Developmental consistency in the use of subphonemic information during real-time sentence processing.

Apparently homophonous sequences contain acoustic information that differentiates their meanings (Gahl, 2008; Quené, 1992). Adults use this information to segment embedded homophones (e.g., ham vs. hamster; Salverda, et al., 2003) in fluent speech. Whether children also do this is unknown, as is whether listeners of any age use such information to disambiguate lexical homophones. In two experiments, 48 English-speaking adults and 48 English-speaking 7- to- 10-year-old children viewed sets of four images and heard sentences containing phonemically identical sequences while their eye movements were continuously tracked. As in previous research, adults showed greater fixation of target meanings when the acoustic properties of an embedded homophone were consistent with the target than when they were consistent with the alternate interpretation. They did not show this difference for lexical homophones. Children's behavior was similar to that of adults, indicating that the use of subphonemic information in homophone processing is consistent over development.

A pre-registered, multi-lab non-replication of the action-sentence compatibility effect (ACE).

The Action-sentence Compatibility Effect (ACE) is a well-known demonstration of the role of motor activity in the comprehension of language. Participants are asked to make sensibility judgments on sentences by producing movements toward the body or away from the body. The ACE is the finding that movements are faster when the direction of the movement (e.g., toward) matches the direction of the action in the to-be-judged sentence (e.g., Art gave you the pen describes action toward you). We report on a pre-registered, multi-lab replication of one version of the ACE. The results show that none of the 18 labs involved in the study observed a reliable ACE, and that the meta-analytic estimate of the size of the ACE was essentially zero.

Repetition, but not acoustic differentiation, facilitates pseudohomophone learning by children.

Children's ability to learn words with multiple meanings may be hindered by their adherence to a one-to-one form-to-meaning mapping bias. Previous research on children's learning of a novel meaning for a familiar word (sometimes called a pseudohomophone) has yielded mixed results, suggesting a range of factors that may impact when children entertain a new meaning for a familiar word. One such factor is repetition of the new meaning (Storkel & Maekawa, 2005) and another is the acoustic differentiation of the two meanings (Conwell, 2017). This study asked 72 4-year-old English-learning children to assign novel meanings to familiar words and manipulated how many times they heard the words with their new referents as well as whether the productions were acoustically longer than typical productions of the words. Repetition supported the learning of a pseudohomophone, but acoustic differentiation did not.

Argument Types Affect Children's Acquisition of a Novel Argument Structure.

Acquisition of an argument structure may be affected by the diversity of lexical types that appear in that structure (Conwell et al., 2011; Yang, 2016). Seventy-two 5- and 6-year-old English-speaking children completed a learning study where they were exposed to a novel argument structure and then tested on their ability to comprehend it. The number of verb types heard in the learning phase did not predict comprehension at test. However, learning with only full noun phrase arguments resulted in lower comprehension of the structure, particularly with pronouns. Hearing pronouns during learning supported comprehension of all argument types at test. These results indicate that pronominal arguments support argument structure learning by providing multiple cues that can facilitate thematic role assignment.

The effects of the pronoun me on dative comprehension.

The English dative alternation has received much attention in the literature on argument structure acquisition in children. However, the data on the acquisition of this alternation have consistently revealed a counter-intuitive pattern: children look more proficient with the lower frequency prepositional form of the dative than with the higher frequency double object form (Conwell & Demuth, 2007; Rowland & Noble, 2010). This may be because the DO dative typically occurs with pronominal argument types in first post-verbal position, which may result in an over-reliance on stereotyped forms (e.g., give + me) for early comprehension and production (Conwell, O'Donnell, & Snedeker, 2011). This paper presents three studies of the effects of the pronoun me on dative comprehension by three-year-olds. Children's comprehension of the DO dative improved significantly when the first post-verbal argument was pronominal; no other effects of pronoun use were significant. Children's experience affects their ability to use lexically general representations of syntactic structures.

Phrase Position, but not Lexical Status, Affects the Prosody of Noun/Verb Homophones.

Words that can occur in more than one lexical category produce regions of ambiguity that could confound language learning and processing. However, previous findings suggest that pronunciation of noun/verb homophones may, in fact, differ as a function of category of use, potentially mitigating that ambiguity. Whether these differences are part of the lexical representation of such words or mere by-products of sentence-level prosodic processes remains an open question, the answer to which is critical to resolving questions about the structure of the lexicon. In three studies, adult native speakers of English read aloud passages containing noun/verb homophones or nonce words used in both noun and verb contexts. Acoustic measurements of the target words indicated that, while sentence position influences the acoustic properties of noun/verb homophones, including duration and pitch, there are not significant effects of lexical category when other factors are controlled. Furthermore, the lexical status of a word (real or nonce) does not produce consistent prosodic effects. These findings suggest that previously reported prosodic differences in noun/verb homophones may result from the syntactic positions in which those categories tend to occur.

The use of acoustic information in lexical ambiguity resolution: an event-related potential study.

Words that can be used as both noun and verb create regions of syntactic ambiguity that could create processing challenges for listeners. However, acoustic properties, such as duration, differ between noun and verb uses of such words, and listeners may use these differences to facilitate ambiguity processing. In this study, we replaced noun uses of ambiguous words with verb uses to determine whether these manipulations affected the N400 event-related potential, which is associated with semantic violations, or the P600 component, which is associated with syntactic ambiguity. The results suggest that the acoustic differences between noun/verb polysemes mitigate the extent to which these words are perceived as ambiguous, although the results do not indicate whether replacing one with the other produces a meaning violation. Durational differences in noun/verb polysemes may affect their processing in fluent speech.

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.

Are Homophones Acoustically Distinguished in Child-Directed Speech?

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.

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 100ms following stimulus onset and persisting for over 400ms. 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.

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, children's 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 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.

Early syntactic productivity: evidence from dative shift.

The abstractness of children's early syntactic representations has been questioned in the recent acquisition literature. While some research has suggested that children's 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 children's 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 children's 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.

Receptive Grammatical Knowledge of Familiar Content Words and Inflection in 16-Month-Olds.

This study examines 16-month-olds' understanding of word order and inflectional properties of familiar nouns and verbs. Infants preferred grammatical sentences over ungrammatical sentences when the ungrammaticality was cued by both misplaced inflection and word order reversal of nouns and verbs. Infants were also sensitive to inflection alone as a cue to grammaticality, but not word order alone. The preference for grammatical sentence forms was also disrupted when adjacent function word cues were removed from the stimuli, and when familiar content words were replaced by nonce words. These results suggest that sensitivity to the relationship between functional morphemes and content words, rather than sensitivity to either independently, drives the development of early grammatical knowledge. Furthermore, infants showed some ability to generalize from familiar to nonce content word contexts.