Bilingual Language Processing

Abstract

Psycholinguistic approaches to examining bilingualism are relatively recent applications that have emerged in the 20th century. The fact that there are more than 7,000 current languages in the world, with the majority of the population actively using more than one language, offers the opportunity to examine language and cognitive processes in a way that is more reflective of human nature. While it was once believed that exposing infants and children to more than one language could lead to negative consequences for cognition and overall language competence, current evidence shows that this is not the case. Among the many topics studied in psycholinguistics and bilingualism is whether two language systems share an integrated network and overlap in the brain, and how the mind deals with cross-linguistic activation and competition from one language when processing in another. Innovative behavioral, electrophysiological, and neuroscientific methods have significantly elucidated our understanding of these issues. The current state of the psychology and neuroscience of bilingualism finds itself at the crossroads of uncovering a holistic view of how multiple languages are processed and represented in the mind and brain. Current issues, such as exploring the cognitive and neurological consequences of bilingualism, are at the forefront of these discussions.

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Bilingual Language Processing
John W. Schwieter, Wilfrid Laurier University and McMaster University
https://doi.org/10.1093/acrefore/9780199384655.013.370
Published online: 21 August 2024
Summary
Psycholinguistic approaches to examining bilingualism are relatively recent applications that have emerged in the
20th century. The fact that there are more than 7,000 current languages in the world, with the majority of the
population actively using more than one language, offers the opportunity to examine language and cognitive
processes in a way that is more reflective of human nature. While it was once believed that exposing infants and
children to more than one language could lead to negative consequences for cognition and overall language
competence, current evidence shows that this is not the case. Among the many topics studied in psycholinguistics
and bilingualism is whether two language systems share an integrated network and overlap in the brain, and how
the mind deals with cross-linguistic activation and competition from one language when processing in another.
Innovative behavioral, electrophysiological, and neuroscientific methods have significantly elucidated our
understanding of these issues. The current state of the psychology and neuroscience of bilingualism finds itself at
the crossroads of uncovering a holistic view of how multiple languages are processed and represented in the mind
and brain. Current issues, such as exploring the cognitive and neurological consequences of bilingualism, are at the
forefront of these discussions.
Keywords: bilingualism, psycholinguistics, language and cognition, language and brain, psycholinguistic methods,
neuroscientific methods, bilingual advantage
Subjects: Cognitive Science, Neurolinguistics, Psycholinguistics
1. Introduction
Psycholinguistics, a branch of cognitive science and linguistics, examines the cognitive processes
involved in language production, perception/comprehension, and acquisition. It is also concerned
with the mental representation of language(s) in the human mind. Psycholinguistics can trace its
emergence from the work of Wilhelm Wundt (1832–1930), who is traditionally known as the
“father of experimental psychology.” The term “psycholinguistics” was perhaps first mentioned
by Jacob Kantor (1936) in his book An objective psychology of grammar and gained additional
notoriety through the paper entitled “Language and psycholinguistics: A review” by Kantor’s
student, Nicholas Pronko (1946). While at first psycholinguistics developed by studying the
cognitive mechanisms of language use among monolinguals, it soon became of great interest to
researchers in bilingualism.
Although some of the earliest accounts of bilinguals can be traced back to the Sanskrit philologist
and scholar Pāṇini in the 6th century BCE, it was not until the mid-20th century that bilingualism
entered a pioneering phase. Researchers Weinreich (1953), Haugen (1953), and Mackey (1967)
John W. Schwieter, Wilfrid Laurier University and McMaster University

