Learning to represent word meaning: What initial training events reveal about children's developing action verb concepts

Very little experimental research has shown how the events from which verbs are learned affect children's representation of meaning. This study addressed these lacunae by systematically exploring how three different initial training contexts affect children's and adults' interpretation of novel action verbs. Brief, videotaped action events were used to teach children and adults novel verbs in 1 of 3 conditions. Subjects were asked whether these verbs generalized to other events differing only in outcome, manner, instrument, or agent. Initial representation of verb meaning was inferred from generalizations. Unlike 10-year-olds and adults, 3-year-olds' interpretations were (a) significantly context specific—preferring instrument and outcome elements of meaning in one context, but manner in another, and (b) consistently, though moderately biased to favor the manner of action. Results clearly demonstrate that both the young word learner and the context in which word learning occurs are equally important determinants of developing action verb concepts.     

Early Verb Learning: How Do Children Learn How to Compare Events?

An important problem verb learners must solve is how to extend verbs. Children could use cross-situational information to guide their extensions; however, comparing events is difficult. In 2 studies, researchers tested whether children benefit from initially seeing a pair of similar events (“progressive alignment”) while learning new verbs and whether this influence changes with age. In Study 1, 2.5- and 3.5-year-old children participated in an interactive task. Children who saw a pair of similar events and then varied events were able to extend verbs at test and differed from a control group; children who saw 2 pairs of varied events did not differ from the control group. In Study 2, events were presented on a monitor. Following the initial pair of events that varied by condition, a Tobii x120 eye tracker recorded 2.5-, 3.5-, and 4.5-year-olds’ fixations to specific elements of events (areas of interest) during the 2nd pair of events, which were the same across conditions. After seeing the pair of events that were highly similar, 2.5-year-olds showed significantly longer fixation durations to agents and to affected objects as compared with the all-varied condition. At test, 3.5-year-olds were able to extend the verb, but only in the progressive alignment condition. These results are important because they show children’s visual attention to relevant elements in dynamic events is influenced by their prior comparison experience, and they show that young children benefit from seeing similar events as they learn to compare events to each other.     

Vacuuming with my mouth?: Children's ability to comprehend novel extensions of familiar verbs

Can 6- and 8-year-olds (and adults) comprehend common instrument verbs when extended to novel situations? Participants heard eight unusual extensions of common verbs and were asked to paraphrase the verbs’ meanings. Half of the verbs used were specified instrument verbs that include the name of the instrument used to perform the action (e.g., a vacuum is used to vacuum); the other half were open instrument verbs (e.g., write) whose function can be performed with a range of objects. Results suggest that children's ability to interpret verb extensions increases with age, that open instrument verb extensions were more difficult to comprehend than specified instrument verb extensions and that performance on verb extension correlates with scores on a standardized test of language acquisition. Verb knowledge continues to develop well beyond the preschool years.     

"Really? She Blicked the Baby?": Two-Year-Olds Learn Combinatorial Facts About Verbs by Listening

ABSTRACT— Children use syntax to guide verb learning. We asked whether the syntactic structure in which a novel verb occurs is meaningful to children even without a concurrent scene from which to infer the verb's semantic content. In two experiments, 2-year-olds observed dialogues in which interlocutors used a new verb in transitive ("Jane blicked the baby!") or intransitive ("Jane blicked!") sentences. The children later heard the verb in isolation ("Find blicking!") while watching a one-participant event and a two-participant event presented side by side. Children who had heard transitive dialogues looked reliably longer at the two-participant event than did those who had heard intransitive dialogues. This effect persisted even when children were tested on a different day, but disappeared when no novel verb accompanied the test events ( Experiment 2 ). Thus, 2-year-olds gather useful combinatorial information about a novel verb simply from hearing it in sentences, and later retrieve that information to guide interpretation of the verb.     

Attention to Explicit and Implicit Contrast in Verb Learning

Contrast information could be useful for verb learning, but few studies have examined children's ability to use this type of information. Contrast may be useful when children are told explicitly that different verbs apply, or when they hear two different verbs in a single context. Three studies examine children's attention to different types of contrast as they learn new verbs. Study 1 shows that 3.5-year-olds can use both implicit contrast (“I'm meeking it. I'm koobing it.”) and explicit contrast (“I'm meeking it. I'm not meeking it.”) when learning a new verb, while a control group's responses did not differ from chance. Study 2 shows that even though children at this age who hear explicit contrast statements differ from a control group, they do not reliably extend a newly learned verb to events with new objects. In Study 3, children in three age groups were given both comparison and contrast information, not in blocks of trials as in past studies, but in a procedure that interleaved both cues. Results show that while 2.5-year-olds were unable to use these cues when asked to compare and contrast, by 3.5 years old, children are beginning to be able to process these cues and use them to influence their verb extensions, and by 4.5 years, children are proficient at integrating multiple cues when learning and extending new verbs. Together these studies examine children's use of contrast in verb learning, a potentially important source of information that has been rarely studied.     

