Domain-specific and domain-general constraints on word and sequence learning

Mem Cogn (2013) 41:268–280 DOI 10.3758/s13421-012-0259-4 Domain-specific and domain-general constraints on word and sequence learning Lisa M. D. Archibald & Marc F. Joanisse Published online: 26 September 2012 # Psychonomic Society, Inc. 2012 Abstract The relative influences of language-related and memory-related constraints on the learning of novel words and sequences were examined by comparing individual differences in performance of children with and without specific deficits in either language or working memory. Children recalled lists of words in a Hebbian learning protocol in which occasional lists repeated, yielding improved recall over the course of the task on the repeated lists. The task involved presentation of pictures of common nouns followed immediately by equivalent presentations of the spoken names. The same participants also completed a paired-associate learning task involving word–picture and nonword–picture pairs. Hebbian learning was observed for all groups. Domaingeneral working memory constrained immediate recall, whereas language abilities impacted recall in the auditory modality only. In addition, working memory constrained paired-associate learning generally, whereas language abilities disproportionately impacted novel word learning. Overall, all of the learning tasks were highly correlated with domain-general working memory. The learning of nonwords was additionally related to general intelligence, phonological short-term memory, language abilities, and implicit learning. The results suggest that distinct associations between languageand memory-related mechanisms support learning of familiar and unfamiliar phonological forms and sequences. L. M. D. Archibald (*) School of Communication Sciences and Disorders, Elborn College, Western University, London, Ontario N6G 1H1, Canada e-mail: M. F. Joanisse Department of Psychology, Western University, London, Ontario N6G 1H1, Canada Keywords Implicit learning . Explicit learning . Specific language impairment . Working memory . Phonological short-term memory . Hebbian learning Both domain-specific mechanisms, such as phonological processing (Bailey & Snowling, 2002), and domaingeneral mechanisms, such as working memory (Gathercole & Baddeley, 1993), have been implicated in language development, and in word learning in particular. Learning an unfamiliar word taps multiple cognitive processes, including rapid generation of a lexical representation, retention of the serial order of constituent phonemes, and creation of long-term phonology-to-semantics connections (Gupta & MacWhinney, 1997). Of particular interest in the present study was the acquisition of novel phonological forms and sequences, a task considered to place high demands on both immediate memory processes and phonological processing. In the present study, we explored the relative influences of domain-general working memory and domain-specific phonological abilities on word learning by contrasting immediate recall and learning across visual and auditory modalities, as well as with familiar and unfamiliar phonological forms. We investigated domain-specific and domain-general constraints on word learning here by comparing the performance of children with developmental impairments in either language learning or working memory. Specific language impairment (SLI) refers to an unexpected delay in the onset or development of language, despite otherwise typical development and opportunities. Domain-specific deficits affecting all aspects of language learning are well documented for SLI groups, including impairments in phonological processing (Vandewalle, Boets, Ghesquière, & Zink, 2012) and vocabulary acquisition (Riches, Tomasello, & Conti-Ramsden, 2005). Although children with SLI perform poorly on working memory measures involving both the storage and manipulation of verbal materials (Archibald & Gathercole, 2006a), when working memory deficits are assessed using visuospatial Mem Cogn (2013) 41:268–280 measures, deficits are not consistently reported among SLI groups (Archibald & Gathercole, 2006b). In contrast, children with a specific working memory impairment (SWMI) perform poorly on both verbal and visuospatial working memory tasks but achieve age-appropriate scores on standardized language tests (Archibald & Joanisse, 2009). Our SWMI group was considered to have a domaingeneral working memory deficit because their impairments were established for working memory tasks involving the storage and processing of verbal and visuospatial materials, but not for short-term memory tasks requiring storage only. Both domain-specific and domain-general processes have been described as part of Baddeley and Hitch’s (1974) model of working memory, or the ability to briefly store and process information. According to this model, working memory includes two domain-specific slave systems that handle the temporary storage of phonological and visuospatial materials (the phonological loop and the visuospatial sketchpad, respectively). The third component of working memory is the central executive, which is a controlled attentional resource responsible for high-level processing activities and for the coordination of activities within working memory. Suggestions that the central executive is a domain-general resource are supported by findings of a common processing efficiency factor underlying both verbal and visuospatial working memory tasks (Chein, Moore, & Conway, 2011; Kane et al., 2004). The children identified with SWMI in our previous study (Archibald & Joanisse, 2009) were considered to have a deficit in the domain-general central executive component of working memory because their impairments were established for working memory tasks involving the storage and processing of verbal and visuospatial materials, but not for short-term memory tasks requiring storage only. Short-term and working memory tasks are distinguished by whether they involve the brief retention of information in short-term memory only (e.g., serial recall of words) or involve additional processing involving the central executive (e.g., reversing list order prior to recall). As well, serial recall tasks involving long lists that exceed an individual’s shortterm memory capacity share common variance with other complex working memory tasks (Unsworth & Engle, 2006). It has been suggested that such supraspan tasks additionally tap domain-general resources in working memory to retrieve items displaced from short-term memory (Unsworth & Engle, 2006). Both simple span measures of phonological short-term memory (Gupta & MacWhinney, 1997) and complex verbal working memory tasks (Daneman & Carpenter, 1983) have been linked to language abilities. Visuospatial short-term memory tasks, however, have not been found to be related to language processing (Adams, Bourke, & Willis, 1999; but see Phillips, Jarrold, Baddeley, Grant, & Karmiloff-Smith, 2004). As a result, in the present study we focuse (...truncated)