Introduction Bilingualism—a term often used interchangeably with multilingualism—is an interdisciplinary and multifaceted field. Researchers in bilingualism are interested in studying the acquisition, production, processing, and comprehension of two or more languages (Bhatia, 2018). In brief, bilingualism is concerned with the coexistence of more than one language system within an individual (Hakuta, 2009). For humans, the ability to learn and use multiple languages is not new, as evidenced by the many references to bilingualism in early writings such as Panini’s grammar of Sanskrit and religious texts. Similarly, the ability to translate and interpret between languages is not new. When considering that translation and interpreting are processes con ducted by bilinguals, it is surprising that the fields of bilingualism and translation and interpret ing studies (TIS) have developed their own research trajectories, often with very little dialogue between the two disciplines. The Routledge handbook of translation, interpreting, and bilingualism is the first to bring together the related fields of TIS and bilingualism under the same cover. Given the extreme breadth of these interdisciplinary fields, which would be very difficult to cover within the same hand book, we specifically focus on cognitive aspects. Research on bilingualism and TIS from cog nitive approaches have carved their own subdiscipline as can be seen when referencing them: ‘Cognitive Bilingualism’ (Schwieter & Ferreira, 2018), also referred to as ‘bilingual process ing’ (Schwieter, 2015), and cognitive translation and interpreting studies (CTIS) (Schwieter & Ferreira, 2017; Xiao & Muñoz Martin, 2020). The overlapping nature between bilingualism and TIS, along with the fact that both disciplines are widely studied through a cognitive lens, demonstrates their ability to complement and learn from one another. Overview of the handbook Following this introductory chapter, Part II of the handbook is dedicated to theories and meth ods. In Chapter 2, Dong presents an in-depth description of the unique bilingual profile of translators and interpreters. The chapter takes the general bilingual population (i.e., “typical” bilinguals who are not translators or interpreters) as a reference point to compare and contrast the uniqueness of translators and interpreters. The author specifically considers the cognitive demands that translation and interpreting involve in her characterization of this highly skilled bilingual population. Chapter 3, by Festman and Poarch, offers an overview of prominent theo ries and models in cognitive bilingualism. Key topics are discussed, such as the cognitive control required for bilingual language processing and the consequences of bilingualism for cognition. Marín García (Chapter 4) reviews theories and models in CTIS and bilingualism by taking readers on a historical journey from the 1960s, and process-oriented research, to the state of the field today. Sophisticated models of the cognitive underpinning of translation are based on extremely sensitive data-gathering methods which offer significant insight on issues such as mediators’ typing, stress, emotions, brain plasticity, and peer-to-peer interaction. Marín García advocates that CTIS holds significant implications for the language industry, technological advancements, and other enterprises. In Chapter 5, Janikowski and Chmiel elaborate on some of the primary research methods used in CTIS and bilingualism. The chapter first discusses physiological measures such as MRI, EEG, eye-tracking, and galvanic skin response, and psy cholinguistic tasks such as priming, lexical decision, picture naming, and the Stroop, Simon, and Flanker tasks. Janikowski and Chmiel also report on traditional methods (e.g., keystroke logging, corpora, interviews, etc.) as these measures have implications for cognitive-oriented research. Neurocognitive aspects of CTIS are the topics of interest in Part III. In Chapter 6, García and Kogan offer insights into how interlingual reformulation can elucidate our understanding of the bilingual brain. Interlingual reformulation is any neurocognitive activity where language input is generated into a different language, irrespective of modality (García, 2019). The authors first discuss the neural organization of bilinguals’ linguistic systems. They then address the asym metries between the two systems as hypothesized in pioneering models of the bilingual memory and the consequences of the co-activation of two languages in one mind. The chapter ends with sections on the role of interlingual reformulation in second-language (L2) word learning and brain plasticity. Chapter 7, by Korpal and Rojo López, reviews studies using physiological measures to examine language processes in translation and interpreting. The authors address the concept of embodied cognition and what the interaction between cognition and physiology reveals about translation and interpreting processes. The chapter elaborates in more detail on many of the physiological methods discussed by Janikowski and Chmiel (Chapter 5). These sections report on pioneering and ongoing work using these measures, along with a discus sion on future research directions in work employing physiological methodologies. Finally, in Chapter 8, Calvo presents evidence for brain plasticity among young bilingual adults and its critical role in translation and interpreting. The author critically examines current research on experience-dependent neural plasticity among translators and interpreters and proposes avenues for future research. In Part IV, the handbook then turns to discuss topics related to the cognitive architec ture of translation and interpreting processes. Chapter 9, by Moser-Mercer, opens the section with a discussion on working memory and simultaneous and consecutive interpreting. The chapter begins by presenting working memory models and their implications for interpreting. Following