Graded representations in the acquisition of English and German transitive constructions

English and German children aged 2 years 4 months and 4 years heard both novel and familiar verbs in sentences whose form was grammatical, but which mismatched the event they were watching (e.g., ‘The frog is pushing the lion’, when the lion was actually the ‘agent’ or ‘doer’ of the pushing). These verbs were then elicited in new sentences. All children mostly corrected the familiar verb (i.e., they used the agent as the grammatical subject), but there were cross-linguistic differences among the two-year-olds concerning the novel verb. When English 2-year-olds used the novel verb they mostly corrected. However, their most frequent response was to avoid using the novel verb altogether. German 2-year-olds corrected the novel verb significantly more often than their English counterparts, demonstrating more robust verb-general representations of agent- and patient-marking. These findings provide support for a ‘graded representations’ view of development, which proposes that grammatical representations may be simultaneously abstract but ‘weak’.     

Structural limits on verb mapping: the role of abstract structure in 2.5‐year‐olds’ interpretations of novel verbs

Two experiments showed that 2.5‐year‐olds, as well as older children, interpret new verbs in accord with their number of arguments. When interpreting new verbs describing the same motion events, children who heard transitive sentences were more likely than were children who heard intransitive sentences to assume that the verb referred to the actions of the causal agent. The sentences were designed so that only the number of noun‐phrase arguments differed across conditions (e.g. She’s pilking her over there versus She’s pilking over there). These experiments isolate number of noun‐phrase arguments (or number of nouns) as an early constraint on sentence interpretation and verb learning, and provide strong evidence that children as young as 2.5 years of age attend to a sentence’s overall structure in interpreting it.     

Young children can extend motion verbs to point-light displays

In the first study using point-light displays (lights corresponding to the joints of the human body) to examine children's understanding of verbs, 3-year-olds were tested to see if they could perceive familiar actions that corresponded to motion verbs (e.g., walking). Experiment 1 showed that children could extend familiar motion verbs (e.g., walking and dancing) to videotaped point-light actions shown in the intermodal preferential looking paradigm. Children watched the action that matched the requested verb significantly more than they watched the action that did not match the verb. In Experiment 2, the findings of Experiment 1 were validated by having children spontaneously produce verbs for these actions. The use of point-light displays may illuminate the factors that contribute to verb learning.     

Word learning does not end at fast-mapping: evolution of verb meanings through reorganization of an entire semantic domain

This paper explores the process through which children sort out the relations among verbs belonging to the same semantic domain. Using a set of Chinese verbs denoting a range of action events that are labeled by carrying or holding in English as a test case, we looked at how Chinese-speaking 3-, 5-, and 7-year-olds and adults apply 13 different verbs to a range of carrying/holding events. We asked how children learning Chinese originally divide and label the semantic space in this domain, how they discover the boundaries between different words, and how the meanings of verbs in the domain as a whole evolve toward the representations of adults. We also addressed the question of what factors make verb meaning acquisition easy or hard. Results showed that the pattern of children’s verb use is largely different from that of adults and that it takes a long time for children to be able to use all verbs in this domain in the way adults do. We also found that children start to use broad-covering and frequent verbs the earliest, but use of these verbs tends to converge on adult use more slowly because children could not use these verbs as adults did until they had identified boundaries between these verbs and other near-synonyms with more specific meanings. This research highlights the importance of systematic investigation of words that belong to the same domain as a whole, examining how word meanings in a domain develop as parts of a connected system, instead of examining each word on its own: learning the meaning of a verb invites restructuring of the meanings of related, neighboring verbs.     

Sound symbolism facilitates early verb learning

Some words are sound-symbolic in that they involve a non-arbitrary relationship between sound and meaning. Here, we report that 25-month-old children are sensitive to cross-linguistically valid sound-symbolic matches in the domain of action and that this sound symbolism facilitates verb learning in young children. We constructed a set of novel sound-symbolic verbs whose sounds were judged to match certain actions better than others, as confirmed by adult Japanese- as well as English speakers, and by 2- and 3-year-old Japanese-speaking children. These sound-symbolic verbs, together with other novel non-sound-symbolic verbs, were used in a verb learning task with 3-year-old Japanese children. In line with the previous literature, 3-year-olds could not generalize the meaning of novel non-sound-symbolic verbs on the basis of the sameness of action. However, 3-year-olds could correctly generalize the meaning of novel sound-symbolic verbs. These results suggest that iconic scaffolding by means of sound symbolism plays an important role in early verb learning.     

