RUNNING HEAD: The development of verb argument structure
When do children develop knowledge of verb argument structure? Evidence from verb bias effects in a structural priming task
Michelle Peter1a
Caroline F. Rowland1
Franklin Chang1
University of Liverpool
Ryan Blything2
University of Manchester
1Department of Psychological Sciences, Institute of Psychology, Health & Society, University of Liverpool, Eleanor Rathbone Building, Liverpool, L69 7ZA, UK.
2Max Plank Child Study Centre, School of Psychological Sciences, University of Manchester, Manchester, M13 9PL, UK.
a Corresponding author: Michelle Peter, Department of Psychological Sciences, Institute of Psychology, Health & Society, University of Liverpool, Eleanor Rathbone Building, Liverpool, L69 7ZA, UK. Email: . Telephone: +44 151 7941401.
Abstract
The structural priming paradigm is a powerful way of constraining theories about how children’s knowledge of verb-argument structure develops. Using a priming task that capitalises on verb bias effects and on a phenomenon called prime surprisal, we tested two accounts of syntactic development: one by ThothathiriSnedeker [Thothathiri, M. & Snedeker, J. (2008a). Syntactic priming during language comprehension in three- and four-year-old children.Journal of Memory and Language, 58, 188-213]that claims that children have abstract knowledge about syntax before they learn the lexical links to these structures from verbs, and another by Chang, Dell, and Bock [Chang, F., Dell, G. S., & Bock, K. (2006). Becoming syntactic.Psychological Review, 113, 234-272] that proposes that children acquire abstract and lexical knowledge simultaneously. We assessed structural priming and the lexical boost across development. We also investigated whether the bias of the target verb influences structural priming across development, and whether the priming effect is stronger when there is a mismatch between prime verb bias and prime structure (prime surprisal).Children (aged 3-4 years and 5-6 years old) and adults heard and produced double-object dative (DOD) and prepositional-object dative (PD) primes with DOD- and PD-biased verbs. All participants heard both the same verb in the prime and target (e.g., gave-gave), and also a different verb (e.g., gave-sent). All age groups demonstrated significant evidence of structural priming, but only adults showed increased priming when the prime and target shared a verb (the lexical boost). Both children and adults produced more DOD responses with DOD-biased verbs (e.g., give) than with PD-biased verbs (e.g., bring), and priming was stronger when there was a mismatch between the prime verb’s bias and its structure (prime surprisal). These results show that, like adults, children’s knowledge of verb syntactic preferences influences their structure choice. We conclude that early syntax is lexically-grounded and that the lexical boost is not a reliable measure of verb-structure links.
Keywords: structural priming, syntactic development, verb bias, lexical boost, prime surprisal.
When do children develop knowledge of verb argument structure? Evidence from verb bias effects in a structural priming task
Structural priming is a powerful way of measuring what adults know about syntactic structure. A number of priming studies have shown that, despite having the ability to be linguistically creative, adult speakers tend to repeat the syntactic structure of the sentences that they have recently encountered (Bock, 1986b). This effect is not contingent on non-syntactic factors such as the prosody of sentences or the thematic roles played by arguments, nor does it rely on the repetition of words across sentences - although the priming effect is often larger when prime and target sentences share a verb (the lexical boost; Pickering & Branigan, 1998). Thus, the phenomenon of structural priming is widely interpreted as evidence that adults have abstract representations of syntax that are stored independently of lexical items (e.g., Bock & Loebell, 1990; Cleland & Pickering, 2006; Noppeney& Price, 2004).
Recently, the priming paradigm has helped us to learn more about children’s syntactic representations. These studies have been particularly useful in informing us about the way in which children’s knowledge of syntactic structure is similar to (and differs from) that of adults. For example, Shimpi, Gámez, Huttenlocher, and Vasilyeva (2007) found that children as young as three years old, who heard and repeated passive prime sentences, were more likely to describe target pictures using a passive rather than an active structure. Similar results were reported in a more recent study by Messenger, Branigan, McLean, and Sorace (2012). Evidence of abstract structural priming in children has also been demonstrated in language comprehension; Thothathiri and Snedeker (2008a) reported that children’s interpretation of target dative sentences was influenced by prior processing of dative prime sentences that contained a different verb. The fact that these finding hold even when prime and target do not share any lexical items, suggests that, like adults, children as young as three years old possess verb-general abstract syntactic representations that they employ during both production and comprehension. Thus, the results from the child literature are fairly consistent: children appear to have abstract knowledge of syntax from early on in development.