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have been seen as foundational figures in the early stages of the field of bilingualism. These major
works continue to impact the field: Weinreich’s work presented an analysis of linguistic,
sociolinguistic, and psycholinguistic approaches to two languages in contact; Haugen’s pre-
generative grammatical framework of code-switching was based on a case study of Norwegian in
the United States; and Mackey’s research, similar to Weinreich’s arguments, offered key
theoretical and empirical questions about bilingualism, many of which continue to be relevant.
According to the 26th edition of Ethnologue (Eberhard et al., 2023), there are 7,168 languages
actively used across the globe—17 more than a year before—and within this context, bilingualism
is more prevalent than monolingualism. In contemporary research, the term bilingualism (and
individuals referred to as bilinguals) reflects two languages. However, the term is often used
interchangeably to describe multilinguals, trilinguals, and polyglots. While the nuances of
defining this complex phenomenon are beyond the scope of this article, the reader may wish to
refer to de Bot (2019) who offers an in-depth analysis and description of “who is bilingual” and
“what is bilingualism.”
Until the latter part of the 20th century, interest in bilingualism had played second fiddle to
monolingualism due to the complicated nature of the former. This notion can be clearly seen and
perhaps exasperated by statements by eminent scholars such as Jakobson et al. (1953), who
identified bilingualism as a fundamental problem in linguistics, and Chomsky (1986), who argued
that the pure idealized form of language knowledge should be of primary interest rather than
bilingualism per se. Although it is accurate that bilingualism presents a more complex individual,
social, political, educational, and psychological situation, the consequences of these declarations
and others led to an extension of hypotheses on bilingualism based on observations and
processes of monolinguals and the inaccurate description of a bilingual being “two monolinguals
in one brain,” a notion that has been debunked by Grosjean (1989), among others.
Moreover, in the early part of the 20th century and before, researchers believed that bilingualism
could have adverse consequences on early childhood development. It was argued that the brain
had a limited capacity for language and, therefore, overloading it with the task of acquiring more
than one language system could lead to serious cognitive and linguistic impairments in children.
The Linguistic Deficit Hypothesis (Hakuta, 1986), for instance, held that bilingual children not
only would likely suffer from “semilingualism” (i.e., the lack of native-like proficiency in both
languages) but would also be more susceptible than monolingual children to language delays (see
Umbel & Oller, 1994 for a discussion) and even low intelligence or schizophrenia (Weinreich,
1953).
Soon after these claims, a more accurate and holistic view of bilingualism appeared, one which no
longer depicted bilingualism as a by-product or extension of monolingualism. Among the major
theories that led to this shift was the Linguistic Augmentation Hypothesis by Peal and Lambert
(1962) and their findings that bilingual children displayed more cognitive flexibility and
performed better on verbal and nonverbal measures than their monolingual peers. Their study
provided compelling evidence that the previously reported negative effects of exposure to and
acquisition of more than one language were premature and misguided by theoretical and

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methodological flaws. Peal and Lambert’s pioneering study thus revolutionized research on
bilingualism and brought to light a positive conception of acquisition of more than one language.
By the 1990s, a surge in studies from psycholinguistic perspectives emerged.
In this growing body of research are studies attempting to characterize relative levels of a
bilingual’s languages. Language proficiency is notoriously difficult to define and measure (see
Austin et al., 2019 for a review). According to Cummins (1981), language proficiency involves two
types of skills: basic interpersonal communication skills and cognitive/academic language
proficiency. Whereas the former can be viewed as the ability to interact in context-embedded
(e.g., personal conversations) situations, the latter relies on the ability to use and manipulate
language in decontextualized settings (e.g., classrooms). Achieving “native-like
proficiency” (i.e., the ability of non-native speakers to comprehend and produce language in a
manner that closely resembles the performance of native speakers) in these two domains of
proficiency is a challenging endeavor. Beyond traditional metalinguistic measures,
psycholinguistic research techniques, such as reaction time and eye-tracking experiments, are
used to investigate how nonnative speakers process language at various levels, including
phonological, morphosyntactic, and semantic processing. By comparing the processing patterns
of nonnative speakers to those of native speakers, researchers are gaining more insight into the
nature of bilingual language processing.
2. Mental Activation of Multiple Languages
The activation and representation of multiple languages intersects with the psychology and
neuroscience of linguistics in critical ways. According to Lust (2011), these issues:
involve psycholinguistics because any particular manifestation of language during
language acquisition is revealed through the cognitive and psychological infrastructure of
the mind and brain during “hearing” and “speaking” in real time, potentially within a
visual modality as in sign languages, thus always involving language processing
integrated with language knowledge. They [also] involve neurolinguistics, not only
because the knowledge and use of language must in some way relate to its biological and
neural instantiation in the brain, but also because explanations of the gradual course of
language acquisition over time must critically evaluate the role of biological change. (p.
56)
With respect to the mental activation and access of languages among bilinguals, there is a clear
distinction from that of monolinguals. For instance, unlike monolinguals, bilinguals are able to
choose in which language to speak based on complex, unconscious cognitive processes. These
processes, however, are not random. Grosjean (2010) hypothesizes that the control of language
choice is determined by four key characteristics: the participants involved in the communicative
act, the situation in which bilinguals find themselves, the topic of discourse, and the function of
interaction.

