1.2 Productive efficiency

Comprehension studies seem to be particularly susceptible to problems of parsing, planning and so forth which impede the full exploitation of linguistic knowledge. Production tasks appear to be less hampered by these extra-grammatical factors. This is probably because production avoids non-verbal response planning, which we have seen is a major source of difficulty in act-out comprehension tasks (Katherine Messenger et al., 2012). Variations in the input can be due to extralinguistic knowledge, such as heuristic-based computations, plausibility of the event or linear thematic assignment (NP1 = Agent). Variations in the output can be due to production pressure. It is possible that in natural languages not all linguistic knowledge is automatically used to facilitate the task of comprehension or production. In the context of production there are a number of possibilities for arriving at a comprehensible output. Jakubowicz’s study (2003) argues that comprehension and production are closely linked in language development, although this relationship does not exclude some qualitative differences between the two modalities. As we will see, correct comprehension can coexist with various strategies in production that reflect the maturation of processes involving several syntactic variables. The aim of the present study was to inform literatures on syntactic development by testing priming effects across development.

1.2.1 Structural priming paradigm

Existing work on the acquisition of syntax has been concerned mainly with the syntax development in children. Structural priming paradigms have shaped theories of syntactic development. In structural priming studies, participants are presented with a prime sentence and then asked to produce a target sentence. Participants who are primed show a significant tendency to reuse the structure of the sentence they have just heard, even when prime and target share no lexical items (Bock, 1986). In other words, people tend to repeat the basic structure of a sentence that they have either just heard (Bock, Dell, Chang, & Onishi, 2007) or just produced (Bock, 1986). This effect is unintentional, and has been demonstrated in speech production (Bock, 1986), written language production (Branigan, Pickering, & Cleland, 1999) and in dialog (Branigan, Pickering, & Cleland, 2000). This structural priming effect cannot be attributed solely to overlap in open or closed class words (Pickering & Branigan, 1998), to prosodic or semantic similarities between prime and target (Bock & Loebell, 1990; Bock, Loebell, & Morey, 1992), or to the repetition of information structure (Hartsuiker & Westenberg, 2000). Unlike adult studies, priming studies with children have not focused on the origin of the priming effect but on what priming can tell us about children’s syntactic representations. In particular, studies have attempted to establish the age at which children show structural priming effects, in order to test the predictions of lexicalist and early abstraction accounts of acquisition.

Recent discussions in the literature on the acquisition of syntax have centered on a debate regarding the nature of children’s early syntactic representations (Fisher, 2002; Naigles, 2002; Tomasello, 2000; Tomasello & Akhtar, 2003). Previous studies in children have shown that prior comprehension influences subsequent production (e.g., Allopenna et al., 1998; Huttenlocher et al., 2004). This suggests that there are structural representations or processes that are common across comprehension and production. However, some have suggested that these representations are employed differently during comprehension and production (Arai et al., 2005). Specifically, it has been proposed that comprehension (unlike production) may be guided exclusively by lexically-specific syntactic information. But results show that children also use abstract syntactic information during the comprehension of datives, which indicate that young children employ abstract structural representations during online sentence comprehension. On one side of this debate are those who believe that early syntactic representations are abstract. This idea, the Generalization Hypothesis, rests on the claim that even very young children have formed generalizations about the syntax of their native languages that are not simply rote-learned formulae tied to specific lexical items. Support for the Generalization Hypothesis comes from studies of early language comprehension. On the other side of the debate are those who suggest that young children’s syntax develops in a piecemeal way. This Item-Based Hypothesis postulates that early syntax is based on knowledge of the argument structures of inpidual lexical items and that these item-specific representations persist into the fourth year of life. Much of the work in support of the Item-Based Hypothesis comes from research examining children’s productive language abilities (Erin Conwell & Katherine Demuth, 2005). The precise nature of the earliest representations varies from theory to theory, but, crucially, children’s knowledge of syntactic relations does not go through a lexically-dependent stage of development. In order to distinguish between lexicalist and early abstraction accounts, researchers have focused on establishing whether young children pass through a stage in which they only show priming when prime and target share lexical items (e.g. verbs or pronouns) before developing the abstract categories required for lexically independent (abstract) priming (Bencini & Valian, 2008; Huttenlocher, Vasilyeva, & Shimpi, 2004; Messenger, Branigan, & McLean, 2011; Messenger, Branigan, McLean, & Sorace, 2012; Savage, Lieven, Theakston, & Tomasello, 2003; Shimpi, Gamez, Huttenlocher, & Vasilyeva, 2007; Thothathiri & Snedeker, 2008).