Extending previous research that has examined the relationship between long-term memory and second language (L2) development with a primary focus on accuracy in L2 outcomes, the current study explores the relationship between declarative and procedural memory and accuracy and automatization during L2 practice. Adult English native speakers had learned an artificial language over two weeks (Morgan-Short, Faretta-Stutenberg, Brill-Schuetz, Carpenter & Wong, 2014), producing four sessions of practice data that had not been analyzed previously. Mixed-effects models analyses revealed that declarative memory was positively related to accuracy during comprehension practice. No other relationships were evidenced for accuracy. For automatization, measured by the coefficient of variation (Segalowitz, 2010), the model revealed a positive relationship with procedural memory that became stronger over practice for learners with higher declarative memory but weaker for learners with lower declarative memory. These results provide further insight into the role that long-term memory plays during L2 development.

This study examined how individual differences in cognitive abilities account for variance in the attainment level of adult second language (L2) syntactic development. Participants completed assessments of declarative and procedural learning abilities. They subsequently learned an artificial L2 under implicit training conditions and received extended comprehension and production practice using the L2. Syntactic development was assessed at both early and late stages of acquisition. Results indicated positive relationships between declarative learning ability and syntactic development at early stages of acquisition and between procedural learning ability and development at later stages of acquisition. Individual differences in these memory abilities accounted for a large amount of variance at both stages of development. The findings are consistent with theoretical perspectives of L2 that posit different roles for these memory systems at different stages of development, and suggest that declarative and procedural memory learning abilities may predict L2 grammatical development, at least for implicitly trained learners.

It remains unclear whether adult-learned second language (L2) depends on similar or different neurocognitive mechanisms as those involved in first language (L1). We examined whether English past tense forms are computed similarly or differently by L1 and L2 English speakers, and what factors might affect this: regularity (regular vs. irregular verbs), length of L2 exposure (length of residence), age of L2 acquisition (age of arrival), L2 learners’ native language (Chinese vs. Spanish), and sex (male vs. female). Past tense frequency effects were used to examine the type of computation (composition vs. storage/retrieval). The results suggest that irregular past tenses are always stored. Regular past tenses, however, are either composed or stored, as a function of various factors: both sexes store regulars in L2, but only females in L1; greater lengths of residence lead to less dependence on storage, but only in females; higher adult ages of arrival lead to more reliance on storage. The findings suggest that inflected forms can rely on either the same or different mechanisms in L2 as they do in L1, and that this varies as a function of multiple interacting factors.

Obsessive-compulsive disorder (OCD) has been associated with frontostriatal abnormality. This has led to the hypothesis that the disorder is characterized by abnormality of procedural memory. However, evidence for either procedural or declarative memory disturbance has been mixed, and few studies have directly assessed both of these forms of memory in the same patient group. In the present study, we assessed encoding and retrieval in declarative memory using the Rey Auditory Verbal Learning Test (RAVLT), and procedural memory using the Pursuit Rotor Task, in 27 adults with OCD and 29 matched healthy controls. Groups did not differ with respect to salient demographic characteristics or memory on the RAVLT. In contrast, patients with OCD performed significantly better than controls during the early, but not later trial blocks of the Pursuit Rotor Task. This pattern of results indicates intact encoding and retrieval in declarative memory, but abnormally enhanced procedural memory during the early course of learning in OCD. These findings may be consistent with striatal overactivation observed in neuroimaging studies of OCD, as well as the prominent role of the striatum during early stages of procedural memory. (JINS, 2004, 10, 647–654.)