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In Grosjean’s (1998, 2001) elaboration of language modes, a notion which refers to the state of
activation of a bilingual’s languages that is determined by communicative and environmental
factors, the author proposed that bilinguals can place themselves on a continuum of three
language states: a monolingual mode, an intermediate mode, and a bilingual mode. In the
monolingual mode, the primary language being used is most active, while the non-target
language is much less activated (but never completely “turned off”). In the intermediate mode,
the non-target language is more active than in the monolingual mode, but the target language
remains more active. And when in a bilingual mode, the non-target language is highly activate
(but less so than the target language) and both languages can be readily called upon to
accommodate code-switching or borrowings (see Yu & Schwieter, 2018 for more details).
Whereas code-switching refers to the practice of alternating between two or more languages
within a single conversation or discourse, borrowing involves the incorporation of words or
phrases from one language into another. Unlike code-switching, borrowing can occur over a
longer period and become integrated into the borrowing language’s lexicon. Although early views
of code-switching suggesting that it is a random and unsystematic phenomenon that was not
subject to formal syntactic constraints are now obsolete (MacSwan, 2009), research within the
universal grammar framework has largely been dedicated to exploring the systematic nature of
alternating between language systems. However, work conducted in this framework does not
attempt to address the motivation behind code-switching. According to Bhatia (2018), “the
challenge for linguistic research in the new millennium is to separate grammatical constraints
from those motivated by or triggered by socio-pragmatic factors/competence” (p. 17).
Finally, the expression of emotions, private thoughts, and autobiographical memory has been
argued to be best characterized in the native language, as demonstrated by quantitative and
qualitative differences between narration in the native language compared to a distant second
language (Dewaele, 2010; Martinovic & Altarriba, 2012; Pavlenko, 2005). It is important to note,
however, that bilinguals can keep their languages separate in certain situations, or integrate and
freely switch between them in other contexts (Myers-Scotton, 1998). Current views on the factors
that trigger code-switching concern a perceived change by the speaker in the socio-psychological
context of communicative events (Green, 2018).
3. The (Bilingual) Mental Lexicon
The mental lexicon, sometimes referred to as “the mental dictionary,” contains information
about words, such as their meanings, pronunciations, and grammatical characteristics. Above
and beyond this definition, the mental lexicon involves word activation, storage, processing, and
retrieval, making it a multifaceted framework. In fact, it is now believed that the mental lexicon
can be best characterized from a dynamic and integrated perspective (Libben & Goral, 2015). In
the case of bilingualism, Libben et al. (2017) argue that “adequate modeling of the (bilingual)
mental lexicon requires an understanding not only of dynamicity and integration as individual
constructs but also of the manner in which they interact with each other and with key phenomena

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in bilingual lexical processing” (p. 2). Indeed, many researchers now believe that a bilingual/
multilingual mental lexicon may be the default rather than the exception (Libben & Schwieter,
2019; Vaid & Meuter, 2017).
For monolingual individuals whose mental lexicon is already in place, an enduring area of
research has explored the mapping of new words in a second language to existing concepts and
the extent to which the two language systems are integrated or separate. Two accounts explaining
this process have been put forth. The first, known as the language-selective view, holds that the
two languages have independent mental lexicons that contain little to no interlingual interaction/
overlap (Scarborough et al., 1984). Under this assumption, the activation of one language does
not affect activation of features or words in the other language (Rodriguez-Fornells et al., 2002).
The second hypothesis, the nonselective account, argues that there is a single, integrated lexical-
conceptual system in which words and features in both languages are activated and selected in
parallel (Dijkstra & van Heuven, 2002; Spalek et al., 2014). In general, there is more support for
the nonselective than selective account, such that even when exclusively using one language, the
other language cannot be completely “turned off.”
In a well-cited study offering evidence for the nonselective account, Marian and Spivey (2003)
used eyetracking (described in Section 4) to explore the activation of a non-target language when
processing a target language. In their experiments, Russian-English bilinguals were presented
with four pictures of objects (e.g., a marker, stamp, fish, and lamp) and were asked to select the
object whose name was heard in English through headphones (e.g., “marker”). Critically, the
auditory stimuli had phonological overlap with one of the distractor objects’ Russian translation
(e.g., marka in Russian refers to a stamp). The results showed that participants looked more often
and longer at distractor pictures when their translation had phonological overlap with the
auditory stimulus. Moreover, these patterns emerged in both directions (i.e., when auditory
stimuli were presented in English or in Russian), suggesting that there is co-activation of words
in both languages, even when exclusively using one.
In the context of the nonselective account, several theoretical models have been put forth that
explain the processes involved in language production and recognition among bilinguals. Among
the most cited are the Revised Hierarchical Model (RHM; Kroll & Stewart, 1994) and the Bilingual
Interactive Activation (BIA+) Model (Dijkstra & van Heuven, 2002). The RHM is a developmental
model of the bilingual mental lexicon that assumes that there is differential strength of
association between a shared conceptual store for words in a highly proficient language (e.g., a
first language) and words in a less proficient language (e.g., a second language). For instance,
when asked to name a picture of a cat in the second language, a Hungarian first-language speaker
learning Hindi as a second language may need to initially associate the concept of a cat with the
Hungarian word that maps onto it before accessing the Hindi translation equivalent. In a study by
Clenton (2015), first-language speakers of Japanese, Mandarin, Cantonese, and Korean who were
learning English as a second language participated in a word-association task. The participants
were presented with a list of 30 stimulus words in English and were asked to produce up to four
associated words, also in English, for each stimulus. The analyses of their responses showed that
second-language processing via the first language correlated with participant’s second-language
proficiency: more proficient learners displayed less L1 mediation than less proficient learners.

