Introduction
Individual differences that have an impact on the processes and outcomes of second language (L2) learning have been thoroughly investigated; but, until recently, the study of language learners with additional needs was at the periphery of both second language acquisition (SLA) and language teaching pedagogy (e.g. Nijakowska, 2010Footnote *; Kormos & Smith, Reference Kormos and Smith2012; Kormos, 2017Footnote *). Specific learning difficulties (SLDs), which affect between 5 and 15% of the population (Drabble, Reference Drabble2013), often have an impact on how additional languages are acquired. Therefore, in order to create an inclusive language learning context and set up effective instructional programmes, it is essential to understand how children with SLDs develop their competence in additional languages.
Specific learning difficulties are conceptualized differently in various educational models of disabilities. The deficit model views disabilities as deficiencies and a series of obstacles in individuals' lives. The educational consequence of such models is that the main focus of provision is on meeting children's individual needs. In this model, little consideration is given to the barriers that hinder successful learning (Thomas & Loxley, Reference Thomas and Loxley2007). The interactional view of disabilities (Frederickson & Cline, Reference Frederickson and Cline2002; Norwich, Reference Norwich and Reid2009) highlights that disabilities impede full participation in society because individuals' difficulties interact with barriers in the environment. Taking this perspective allows us to understand the strengths and weaknesses of language learners with SLDs and the interactions between students and their learning contexts. In many previous studies in the field of SLA, SLDs have been considered similar to cognitive individual difference variables. Consequently, many of these studies have been either implicitly or explicitly based on deficit models of disability. This type of research has mostly focused on individual learners and the effectiveness of instructional programmes specifically designed for language learners with SLDs (e.g. Pfenninger, 2015Footnote *). Studies conducted in this paradigm have tended to use questionnaire surveys and assessment tests in L1 and L2, which were administered to language learners with SLDs to compare their disposition to learning (e.g. motivation: Kormos & Csizér, 2010Footnote *; anxiety: Piechurska-Kuciel (2008)Footnote * and language performance (e.g. Sparks, Ganschow, & Pohlman, 1989Footnote *; Helland & Kaasa 2005Footnote *). Research that has examined the processes of learning additional languages from the learners' own perspectives remains scarce. Furthermore, studies that view language learners with SLDs as a diverse group interdependent with the social and instructional context are rare and primarily rely on interview data (e.g. Kormos, Csizér, & Sarkadi, 2009Footnote *; Csizér, Kormos, & Sarkadi, 2010Footnote *). The barriers present in current language teaching practices and educational policies have remained largely under-researched (for exceptions, see Abrams, Reference Abrams2008; Cobb, 2010Footnote *). However, recently, attention has turned to the investigation of language teachers' self-efficacy, attitudes and beliefs on inclusive teaching practices (e.g. Kormos & Nijakowska, Reference Kormos and Nijakowska2017), content knowledge and professional training needs (e.g. Nijakowska, Reference Nijakowska, Pawlak and Aronin2014), and inclusive instructional practices (e.g. Kahn-Horwitz, Reference Kahn-Horwitz2015, Reference Kahn-Horwitz2016; Russak, Reference Russak2016). This is an important area of research, as Csizér et al.'s 2010Footnote * study highlights the significant role teacher attitudes, practices and expertise play in the language learning experience of dyslexic students.
