Original Article Interaction Between Working Memory and Long-Term Memory A Study in Children With and Without Language Impairment Klara Marton1,2 and Naomi Eichorn1 1The Graduate School and University Center of the City University of New York, NY, USA, 2Barczi Gusztav College of Special Education of Eotvos Lorand University, Budapest, Hungary Abstract. Individual differences in working memory have been related to interactions between working memory and long-term memory (LTM). The present study examined this interaction in children with and without language impairment. We used two listening span tasks and two nonword repetition tasks. The results suggest a strong interaction among age, language status, and task complexity. Children with specific language impairment showed consistently poor performance across tasks and indicated a weakness in using long-term knowledge to support working memory performance. The findings show that these children do not benefit from various manipulations designed to enhance working memory performance via LTM support due to a combination of inefficiencies in maintaining and updating items in working memory and retrieving information from LTM, in part because of their poor resistance to interference. Keywords: working memory, long-term memory, strategy use, children, specific language impairment Findings on working memory (WM) functioning show sig- Interaction Between WM and LTM: nificant individual differences in both children and adults, as well as in clinical populations (Coady & Evans, 2008; A Developmental Perspective Unsworth, Brewer, & Spillers, 2013; Was & Woltz, 2007). One of the most significant contributing factors to Most cognitive models that describe the association these individual differences is the interaction between between WM and LTM are based on data from adults WM and long-term memory (LTM). Understanding the nat- (e.g., Oberauer, 2005; Unsworth & Engle, 2007). Develop- ure of this interaction in children is important from a theo- mental scientists often use these models in WM studies retical point of view, as well as from an educational with typically developing children (e.g., Magimairaj, Mont- perspective. Although a number of studies (e.g., Marton gomery, Marinellie, & MacCarthy, 2009) because there is & Schwartz, 2003; Montgomery, 2000) reported a deficit no comprehensive developmental model to describe the This document is copyrighted by the American Psychological Association or one of its allied publishers. American Psychological This document is copyrighted by the in WM and related executive functions in children with interaction between WM and LTM and account for age- This article is intended solely for the personal use of individual user and not to be disseminated broadly. specific language impairment (SLI), underlying factors related changes. Most developmental studies examined per- contributing to the WM capacity deficit in these children formance in one of the memory systems. Only a few have not been identified. researchers investigated specific memory functions in both Individual differences in WM capacity reflect both vari- systems. Lloyd, Doydum, and Newcombe (2009) examined ations in the ability to actively maintain and update infor- familiarity and recollection within a recognition paradigm mation over a limited period of time and the ability to and found that young children (age 4) produced an retrieve task-relevant information from LTM (Unsworth increased false alarm rate for recollection in LTM com- & Engle, 2007). Efficient retrieval of task-relevant items pared to WM tasks. The authors concluded that young chil- is particularly difficult when interfering information is pres- dren show a weakness in retrieval of relevant information ent (Oberauer, 2005). Individuals with low WM capacity from LTM. Studies on school-age children revealed that tend to retrieve more irrelevant items because they are more both WM and long-term knowledge predict learning out- susceptible to interference, which leads to less accurate comes but the interaction between the two systems was recall of target items. not examined in any of these studies (e.g., Alloway, 2009). Zeitschrift für Psychologie 2014; Vol. 222(2):90–99 Ó 2014 Hogrefe Publishing DOI: 10.1027/2151-2604/a000170 K. Marton & N. Eichorn: Memory and Language in Children 91 An important phenomenon that has recently received an increase in task complexity, children with SLI either per- considerable attention in the developmental literature is form similarly to younger children or show a distinct per- the ability to resist interference (Unsworth et al., 2013), formance pattern. This WM deficit in children with SLI which improves gradually during childhood and into ado- has been associated with difficulty with