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On a practical level, the RHM accounts for why less proficient language learners, when producing
language in a second language, appear to rely on word-to-word translations in their first
language. It appears as though the theoretical reason for this pattern is that words in the less
proficient language do not have a strong enough link to the concepts they represent compared to
words in the first language. Consequently, second-language words must first be associated with
their first-language equivalent in order to access their meaning. As proficiency increases in the
second language, the RHM argues that second-language lexical links to concepts strengthen and
can eventually be processed without consulting words in the first language.
The BIA+ Model, an updated version of the BIA Model (Dijkstra & van Heuven, 1998), is a
nonselective theoretical account of visual word recognition among bilinguals. The BIA+ argues
that bottom-up information (i.e., perceptual features) serves as a target-language cue that is
based on phonological and orthographic language-specific properties. In the model, two
functionally independent systems are proposed: an identification system containing
hierarchically ordered sublexical and lexical orthography that are mapped onto their
phonological realizations; and a task schema system which is responsible for overseeing
nonlinguistic information such as task difficulty and expectations. The task schema system is
argued to facilitate the activation of orthographical, phonological, and semantic representations,
along with a decision-parameter setting which best optimizes word recognition. Dijkstra et al.
(2019) offer the following example of how the BIA+ predicts the procedure involved in visual
processing the word “hood”:
In a Dutch-English bilingual, the activated COMPETITOR SET (or neighborhood) of HOOD
will include English words like FOOD, HOLD, and HOOT, and Dutch words like LOOD,
HOND, and HOOS. All these orthographic representations will then begin to activate their
meaning representations. Thus, the meaning of FOOD and HOND will be activated to
some extent in parallel with the meaning of the input word HOOD. At the same time,
active orthographic representations also directly activate their phonological
counterparts, so HOOD activates /hu:d/, FOOD activates /fu:d/, and so on. Semantically
active representations ‘spread’ their activation to other (associated or semantically
related) units. For instance, HOOD may spread activation to the meanings ‘HAT’ or ‘CAR’,
and FOOD to ‘HUNGRY’. (p. 658)
More recently, further updates have been made with respect to bilingual word recognition
through the Multilink Model (Dijkstra et al., 2019), a computational model that exploits the
presence of cross-language ambiguity. The Multilink Model can simulate both monolingual and
bilingual processing of words—for both production and comprehension—that vary in length,
cross-language similarity, and frequency of use. Moreover, the Multilink Model can simulate
processing patterns that both less proficient and highly proficient bilinguals display.

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4. Research Methods in Bilingualism
Significant strides have been made in diversifying the ways in which bilingual processing can be
explored through psycholinguistic and neurobiological methods (see Klassen & Schwieter,
forthcoming, for an overview). These measures allow researchers to collect and analyze
behavioral, electrophysiological, and neural imaging data, and make predictions about the
cognitive processes and neural bases of bilingual processing. Foundational to modern research
methods in psycholinguistics are behavioral measures that permit the analysis of offline data and
online judgments of language production and comprehension (Kroll et al., 2008). Online reaction
studies directly probe language processing in real time. For instance, in the lexical decision task,
participants are presented with strings of letters and are asked to indicate as quickly and
accurately as possible whether each string is a real word or a non-word by pressing a button. The
task permits researchers to measure lexical access and processing efficiency and offers valuable
information about how individuals access and recognize words in their language(s). In the
language-switching paradigm, participants are instructed to name pictures or words in one
language and then switch to another language as determined by a color cue (e.g., name pictures in
blue boxes in Language A, and pictures in red boxes in Language B). By measuring reaction times
and accuracy rates when a language switch is required, researchers can investigate the cognitive
processes involved in how bilinguals mentally control their languages. Other common
psycholinguistic measures include self-paced reading, grammaticality judgments, semantic
priming, among many others.
Offline methods are those which target offline responses or data, including target questionnaires
and corpora, and can be used to make inferences about language representation or processes.
Metalinguistic measures such as assessments of proficiency are often employed to complement
these methods, offering a more detailed profile of bilingual participants. For example, the
Language Experience and Proficiency Questionnaire (Marian et al., 2007) is a widely used
measure that elicits quantitative and descriptive information about bilinguals’ language
background, use, and proficiency. Returning to Cummins’s (1981) characterization of second-
language proficiency, researchers have developed standardized measures of CALP that assess
language abilities in decontextualized situations such as during completion of verbal analogies
(Woodcock & Munoz-Sandoval, 2001).
Eyetracking measures allow researchers to record precise eye movements and patterns, eliciting a
window into the processes engaged during reading text or examining pictures (Dussias, 2010).
Eyetracking uses sophisticated, highly sensitive cameras that contain a low-intensity infrared
light which illuminates participants’ eyes and records the reflection of their movements.
Typically, there are three behavioral patterns that are of interest to researchers employing
eyetracking. These include saccades, fixations, and regressions, as described by Schwieter (2021):