Different conceptualizations of SLDs also result in the fact that labels used to describe SLDs vary in different geographical and professional contexts. The 5th edition of the Diagnostic and statistic manual of mental disorders of the American Psychiatric Association (DSM-5 APA, 2013) uses the term specific learning disorder. In psychological research and legislation in Canada, Australia and the United Kingdom, the terms learning disability and learning difficulty are applied. The labels learning disorder and learning disability are appropriate within the deficit model of disability where the emphasis is on discovering the exact nature and underlying causes of SLDs. In this paper, I will use the term specific learning difficulty, which is in line with the interactional view of disabilities. This will help us explore how individuals' characteristics and obstacles in the educational context interact with – and impact on – processes of multilingual language development. In this research timeline, I will use the definition of SLDs provided by DSM-5 (APA, 2013) because it is one of the most widely accepted and best empirically supported conceptualizations of SLDs. DSM-5 groups various sub-types of SLDs, such as dyslexia (word-level reading difficulty) and dyscalculia (mathematics disability), under the joint umbrella term of SLDs. This acknowledges the large overlap between these types of learning difficulties. It also creates sub-categories of SLDs, two of which are particularly relevant for language learning: ‘specific learning disorder in reading’ and ‘specific learning disorder in written expression’. Within SLDs in reading, DSM-5 distinguishes word-level decoding problems (dyslexia) and higher-level text comprehension problems (specific reading comprehension impairment) (see also Cain, Oakhill, & Bryant, Reference Cain, Oakhill and Bryant2004). SLD in writing comprises problems with spelling, punctuation and grammatical accuracy, and clarity and organization of written expression. In some countries, Attention Deficit and Hyperactivity Disorder (ADHD) is also considered to be an SLD (e.g. in the UK). In DSM-5 it is classified separately from specific learning disorders and is listed under neurodevelopmental disorders, but its description is immediately followed by SLDs to signal their overlapping features. As the name suggests, the two major features of ADHD are inattention and hyperactivity. ADHD can also be the cause of learning and literacy-related difficulties. In this research timeline, I have included existing studies on language learners with ADHD (e.g. Sparks, Ganschow, & Patton). Where studies involved participants with more generalized SLDs, I apply the term ‘SLD’, but where research was conducted specifically on language learning with dyslexia, I use the term ‘dyslexia’.
The aim of this article is to provide a timeline of studies that have addressed the issue of the role of SLDs in L2 development and teaching and to show how research on this topic has evolved over time. To this end, the timeline begins with early studies that examined the relationship between language learning difficulties, L2 learning aptitude and SLDs. Not long after awareness of the role of SLDs in learning additional languages had been raised, researchers also started to investigate the effectiveness of various instructional programmes to enhance the L2 skills of learners of additional languages. Early research in this field was primarily conducted by cognitive psychologists who applied diagnostic tools and remedial teaching techniques applied in first language (L1) literacy education. A large number of these studies, many of which can be placed within the deficit model of disabilities, did not specifically focus on SLDs but examined broader samples of L2 learners in which predictors of L1 literacy skills were normally distributed. These studies have analysed the role of underlying cognitive predictors on L2 literacy outcomes and produced important results on how SLDs can be identified in multilingual children in various contexts (for an overview, see Geva & Wiener, Reference Geva and Wiener2014; Kormos, 2017Footnote *). The history of research on SLDs in the field of SLA and language teaching only spans the last three decades. In this overview, I focus on three key issues: (1) the cognitive and (2) affective impact of SLDs on L2 learning processes and outcomes and (3) teaching languages to students with SLDs. Due to the relatively large number of theoretical and empirical studies that have addressed these issues, it is not possible, and also not intended, to provide a comprehensive account of all individual studies in these three areas. Therefore, the timeline almost exclusively contains studies where participants had an official identification of their SLDs and excludes a large amount of research where the contribution of various underlying cognitive and linguistic factors in L2 development was examined in normally distributed samples. This timeline does not include studies on the identification of SLDs in multilingual speakers (for an overview, see Geva & Wiener, Reference Geva and Wiener2014) and research on how the L2 skills of learners with SLDs can be assessed (for an overview, see Kormos, 2017Footnote *). In this timeline, studies are categorized according to the following themes:
1. The cognitive effects of SLDs on L2 learning processes and outcomes
A. Theoretical overview
B. Relationship between language learning difficulties and SLDs
C. Language learning aptitude and SLDs
D. The effect of SLDs on L2 production and comprehension
2. Affective factors in the language learning processes and outcomes of individuals with SLDs
A. Language learning motivation of students with SLDs
B. Anxiety and SLDs
3. Teaching languages to students with SLDs
A. Pedagogical overview
B. Studies on the effectiveness of multi-sensory instruction
C. Research on inclusive language teaching
D. Research on the benefits of bilingual education
Judit Kormos is a Professor of Second Language Acquisition at Lancaster University, UK. She was the chief investigator of a project that explored the foreign language learning processes of dyslexic students in Hungary She is the co-author of Teaching languages to students with specific learning differences (2012, Multilingual Matters) and the author of Understanding the second language learning processes of students with specific learning difficulties (2017, Routledge). She worked on a European Commission sponsored teacher training project in the field of dyslexia and language learning www.dystefl.eu and is the lead educator of the Dyslexia and Foreign Language Teaching Massive Open Online Learning Course offered by FutureLearn. She has also published several research articles on the effect of dyslexia on the process of SLA.