What preschool children do and do not do with ungrammatical word orders

Akhtar [J. Child Lang. 26 (1999) 339.] found that when 4-year-old English-speaking children hear novel verbs in transitive utterances with ungrammatical word orders (e.g., Elmo the tree meeked), they correct them to canonical SVO order almost all of the time. However, when 3-year-olds and older 2-year-olds hear these same utterances, they waver between correcting and using the ungrammatical ordering. In the current study, we adapted this task for children at 2;4, using an intransitive construction. The major finding was that children corrected the noncanonical word order less than half as often as Akhtar's 2-year-old subjects who were approximately 4 months older. At the same time, however, children showed in several ways that they had some implicit understanding of canonical SV order; for example, they used the novel verb which they heard used in grammatical word order more often than the novel verb which they heard in ungrammatical word order, and they consistently used pronouns and the progressive –s auxiliary in appropriate ways. The current findings thus contribute to a growing body of theory and research suggesting that the ontogenetic emergence of linguistic categories and schemas is a gradual process, as is the emergence of categories in other domains of cognitive development.     

Focusing on the relation: fewer exemplars facilitate children's initial verb learning and extension

One of the most prominent theories for why children struggle to learn verbs is that verb learning requires the abstraction of relations between an object and its action (Gentner, 2003). Two hypotheses suggest how children extract relations to extend a novel verb: (1) seeing many different exemplars allows children to detect the invariant relation between actions in different contexts (Gentner, 2003), and (2) repetition of fewer exemplars allows children to move beyond the entities involved to extract the relation (Kersten & Smith, 2002). We tested 2 1/2- and 3-year-olds' ability to extend a novel verb after viewing the repetition of one novel actor compared to four different actors performing a novel action. Both ages were better at learning and extending a novel verb to a novel actor when shown only one actor rather than four different actors. These results indicate that during initial verb learning less information is more effective.     

Familiar Verbs Are Not Always Easier Than Novel Verbs: How German Pre‐School Children Comprehend Active and Passive Sentences

Many studies show a developmental advantage for transitive sentences with familiar verbs over those with novel verbs. It might be that once familiar verbs become entrenched in particular constructions, they would be more difficult to understand (than would novel verbs) in non‐prototypical constructions. We provide support for this hypothesis investigating German children using a forced‐choice pointing paradigm with reversed agent‐patient roles. We tested active transitive verbs in study 1. The 2‐year olds were better with familiar than novel verbs, while the 2½‐year olds pointed correctly for both. In study 2, we tested passives: 2½‐year olds were significantly below chance for familiar verbs and at chance for novel verbs, supporting the hypothesis that the entrenchment of the familiar verbs in the active transitive voice was interfering with interpreting them in the passive voice construction. The 3½‐year olds were also at chance for novel verbs but above chance with familiar verbs. We interpret this as reflecting a lessening of the verb‐in‐construction entrenchment as the child develops knowledge that particular verbs can occur in a range of constructions. The 4½‐year olds were above chance for both familiar and novel verbs. We discuss our findings in terms of the relative entrenchment of lexical and syntactic information and to interference between them.     

The role of frequency in the acquisition of English word order

Akhtar [Akhtar, N. (1999). Acquiring basic word order: Evidence for data-driven learning of syntactic structure. Journal of Child Language, 26, 339–356] taught children novel verbs in ungrammatical word orders. Her results suggested that the acquisition of canonical word order is a gradual, data-driven process. The current study adapted this methodology, using English verbs of different frequencies, to test whether children's use of word order as a grammatical marker depends upon the frequency of the lexical items being ordered. Ninety-six children in two age groups (2;9 and 3;9) heard either high frequency, medium frequency or low frequency verbs that were modeled in SOV order. Children aged 2;9 who heard low frequency verbs were significantly more likely to adopt the weird word order than those who heard higher frequency verbs. Children aged 3;9 preferred to use SVO order regardless of verb frequency. Furthermore, the younger children reverted to English word order using more arguments as verb frequency increased and used more pronouns than their older counterparts. This suggests that the ability to use English word order develops from lexically specific schemas formed around frequent, distributionally regular items (e.g. verbs, pronouns) into more abstract, productive schemas as experience of the language is accrued.     

Self-referring terms,event transitivity and development of self

We explored 2-year-olds’ developing self-conceptions by examining uses of terms for the self (I, me, own name) to mark contexts of self-action that varied in transitivity. Children differed in their preferred terms for self-reference (I versus proper name/me). “I-users” produced relatively more verbs for highly transitive events that encode subjective experiences of intention and agency and “Name-users” produced relatively more verbs for intransitive events that encode objective experiences of self in motion, even though verb and self-reference vocabularies were similar for the two groups. Results are discussed in terms of children's creative use of language to construct different developmental paths toward self-conceptions and acquisition of the personal pronoun system.     