concurrent process- lescence (Schleepen & Jonkman, 2009). Interference may ing and storage (Marton & Schwartz, 2003; Montgomery, influence both memory systems, negatively affecting the 2000); poor inhibition, particularly resistance to interfer- maintenance and updating of relevant items in WM, as well ence (Marton et al., in press); and slower processing speed as the retrieval of information from LTM. Effective resis- (Miller, Kail, Leonard, & Tomblin, 2001). Based on these tance to interference is associated with larger WM capacity findings, we may conclude that WM shows a multifaceted because relevant and irrelevant item representations com- deficit in children with SLI; however, none of these studies pete for the same limited WM capacity. examined interactions between WM performance and LTM The majority of developmental research examining WM retrieval in children with SLI. and its relation to LTM used variations of two basic task A second large set of studies focused on phonological types: verbal span tasks and nonword repetition (NWR) WM in children with SLI. These studies used various ver- tasks. Although both tasks can be used to examine the rela- sions of NWR tasks and consistently found that children tionship between WM and LTM, they target different with SLI performed more poorly than their peers (Marton aspects of WM. Verbal span tasks measure capacity limita- & Schwartz, 2003; Montgomery & Windsor, 2007). An tions in processing complex linguistic information and important aspect of NWR with regard to LTM is the word- require active maintenance and updating of items in WM, likeness effect. Repetition of nonwords with no meaningful as well as systematic searches in LTM. Studies using verbal syllables is a measure of phonological WM, whereas more span tasks show that children’s WM performance improves wordlike nonwords reflect the support from LTM with age and that these developmental changes are associ- (Gathercole, 1995). Casalini and colleagues (2007) exam- ated with faster speed of processing (Kail, 2000), larger ined the wordlikeness effect using morphemes and com- storage capacity (Magimairaj et al., 2009), and more effi- pared nonwords with no meaning to nonwords with cient strategy use (Fatzer & Roebers, 2013). meaningful morphemes. Although children with SLI per- Studies using NWR tasks focus on storage and process- formed more poorly than TLD children, they showed a sim- ing of phonological information and its relationship to ilar profile of recall, with highest recall for real words, LTM. This interaction has been examined using nonwords followed by nonwords with real morphemes, followed by with high and low phonotactic probability (frequency of nonwords with no meaningful morphemes. These findings certain phoneme combinations; Edwards, Beckman, & reflect facilitatory effects of LTM on phonological WM. Munson, 2004) and nonwords with varying degrees of wordlikeness (Gathercole, 1995). Improved NWR skills in older compared to younger children have also been asso- ciated with the development of phonological sensitivity (Morra & Camba, 2009) and vocabulary (Edwards et al., The Goal of the Current Study 2004). Older children show more structured and stable We examined the interaction between WM and LTM in word representations in LTM than younger children and children with and without SLI in two experiments. We these factors facilitate NWR. chose the Traditional Listening Span Task (TLST) and Tra- ditional Nonword Repetition Task (NWR) as reference tasks because these measures are widely used in the SLI lit- erature. We also developed modified versions of each task WM Capacity in Children With Specific to more directly examine the contribution of LTM to WM. In Experiment 1, we administered a TLST and an Active Language Impairment (SLI) Listening Span Task (ALST), in which we measured chil- This document is copyrighted by the American Psychological Association or one of its allied publishers. American Psychological This document is copyrighted by the dren’s performance on items they had activated and This article is intended solely for the personal use of individual user and not to be disseminated broadly. Children with SLI show significant limitations in WM retrieved prior to administration of the span task. In Exper- capacity compared to their typically developing (TLD) iment 2, we compared performance on traditional NWR to peers (Marton & Schwartz, 2003; Montgomery, 2000) and perform poorly on verbal span tasks (Marton & a modified NWR in which nonwords contained one mono- syllabic meaningful word, with either high or low fre- Schwartz, 2003; Montgomery, 2000). Compared to TLD quency of occurrence. Based on previous findings in participants, children with SLI exhibit diminished primacy TLD children,