However, priming studies in the acquisition literature tend to focus only on this question of what type of syntactic knowledge children have at the early stages of the acquisition process. While this approach is a useful way of distinguishing between early abstraction and item-specific theories (e.g., Fisher, 2002a; Pinker 1984; Valian, 1986 vs. Pine, Lieven & Rowland, 1998; Tomasello, 1992; 2000), it does not tell us much about how children’s knowledge of syntactic structure develops. Given that children cannot start with an adultlike knowledge of the particular syntactic structures used in their language, all theories need to incorporate acquisition mechanisms that enable children to interpret their own particular input to build knowledge of syntax. Studying how children’s responses to priming tasks change over development allows us to examine not only what knowledge children bring to the language learning task, but also how acquisition mechanisms interact with the input to build mature linguistic knowledge.
Recently, Rowland, Chang, Ambridge, Pine, and Lieven (2012) used a structural priming task to investigate just this. Using a paradigm designed to test structural priming across development, they reported significant structural priming effects in both children (aged 3-4 years and 5-6 years) and adults. All age group produced more double-object dative (DOD) responses after a DOD prime than after a prepositional-object dative (PD) prime even when the prime and the target included different verbs (e.g., give-send). From the fact that there were no significant differences across development, the authors concluded that three year olds, like older children and adults, have already built abstract syntactic representations of English dative constructions.
However, when prime and target sentences shared a verb, the pattern of priming differed across development; unlike adults, children did not show a lexical boost effect. The adults demonstrated a substantially larger priming effect when there was verb overlap compared to when the prime and target verbs were different (a significant lexical boost of 34%). However, the effect was only marginal in the 5-6 year olds (10%) and non-existent in the 3-4 year olds. In other words, the repetition of verbs across sentences did not act to enhance the priming effect for the youngest age group in the same way that it did for adults.
These results have implications for our understanding about the relationship between abstract and lexical knowledge across development.One possible explanation is that the lexical boost isabsent in the youngest children because adults and children differ in the way in which they have linked the verb lexicon to knowledge of syntactic structure. For the adults in Rowland et al.’s (2012) study, the presence of the lexical boost suggests that syntactic structure choice is influenced, not only by the activation of the prime structure, but by activation of the verb used in the prime. This occurs because, in adult representations, there are connections between verbs and syntactic structure in the form of argument structure links that specify the syntactic structures in which verbs can occur (see Pickering & Branigan, 1998). However, in three-year olds, these verb-structure links may not exist, or, at least, may not be strong enough yet to influence syntactic choices in a priming paradigm. Thothathiri and Snedeker (2008a) have suggested that children may first build abstract representations of syntactic structures (e.g., the dative structure), and only later establish links between these representations and individual verbs, building knowledge of the argument structure constraints of verbs slowly as experience with each individual verb accumulates. On this view, children’s syntactic representations are initially wholly abstract, and the lack of a lexical boost in the youngest age group is due to an absence of any links between verbs and structures.
An alternative explanation, however, is that the lexical boost is the wrong tool to make inferences about the relationship between verbs and syntactic structure. On this model, the lexical boost doesnotstem from a lack of knowledge of verb argument structure but from a limitation in explicit memory.. According to Chang, Dell, and Bock (2006), structural priming occurs as a consequence of an error-based learning mechanism. In their Dual-path model, which provides an account of structural priming,the difference (or error) between predicted and actual sentences is used to makes gradual weight changes in the connections between syntactic representations. Because the model conceptualizes structural priming in terms of the same learning mechanism that drives syntax acquisition, theseweight changes enable the model to learn syntactic structure whilstdeveloping representations based on the structural properties of verbs. In this way, Chang et al. predict that verb-structure links develop in parallel with the development of syntactic knowledge. Lexical boost effects, however, are too large to result from these types of changes; they result, instead from the speaker’s explicit awareness of the repetition of lexical items across prime and target sentences (Chang, Janciauskas, & Fitz, 2012). On this model, lexical overlap simply acts as a cue in the retrieval of the explicit memory of the prime structure and, given that explicit memory increases with age (Naito, 1990; Sprondel, Kipp, & Mecklinger, 2011), the boost increases in line with the ability to form, store, and retrieve explicit memories. Thus, the lexical boost is small (or even absent) in young children not because children do not have verb-structure links, but because they are less efficient at retrieving an explicit memory trace of the prime sentence.
In sum, there are two possible reasons for why children and adults respond differently in lexical boost paradigms; one that suggests that children’s knowledge of verb-structure links has yet to develop, and one that suggest that it develops in parallel with knowledge of syntactic structure, but that the lexical boost is the wrong place to look for these links in children. In order to distinguish between these two theories, and determine what children know about verb argument structure, we thus need to use a different method to establish whether children’s and adults’ knowledge of verb argument structure influences their syntactic structure choice. In the current study, we did this using a modified structural priming method; one that capitalises on verb bias effects in priming studies and on a phenomenon called prime surprisal.
