Pierce, Genesee, Delcenserie, and Morgan (2017) are right to suggest that working memory is a crucial part of the machinery underlying linguistic development. In this brief commentary, I will move beyond the emergence of phonological representations, on which Pierce et al.’s essay focuses, and consider ways in which working memory shapes the character and acquisition of grammatical phenomena, a topic that has been explored in various ways in the recent literature (e.g., Chater & Christiansen, 2010; Hawkins, 2014; O'Grady, 2005, 2015).

Priming reflects the reactivation of processing routines that map strings of words onto semantic representations (and vice versa) without the mediation of syntactic structure, including the “flat structure” that Branigan & Pickering (B&P) propose. Key evidence for this claim comes from the possibility of priming relations involving subject-verb sequences, which are not syntactic constituents.

This paper investigates English-speaking children's acquisition of raising constructions (e.g. John seems to Mary to be happy) and finds an asymmetric effect of NP type on their comprehension: an improvement in performance is observed when a lexical NP is raised across a pronominal experiencer (e.g. John seems to her to be happy) compared to when a pronoun is raised across a lexical NP experiencer (e.g. He seems to Mary to be happy). These results are consistent with a processing-based approach to intervention effects, which reduces children's difficulty with raising to a performance limitation, rather than a grammatical deficit.

I focus on two challenges that processing-based theories of language must confront: the need to explain why language has the particular properties that it does, and the need to explain why processing pressures are manifested in the particular way that they are. I discuss these matters with reference to two illustrative phenomena: proximity effects in word order and a constraint on contraction.

We report here on a series of elicited production experiments that investigate the production of indirect object and oblique relative clauses by monolingual child learners of English and Korean. Taken together, the results from the two languages point toward a pair of robust asymmetries: children manifest a preference for subject relative clauses over indirect object relative clauses, and for direct object relative clauses over oblique relative clauses. We consider various possible explanations for these preferences, of which the most promising seems to involve the requirement that the referent of the head noun be easily construed as what the relative clause is about.

Most explanatory work on first and second language learning assumes the primacy of the acquisition phenomenon itself, and a good deal of work has been devoted to the search for an ‘acquisition device’ that is specific to humans, and perhaps even to language. I will consider the possibility that this strategy is misguided and that language acquisition is a secondary effect of processing amelioration: attempts by the processor to facilitate its own functioning by developing routines of particular sorts.

It is widely recognized that the processor has a key role to play in creating and strengthening the mapping between form and meaning that is integral to language use. Adopting an emergentist approach to heritage language acquisition, the current study considers the extent to which the operation of the processor can contribute to an account of what is acquired, what is subsequently retained or lost, and what is never acquired in the first place. These questions are explored from two perspectives. First, morphosyntactic phenomena for which there is apparently substantial input are considered, with a focus on the relevance of salience, frequency, and transparency to the establishment of form-meaning mappings. Second, a phenomenon for which there appears to be relatively little input (i.e., scope) is examined with a view to understanding its fate in heritage language acquisition. In both cases, the emergentist perspective appears to offer promising insights into why heritage language learners succeed—and fail—in the way that they do.