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As we read, our eyes do not smoothly progress across words equally in sentences. Instead,
they engage in saccades, or jolting-like eye movements that rapidly propel eye fixations
from one point to the next. It is believed that the speed of the saccade to the next fixation
point is so fast (usually occurring in 10–20 ms) that visual information is not processed
during the jump. The length of the saccade is usually 8–10 letters to the right where it will
take a brief pause of 200–250 ms. At this pause, or fixation point, two or three words will
be processed and then another saccade will occur. The length of the fixation is an index of
processing difficulty, with longer fixations implying more difficulty in processing.
Sometimes in difficult sentence structures such as in garden path sentences, a saccade
may regress in order to reread and reparse the sentence. These regressions are known as
regressive saccades. (p. 519)
Although early eyetracking devices were equipped with head-mounted cameras, modern versions
can be remote (e.g., an unobtrusive, naturalistic screen-based bar with no contact with the
participant) or mobile (e.g., built into glasses worn by the participant). These newer eyetracking
devices are more comfortable and less invasive than head-mounted versions. Using eyetracking,
therefore, presents the opportunity to examine subconscious processes and thus, more direct
questions can be asked and answered.
It is also possible to investigate bilingual processing by measuring the electric activity of the
brain. This approach can answer questions about physiological aspects of language in bilingual
processes, along with the neural mechanisms to which they correlate. Electroencephalography
(EEG) measures the brain’s electrical activity and changes in response to stimuli. These critical
stimuli, known as event-related potentials (ERPs), render highly sensitive temporal resolution as
a waveform and can be used to map the exact time course of language processing, from the
earliest stages in which there is no conscious awareness on the part of the participant, to overt
production or comprehension (Luck, 2005; Moreno et al., 2008). ERPs are detected by a net-like
cap containing several electrodes that are fitted on the scalp.
A typical pattern found in ERP studies examining syntactic and semantic processing is that there
is an increase in negative voltage around 400 ms after the presentation of a semantic violation.
For instance, in the sentence “The steaming coffee I drank was cold,” the brain would likely show
an increase in negativity about 400 ms after the word cold because it does not fit the semantic
expectations of steaming coffee. Compare the ERP elicited by the word cold in this semantically odd
sentence (as represented by the dotted line in Figure 1) with a version of the sentence that makes
more sense such as “The steaming coffee I drank was hot” (as shown by the solid line in Figure 1).
This typical pattern of semantic violation is known as the N400 effect. Studies in bilingualism
have revealed less consistent findings with respect to the N400 effect due to a variety of factors,
including language proficiency. For instance, a review by Jankowiak and Rataj (2017) reported
that although some studies underscore the
role of second language proficiency level in the N400 component by showing a delay in
the N400 peak latency only when participants were less proficient in their non-native
tongue, other researchers observed modulations in the N400 effect even when bilingual
speakers were highly proficient in L2. (p. 140)