Verb bias and prime surprisal
Although many dative verbs can occur in both prepositional and double object datives (e.g.,I gave him a cake/I gave a cake to him), most of these verbs will tend to occur more often in one structure than another. For example, give tends to occur more often in double object than prepositional dative structures (Campbell & Tomasello, 2001; GriesStefanowitsch , 2004a). These syntactic preferences (or preferred argument structure constraints) affect how adults behave in priming studies. For example, in a corpus analysis of English dative verbs, Gries (2005) found that target verbs strongly associated with one structure resisted being primed into another structure. In another study by Coyle and Kaschak (2008), priming effects were found to be larger when the target verb was not strongly associated with one structure (i.e., when they were equi-biased). In other words, an adult’s knowledge of a verb’s preferred argument structure (i.e., whether this verb occurs more often in a DOD or a PD structure) influences how easily it is to prime that adult to produce the verb in that structure.
Studying the effect of verb bias on priming provides us with a different way of tapping into a participant’s knowledge of the links between verbs in the lexicon and syntactic structure. We know that adults’ knowledge of a verb’s preferred argument structure influences their structure choice during a priming task. If children have also established these links (as predicted by Chang et al, 2006), then we should expect to see evidence of target verb bias effects across development. However, if children have not yet linked verbs with their argument structure preferences (as predicted by Thothathiri and Snedeker, 2008a), then only adults, and perhaps older children, should demonstrate target verb bias effects during a structural priming task.
In addition, related research has suggested that the identity of the prime verb plays an important role in the size of the priming effect, such that priming is stronger when the bias of the prime verb makes its occurrence in a particular prime structure unexpected – an effect termed prime surprisal (Chang et al., 2006). For example, Jaeger and Snider (2007) found that adults were more strongly primed when DOD-biased prime verbs were presented in a PD prime structure andBernolet and Hartsuiker (2010) reportedstronger priming when primes with PD-biased verbs were presented in a DOD-structure in Dutch. In other words, the more unexpected (or surprising) a verb is in a prime sentence, the more likely participants are to be primed.
Not only do these results demonstrate that adult speakers store information about verb syntactic preferences, but they also suggest that adults make predictions about prime sentences based on their knowledge of these preferences. When these predictions are not met (i.e., when a verb is presented in an unexpected structure), prime surprisal works to boost the priming effect (Chang et al., 2006).We can exploit this to assess children’s knowledge of verb-structure links. If, like adults, children have created links between verbs and syntactic structure, then verb-structure mismatches during a structural priming task should also lead to prime surprisal effects in children. But, if they have not yet formed these verb-structure links, then we should only expect to see evidence of prime surprisal effects in adults.
The current study
In this study, we capitalise on verb bias and prime surprisal effects to test two accounts of how children develop knowledge of verb argument structure. One possibility is that children have abstract knowledge about syntax before they learn verb argument structure links between syntactic structures and individual verbs (ThothathiriSnedeker, 2008a). Onthis view, we should see abstract structural priming across development but, because children have not yet created the links between verbs and the structures in which these verbs can occur, only adults should demonstrate evidence of lexical boost, target verb bias effects and prime surprisal. Another possibility is that children acquire abstract and lexical knowledge simultaneously, but that the lexical boost is not a reliable measure of verb-structure links (Chang et al., 2006). This account also predicts abstract structural priming across development and a lexical boost that increases with age. However, on this account, we should see target verb bias effects and prime surprisal across development since this account predicts that children acquire both abstract syntactic representations and knowledge of verb argument structure simultaneously from early on.
The current study used a modified version of the priming paradigm used by Rowland et al. to test for structural and verb-specific priming effects in young children (3-4 years), older children (5-6 years), and adults. Children and adults heard and repeated DOD and PD prime sentences containing DOD- (give and show) and PD-biased verbs (bring and send) before producing target sentences with these verbs. First, we assessed whether we could replicate the findings of Rowland et al. by examining structural priming and the lexical boost across development. To do this, we observed whether participants produced more DOD- target sentences after DOD primes than after PD primes when verbs in the prime in the target were different (e.g., give-send), and then observed whether this priming effect increased when the prime and target verb were the same (e.g., give-give). Second, we tested whether children, like adults, show verb bias effects in priming tasks by exploring whether the size of the priming effect was influenced by the bias of the target verb. Third, we assessed whether children, like adults, demonstrate evidence of prime surprisal. To do this we explored the priming effect was stronger when prime verb bias and prime syntactic structure were mismatched (e.g., DOD-biased verb in a PD structure).