A neurocognitive perspective on retrieval interference in L2 sentence processing

Cunnings (Cunnings) offers an interpretation of L2-L1 sentence processing differences in terms of memory principles. We applaud such cross-domain approaches, which seem likely to significantly elucidate the neurocognition of language. Cunnings attributes sentence processing differences between (adult) high proficiency L2 and L1 speakers to an increased susceptibility to similarity-based retrieval interference, rather than to qualitative L2-L1 processing differences (cf. Clahsen & Felser, 2006). On his account, both L1 and L2 sentence processing depend upon a ‘bipartite’ working memory, which involves maintaining items active by focusing attention on longterm memory representations (Cowan, 2001). We first discuss Cunnings’ account from the perspective of a well-studied neurocognitive model that links language to memory, the declarative/procedural model (Ullman, 2015, 2016). We then consider some issues that moderate our confidence in Cunnings’ conclusions. If we assume Cunnings’ account of sentence processing is correct, how might it be interpreted in light of the declarative/procedural model (an interpretation Cunnings’ himself remains agnostic about; section 2)? Similar to Cunnings, the declarative/procedural model claims that, in higher proficiency/exposure L2 speakers, rule-governed grammar can be learned and processed in L1 neurocognitive substrates, specifically procedural memory, though at lower proficiency/exposure grammar relies importantly on declarative memory. In contrast, idiosyncratic (non-derivable) information must always be stored (in both L1 and L2) in declarative memory. Declarative memory is closely linked to working memory, which may provide input/output mechanisms for knowledge stored in this system, including lexical information (Ullman, 2016). Thus, sentence processing in both L1 and high proficiency L2 speakers should rely on procedural memory processes for syntactic parsing, and declarative and working memory for the retrieval of information stored in the lexicon. One of the basic tenets of the declarative/procedural model is that, since language depends on memory