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Figure 1. An ERP waveform for processing the words cold (dotted line) and hot (solid line) in the sentence “The
steaming coffee I drank was cold/hot.”
Although ERPs offer high temporal resolution, their disadvantage is that they do not provide
highly precise spatial resolution. Neuroimaging methods, on the other hand, have uncovered new
ways of measuring brain activity and the neural localization of language processes. One of the
earliest forms of brain imaging was the computerized tomography (CT) scan, which provides a
series of static X-ray images taken of the brain from different angles. However, more dynamic
measures examining language processing in the brain include Positron Emission Tomography
(PET) and Functional Magnetic Resonance Imaging (fMRI). Similar to EEG, these imaging
methods allow for participants/patients to partake in language tasks while brain activity is being
recorded in real time. Moreover, both PET and fMRI allow researchers to study the structural
changes in the brain. In PET, a participant is injected with harmless radioactive tracers called
positron-emitting isotopes. The isotopes are then traced in the blood, allowing the researcher to
detect areas of the brain involved in language processing at the molecular level (De Bleser et al.,
2003). fMRI is a minimally invasive method that relies on the magnetic field of the brain, and the
fact that blood contains iron, to track and measure blood flow (Bornkessel-Schlesewsky &
Friederici, 2007). The image that is produced by the fMRI is much more spatially accurate than
PET images, and can distinguish areas of neural activation that are a little as a millimeter apart.
Two other neural imaging techniques include diffusion tensor imaging (DTI), and functional
near-infrared spectroscopy (fNIRS). DTI enables researchers to observe the integrity of white-
matter and neuroplastic changes associated with bilingualism by tracking water molecules in
fiber tracks (Baum & Titone, 2014). Unlike other hemodynamic neuroimaging methods, DTI is
able to detect damaged brain areas in as little as 20 minutes after insult, whereas fMRI may reveal
brain damage up to 6 hours and CT scans may take up to 3–4 days. fNIRS is a type of fMRI, but the
physics of how it measures brain flow is distinct in that it relies on the absorption of near-

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infrared light (Arredondo et al., 2017). Although fNIRS is much less costly and more portable than
fMRI, given that data are collected through a cap placed on the surface of the scalp, its spatial
resolution is significantly lower than fMRI and is only able to measure about 10 mm into the
cortex.
5. Cognitive and Neural Effects of Bilingualism
Perhaps the most hotly debated issue in current research on bilingualism is whether there are
cognitive and neurological benefits incurred from knowing and using more than one language
(Bialystok, 2021a) and whether bilingualism can lead to cognitive reserve (Bialystok, 2021b).
These dialogues have been referred to as the bilingual advantage debate (for a review, see
Antoniou, 2019) and have had important implications for the understanding of how bilingualism
affects cognitive processes. While some studies demonstrate clear effects of how bilingualism
reshapes cognitive abilities and brain systems, others fail to observe such findings. Some
researchers have noted specific differences in methodological approaches (Paap et al., 2014) and
even publication biases (de Bruin & Della Salla, 2019; de Bruin et al., 2015) that obscure the
debate. Complicating the issue further is that “the bilingual experience is a change-inducing
event leading to speedy adaptations on different levels of processing, with brain changes at its
basis to accommodate for additional demands and specific requirements” (Schwieter & Festman,
2024, p. 157).
Over the last 15 years or so, a set of systematic reviews and meta-analyses have demonstrated the
inconclusiveness of the bilingual advantage debate. Although some of these publications have
reported cognitive and neural benefits of bilingualism (Adesope et al., 2010; Grundy, 2020;
Grundy & Timmer, 2016; Monnier et al., 2022; Tao et al., 2021; Van den Noort et al., 2019; Ware et
al., 2020), others have found little or no effects at all (Anderson et al., 2020; Degirmenci et al.,
2022; Donnelly et al., 2019; Filippi & Bright, 2023; Giovannoli et al., 2023; Gunnerud et al., 2020;
Lehtonen et al., 2018; Lowe et al., 2021; Samuel et al., 2018). The most recent review of some of
the challenges facing the bilingual advantage debate has been published in a book by Paap (2023).
Some scholars have suggested that researchers should end their quest for a bilingual advantage
(e.g., Paap et al., 2016). Others have argued that a deeper understanding is necessary (e.g., Dick et
al., 2019; Grundy, 2020; Poarch & Krott, 2019; Woumans & Duyck, 2015) or that a larger scope is
needed (Festman & Schwieter, 2019; Greve et al., 2021). In whichever direction the debate goes,
future studies must account for the findings that bilingualism may have positive consequences
for processing, performance on cognitive tasks, and on brain areas. Some of this body of work is
summarized in Table 1.

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•
•
•
•
•
•
•
•
Table 1. Findings Supporting Cognitive and Neurological Benefits of Bilingualism Compared to Monolingualism
Finding Possible Explanation Representative
Studies and
Reviews
Early bilinguals show greater sensitivity
to novelty, seek new information, and
demonstrate greater exploratory
behaviour.
The attentional system must be
adjusted to perceive and track
information in multiple languages
and to switch between two
languages.
Perceptual learning is refined to
discriminate between nuances across
languages.
D’Souza et al. (2020)
Filippi et al. (2020)
Bilingualism enhances extraction of
talker-specific information that is
encoded in speech signals.
Exposure to various speakers of
different languages.
Adjustment of language choice
according to communicative
situations.
Fecher & Johnson
(2019)
Nicoladis &
Smithson (2022)
Yu et al. (2021)
Bilingualism enhances metalinguistic
awareness and abstract thinking about
languages.
Input/use of two languages and
exposure to two cultures and scripts.
Bright et al. (2019)
Chin, &
Wigglesworth (2007)
Tran et al. (2019)
Bilingualism enhances adaptive
processes.
More languages place greater
processing demands on the control
system.
Festman (20l3)
Claussenius-Kalman
& Hernandez (2019)
Bilingualism benefits domain-general
control processes.
Parallel activation and constant
competition between two languages
for selection.
Bialystok (2018)
Kroll et al. (2015)
Bilingualism increases cognitive flexibility
in switching between tasks.
Multiple languages require more
mental flexibility.
Abutalebi & Green
(2007)
Barbu et al. (2020)
Poulin-Dubois et al.
(2022)