this, Moser-Mercer reviews issues related to working memory, including updating and cognitive control, along with the notion of an interpreter advantage for working mem ory capacity. In Chapter 10, Zhao, Chen, and Dong discuss how interference is controlled in interpreting. They specifically explore how interference control in interpreting differs from that in general bilingual processing. The chapter begins by reviewing theories of bilingual lan guage control and discussing how these theories can be used to explain interference control in interpreting. Zhao et al. then review the Attentional Control Model in interpreting (Dong & Li, 2020) with a particular emphasis on the model’s predictions related to how interpreters may control interference arising from activated languages. Chapter 11, by Liao and Kruger, presents the topic of cognitive processing of subtitles. The chapter opens with a brief overview of early research on how subtitles are processed. Against this backdrop, the authors discuss how a more complete picture of subtitle processing is emerging which uses innovative methods such as eye-tracking to investigate various aspects of subtitled products. They then review new research trajectories in related disciplines and topics (e.g., reading, multimedia learning, and multitasking). Finally, the authors identify uncharted territory for future work on subtitle processing and other audiovisual translation products. In Chapter 12, Ferreira and Miglo discuss the role of identity in CTIS. The authors first review how the two constructs of identity and bilingualism have been researched and interpreted. The chapter then transitions to assess research in CTIS on language production and comprehension, discourse processing, memory, attention, and expertise. Finally, they present a critical discussion on the benefits of examining identity and bilingualism in order to better understand how trans lation and interpreting tasks are performed. False belief and perspective taking are the topics of focus in Chapter 13 by Diaz. The chapter brings to light the importance of considering sociolinguistic characteristics and psycholinguis tic processes in research in CTIS and bilingual development. Diaz also reviews brain-imaging studies that examine the relationship between Theory of Mind and translation and interpreting processes. These topics include the activation of Theory-of-Mind-related brain areas during translation tasks and the activation of brain areas implicated in perspective taking when trans lating remarks whose meanings depend on context. Part IV concludes with Chapter 14, in which Rojo López and Caldwell-Harris discuss emotion processing in bilingual language use and translation processes. The chapter begins with a look at how individuals may feel a stronger emotional connection with their first language compared to a foreign language. Following this, the authors examine how emotions are processed in two languages and how decision-making is affected by the language used. The chapter concludes with a dialogue on implications for professional practice and future research. The cognitive dynamics involved in TIS is the theme of Part V, which starts with Lörscher’s discussion on research development in translation processes since the mid-1980s. In the chapter, Lörscher presents a review of three research projects related to translation processes and how translation problems are solved. He explains the concept of natural translation and elaborates on models explaining the development of translation competence. The author also advocates for combining introspective protocols with other measures to better investigate translation pro cesses. Chapter 16, by Rossi, Iniesta, and Nakamura, focuses on issues related to age, bilingual ism, and cognition in translators and interpreters. They firstly review the dynamics of language processing, and how aging and neurophysiological changes in the brain are related. The authors then discuss how languages may remain relatively intact as over the lifespan and how bilin gualism might have a positive effect on cognitive aging. Finally, the chapter reviews the effects and dynamics of translation and interpreting while exploring critical aspects such as L2 age of acquisition and relative experience with translation and interpreting. In Chapter 17, by Seeber and Amos, the authors discuss three key terms in CTIS, namely, capacity, load, and effort. The authors refer to capacity as the maximum amount of cognitive resources that can be used by a mental system, load as the quantification of the processing demands required by tasks, and effort as the actual allocation of cognitive resources that are applied to tasks. They present a review on how monolingual tasks have been used to investi gate an individual’s capacity to understand and produce language. The authors then consider how multilingual tasks have been used to assess language comprehension and production, code mixing and code switching, written translation, post-editing, sight translation, consecutive interpretation, and simultaneous interpretation. Throughout their discussions, the concepts of capacity, load, and effort are interwoven, demonstrating their significant potential to reveal nuances of language processing, particularly with respect to the speed, modality, and direc tionality. Togato and Macizo Soria’s contribution (Chapter 18) is on cognitive flexibility. The authors begin by explaining its original conceptualization as a switching ability and examine work investigating whether it is domain-specific or domain-free ability. They also discuss cogni tive flexibility as dependent on the person’s capacity to switch between two conceptualizations, which occurs due to a person’s capacity to learn and improves with experience. The authors also explain how attentional processes are related to cognitive flexibility and their relationship between cognitive flexibility and working memory in interpreters. The handb
