolve the ambicategoricality problem.

The learner as statistician: three principles of computational success in language acquisition

© 2009 The Authors. Journal compilation

Prosodic disambiguation of noun/verb homophones in child-directed speech.

One strategy that children might use to sort words into grammatical categories such as noun and verb is distributional bootstrapping, in which local co-occurrence information is used to distinguish between categories. Words that can be used in more than one grammatical category could be problematic for this approach. Using naturalistic corpus data, this study asks whether noun and verb uses of ambiguous words might differ prosodically as a function of their grammatical category in child-directed speech. The results show that noun and verb uses of ambiguous words in sentence-medial positions do differ from one another in terms of duration, vowel duration, pitch change, and vowel quality measures. However, sentence-final tokens are not different as a function of the category in which they were used. The availability of prosodic cues to category in natural child-directed speech could allow learners using a distributional bootstrapping approach to avoid conflating grammatical categories.

Neural responses to category ambiguous words

Category ambiguous words (like hug and swing) have the potential to complicate both learning and processing of language. However, uses of such words may be disambiguated by acoustic differences that depend on the category of use. This article uses an event-related potential (ERP) technique to ask whether adult native speakers of English show neural sensitivity to those differences. The results indicate that noun and verb tokens of ambiguous words produce differences in the amplitude of the ERP response over left anterior sites as early as 100 ms following stimulus onset and persisting for over 400 ms. Nonsense words extracted from noun and verb contexts do not show such differences. These findings suggest that the acoustic differences between noun and verb tokens of ambiguous words are perceived and processed by adults and may be part of the lexical representation of the word.

Are Homophones Acoustically Distinguished in Child-Directed Speech?

ABSTRACT Many approaches to early word learning posit that children assume a one-to-one mapping of form and meaning. However, children’s early vocabularies contain homophones, words that violate that assumption. Children might learn such words by exploiting prosodic differences between homophone meanings that are associated with lemma frequency (Gahl, 2008). Such differences have not yet been documented in children’s natural language experience and the exaggerated prosody of child-directed speech could either mask the subtle distinctions reported in adult-directed speech or enhance them. This study measured the duration, vowel characteristics, and pitch information of homophone tokens taken from a corpus of child-directed speech. The results show that homophone meanings are acoustically distinct in child-directed speech as a function of lemma frequency, particularly in utterance-final positions. Such distinctions may allow children to maintain separate phonetic representations of homophones until their cognitive and linguistic abilities are robust to violations of the one-to-one bias.

Token Frequency Effects in Homophone Production: An Elicitation Study

In natural production, adults differentiate homophones prosodically as a function of the frequency of their intended meaning. This study compares adult and child productions of homophones to determine whether prosodic differentiation of homophones changes over development. Using a picture-based story-completion paradigm, isolated tokens of homophones were elicited from English-learning children and adult native English speakers. These tokens were measured for duration, vowel duration, pitch, pitch range, and vowel quality. Results indicate that less frequent meanings of homophones are longer in duration than their more frequent counterparts in both adults and children. No other measurement differed as a function of meaning frequency. As speakers of all ages produce longer tokens of lower frequency homophones, homophone differentiation does not change over development, but is included in children’s early lexicons. These findings indicate that production planning processes alone may not fully account for differences in homophone duration, but rather that the differences could be learned and represented from experience even in the early stages of lexical acquisition.