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•
•
•
•
•
•
•
•
Finding Possible Explanation Representative
Studies and
Reviews
Bilingualism enhances monitoring
abilities.
Greater need for control and
monitoring of two language systems
in single-language, dual-language,
and dense codeswitching contexts.
Czapka & Festman
(2021)
Green & Abutalebi
(2013)
Markiewicz et al.
(2022)
Bilingualism improves working memory
capacity and efficiency.
Regular experience of managing two
languages implies temporary
maintenance and constant updating
of information appropriate to the
content of language.
Antón et al. (2019)
Monnier et al. (2022)
Bilingualism delays clinical symptoms of
neurodegenerative diseases.
Continued exposure to and use of two
languages leads to greater cognitive
reserve.
Papageorgiou et al.
(2019)
Woumans et al.
(2015)
Bilingualism alters anatomical features in
specific brain areas, changes cortical
organization to enhance local processing,
and modifies connectivity between
specific regions to enhance processing.
Bilingual experience modifies aspects
of brain function and structure, and
affects grey matter density and white
matter integrity.
DeLuca et al. (2020)
Herholz & Zatorre
(2012)
Pfenninger et al.
(2023)
Bilingualism strengthens the domain-
general control network (i.e., lateral
prefrontal cortices and basal ganglia)
Networks for acquisition and
processing of languages overlap and
thus, strengthen.
Abutalebi & Green
(2007)
Luk et al. (2010)
Bilingualism improves conflict resolution. The anterior cingulate cortex and the
dorso-lateral prefrontal cortex may
receive ‘special tuning’ in order to
manage multiple language systems.
Del Maschio &
Abutalebi (2019)
With increases in proficiency of a less-
dominant language, bilingualism
dynamically restructures the brain.
Increased grey matter density in the
left inferior parietal region may be
correlated to proficiency.
Mechelli et al. (2004)
Pliatsikas et al.
(2020)
Bilinguals are better at flexibly selecting
and applying novel (mathematical) rules.
Increased activation in the basal
ganglia.
Grundy et al., 2020
Stocco & Prat, 2014

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•
Finding Possible Explanation Representative
Studies and
Reviews
Bilinguals display an enhanced state of
alertness.
The N1, P3, and LRP ERP components
are enhanced when bilinguals are
surrounded by words from two
languages.
Timmer, Costa. et
al. 2021
Timmer,
Wodniecka, et al.
2021
Moreover, subsequent work should address the possibilities that bilinguals: (a) may be inherently
wired for higher levels of cognitive functions; or (b) may acquire higher levels of such functions
as a consequence of bilingualism. Festman (2021) argues that a two-sided approach in
determining whether or both possibilities are at play:
An individual may start off genetically well-equipped in terms of cognitive control abilities,
memory capacity, auditory cortex, and eagerness to learn and thus develop greater
multilingual skills.
or
An individual could be born into a bi- or multilingual family and acquire two or more
languages from early on, which may consequently lead to enhanced cognitive skills due to
extensive exposure or training in two or more languages.
Recent studies have shown genetic modulation of the relationship between bilingual adaptation
in executive function, decision-making, and language control (Liu et al., 2023a, 2023b). Based on
the current evidence related to these complex issues, the “interplay between genetics, language
use, and communicative demands, as well as general environmental factors, yet awaits our
understanding in general—and of its development in particular” (Festman, 2021, p. 25).
6. Moving Forward
For bilinguals, language systems are continuously active and adapting to communicative
demands of the environment around them. Libben et al. (2017) argue that “adequate modeling of
the (bilingual) mental lexicon requires an understanding not only of dynamicity and integration
as individual constructs but also of the manner in which they interact with each other and with
key phenomena in bilingual lexical processing” (p. 2). Abandoning a representational approach in
favor of a dynamic, activity-based view has both theoretical and experimental advantages
(Libben, 2022). Moreover, it may be beneficial to entertain the notion that the bilingual brain and
the cognitive capacity to acquire multiple languages may be the default rather than the exception
(Libben & Schwieter, 2019; Vaid & Meuter, 2017).

