Working Memory in Second Language Learning

Alan Baddeley

Introduction

The multi-component model of working memory (WM) was developed with the dual aims of providing a framework for the basic understanding of human memory, and at the same time providing a bridge to application beyond the laboratory. One of the earliest and, in my view, most successful of such applications was to language learning, principally to the acquisition and development of vocabulary in children (Baddeley et al., 1998), and also to second language learning (Atkins & Baddeley, 1998). As is clear from the current volume, research on WM and second language learning has flourished in the years since my own rather minimal involvement, and hence I was delighted to hear of the present enterprise, and to lend my support through writing this introductory chapter to express my speculative thoughts on the possible implications of the multi-component view of WM for second language learning.

While it would have been very nice to read the contributions and subsequently comment on them, the timing clashed with the process of revising and updating our memory text (Baddeley et al., 2015). My initial agreement was to write a Preface that envisaged little more than enthusiastic support of this particular application of the WM model. I was, however, tempted by the editor's suggestion that I might outline the current state of the multi-component model, and in doing so thought it would be interesting to think about second language learning and speculate as to how the various current components of the model might be involved. I should emphasise, however, that what follows is simply a brief account of the current model (a more extended discussion can be found in Baddeley [2012]), together with some initial thoughts that may well be proved misguided by the chapters that follow. If so, I shall simply fall back on the observation that progress is often made by discovering points where our predictions are clearly wrong.

Evolution of the Multi-Component Model

Our WM model has its roots in the proposal that short-term memory (STM), principally verbally based, played a useful role in cognition more generally, a view first presented by Broadbent (1958) and developed much more extensively by Atkinson and Shiffrin (1968). Our own work (Baddeley & Hitch, 1974) was prompted by difficulties encountered by this approach in dealing both with links to long-term memory (LTM) and with data from patients whose impaired verbal STM had surprisingly little impact on their broader cognition. Our own studies, relying heavily on dual task methods, led us to propose the model shown in Figure 1.1, which assumes an attentionally limited control system, the central executive, aided by two temporary storage systems, one specialised for acoustic and language stimuli, and the other counterpart the visuospatial sketchpad.

Further development was spurred by the challenge of finding an evolutionary function for the phonological loop that might prove more plausible than remembering telephone numbers. Our search was helped by access to a patient, PV, with a very pure phonological loop deficit. We first tested the hypothesis that the loop was necessary for language comprehension, but found little evidence of impairment, except for certain convoluted sentences explicitly designed to rely on the phonological loop (Vallar & Baddeley, 1987). We then tested the hypothesis that the phonological loop might have evolved for language acquisition, finding that our patient was greatly impaired in acquiring vocabulary in a foreign language, Russian (Baddeley et al., 1988). We went on to show that procedures interfering with the phonological loop function disrupt the acquisition of foreign language vocabulary but not memory for meaningful word pairs in healthy participants (Papagno et al., 1991), and that polyglots who have acquired several languages tend to show enhanced phonological loop capacity (Papagno & Vallar, 1995), while otherwise extremely able people with a reduced verbal STM also tend to have difficulty in acquiring foreign vocabulary (Baddeley, 1993). Furthermore, extensive research by Susan Gathercole and myself has shown a clear link between native language vocabulary learning in children and phonological memory (see Baddeley et al. [1998] for a more detailed account).

As a result of this line of work, we modified the basic model to that shown in Figure 1.2. The principal difference is a clear link between the phonological loop and phonological LTM, a link that operates in both directions; the phonological loop facilitates the acquisition of new words, and in due course the richer the available array of existing words, the easier it is to use these to help acquire new items. We speculate that a similar link will occur between the sketchpad and visuospatial semantics, although this has been little investigated so far.

The next version of the model was also driven by the study of language and, in particular, the very strong relationship between prose comprehension and the...