Meaning from syntax: Evidence from 2-year-olds

When toddlers view an event while hearing a novel verb, the verb’s syntactic context has been shown to help them identify its meaning. The current work takes this finding one step further to reveal that even in the absence of an accompanying event, syntactic information supports toddlers’ identification of verb meaning. Two-year-olds were first introduced to dialogues incorporating novel verbs either in transitive or intransitive sentences, but in the absence of any relevant referent scenes (see Yuan & Fisher, 2009). Next, toddlers viewed two candidate scenes: (a) two participants performing synchronous actions, (b) two participants performing a causative action. When asked to “find mooping”, toddlers who had heard transitive sentences chose the causative scene; those who had heard intransitive sentences did not. These results demonstrate that 2-year-olds infer important components of meaning from syntactic structure alone, using it to direct their subsequent search for a referent in a visual scene.     

2.5-year-olds use cross-situational consistency to learn verbs under referential uncertainty

Recent evidence shows that children can use cross-situational statistics to learn new object labels under referential ambiguity (e.g., Smith & Yu, 2008). Such evidence has been interpreted as support for proposals that statistical information about word-referent co-occurrence plays a powerful role in word learning. But object labels represent only a fraction of the vocabulary children acquire, and arguably represent the simplest case of word learning based on observations of world scenes. Here we extended the study of cross-situational word learning to a new segment of the vocabulary, action verbs, to permit a stronger test of the role of statistical information in word learning. In two experiments, on each trial 2.5-year-olds encountered two novel intransitive (e.g., "She's pimming!"; Experiment 1) or transitive verbs (e.g., "She's pimming her toy!"; Experiment 2) while viewing two action events. The consistency with which each verb accompanied each action provided the only source of information about the intended referent of each verb. The 2.5-year-olds used cross-situational consistency in verb learning, but also showed significant limits on their ability to do so as the sentences and scenes became slightly more complex. These findings help to define the role of cross-situational observation in word learning.     

Verbs and Syntactic Frames in Children’s Elicited Actions: A Comparison of Tamil- and English-Speaking Children

We directly compare children learning argument expressing and argument dropping languages on the use of verb meaning and syntactic cues, by examining enactments of transitive and intransitive verbs given in transitive and intransitive syntactic frames. Our results show similarities in the children’s knowledge: (1) Children were somewhat less likely to perform an action when the core meaning of a verb was in conflict with the frame in which it was presented; (2) Children enacted the core meaning of the verb with considerable accuracy in all conditions; and (3) Children altered their actions to include or not include explicit objects appropriately to the frame. The results suggest that 3-year-olds learning languages that present them with very different structural cues still show similar knowledge about and sensitivity to the core meanings of transitive and intransitive verbs as well as the implications of the frames in which they appear.     

Mental verb input for promoting children's theory of mind: A training study

An experimental study investigated the effect of the type of mental verb input (i.e., input with think, know, and remember) on preschoolers’ theory of mind development. Preschoolers (n = 72) heard 128 mental verb utterances presented in video format across four sessions over two weeks. The training conditions differed only in the way the mental verbs were presented: the form (statement or question), the referent (first person or other person), and the interaction style (overheard or interactive). Children who overheard the characters discussing the mental states of someone else, either in statement or question form, significantly improved in their false belief understanding. These experimental findings demonstrate mental verb utterances about other people, even when not directed to the child, scaffold children's attention to differing perspectives, thus more efficiently promoting some aspects of their ToM development.     

The role of entrenchment in children’s and adults’ performance on grammaticality judgment tasks

Between the ages of 3 and 7 years, children have been observed to produce verb argument structure overgeneralization errors (e.g., Don’t giggle me; Bowerman, 1982, 1988; Pinker, 1989). A number of recent studies have begun to find evidence that the precise distributional properties of the input may provide an important part of the explanation for why children retreat from overgeneralization errors (Brooks & Tomasello, 1999; Brooks, Tomasello, Dodson, & Lewis, 1999). The current study evaluates the role of entrenchment (Braine & Brooks, 1995) in constraining argument structure overgeneralization errors using a grammaticality judgment task. The 5-year-olds, 8-year-olds, and adults were presented with examples of argument structure errors containing high and low frequency verbs matched for semantic class and asked to indicate whether, or the extent to which they found the sentences to be grammatical. The data show that across all groups, sentences with argument structure errors containing low frequency verbs were judged to be significantly more grammatical than those containing high frequency verbs. These findings provide further support for the entrenchment hypothesis and suggest that verb frequency plays an important and continuing role in determining a speaker’s choice of verb argument structure.