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With respect to experimental methods, particularly neuroimaging, significant strides have been
made to uncover the cognitive and neural underpinnings of bilingualism. Although studies
employing these methods have opened a new chapter in our understanding of the bilingual brain,
such understanding is subject to the application and limitations of the methods available (Bhatia,
2018; Vaid, 2018). For instance, fNIRS studies examining bilingualism (e.g., Hull et al., 2009;
Quaresima et al., 2002) are relatively few and far between. Moreover, hemodynamic
neuroimaging studies exploring share or separated language localization have not reached a
consensus, with some work ranging from finding bilateral hemispheric involvement in early
bilinguals and greater left hemispheric involvement in late bilinguals to no lateralization
differences between bilinguals and monolinguals. Playing a significant role in these discrepancies
are the relative power of techniques, diverse backgrounds of bilinguals, linguistic tasks tested,
and the differential use of declarative memory (Paradis, 2004).
Finally, given the complexity of the factors examined in the contentious bilingual advantage
debate, future work should attempt to reduce the variability of the reported effects through more
stringent sampling methods and by employing sensitive tests that can more accurately detect
subtle differences. Although it may be unlikely that a single factor is able to explain disparate
findings with respect to a bilingual advantage (Baum & Titone, 2014), it may be the case that not
all cognitive advantages are extended to every bilingual under all circumstances. According to
Antoniou (2019), a goal of future research in this area should be to identify the critical variables of
bilingual experience that may account for the reported processing differences between
monolinguals and bilinguals. In Green and Abutalebi’s (2013) adaptive control hypothesis, the
variable range of bilingual types is elaborated, demonstrating that not all bilinguals are the same
in terms of their language use and background. The model provides fertile ground for future work
to untangle confounding and differential effects. Hypotheses could be further bolstered through
the development of ambitious and rigorous research methods that pay close attention to task
differences and could more accurately predict which bilingual experiences are more likely to lead
to cognitive benefits.
Further Reading
There is a significant amount of published work on language processing and bilingualism, many of which offer
handbook-length, compelling synergies between research fields. This section lists some of these useful resources that
offer excellent dialogues on the state of the art.
Altarriba, J., & Heredia, R. (2018). Introduction to bilingualism: Principles and processes (2nd ed.). Routledge.
Bhatia, T., & Ritchie, W. (Eds.). (2012). The handbook of bilingualism and multilingualism (2nd ed.). Wiley-Blackwell.
Costa, A., & , Schwieter J. W. (Trans.). (2019). The bilingual brain: And what it tells us about the science of language.
Penguin Random House.
Dabrowska, E., & Divjak, D. (2015). The handbook of cognitive linguistics. De Gruyter Mouton.
Dancygier, B. (2017). The Cambridge handbook of cognitive linguistics. Cambridge University Press.

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de Groot, A. (2011). Language and cognition in bilinguals and multilinguals: An introduction. Psychology Press.
de Groot, A., & Kroll, J. (Eds.). (1997). Tutorials in bilingualism: Psycholinguistic perspectives. Erlbaum.
De Houwer, A., & Ortega, L. (Eds.). (2018). The Cambridge handbook of bilingualism. Cambridge University Press.
Fernández, E., & Smith Cairns, H. (Eds.). (2017). The handbook of psycholinguistics. Wiley-Blackwell.
Filipović, L., & Pütz, M. (Eds.). (2014). Multilingual cognition and language use: Processing and typological perspectives.
Benjamins.
Geeraerts, D., & Cuyckens, H. (Eds.). (2010). The Oxford handbook of cognitive linguistics. Oxford University Press.
Grosjean, F., & Li, P. (2013). The psycholinguistics of bilingualism. Wiley-Blackwell.
Hernández, A. (2013). The bilingual brain. Oxford University Press.
Herschensohn, J. (2022). Bilingualism, language development, and processing across the lifespan. Benjamins.
Kroll, J., & de Groot, A. (Eds.). (2005). The handbook of bilingualism: Psycholinguistic approaches. Oxford University
Press.
Pavlenko, A. (2014). The bilingual mind: And what it tells us about language and thought. Cambridge University Press.
Schwieter, J. W. (Ed.). (2014). Cognitive control and consequences of multilingualism. Benjamins.
Schwieter, J. W. (Ed.). (2015). The Cambridge handbook of bilingual processing. Cambridge University Press.
Schwieter, J. W. (Ed.). (2019). The handbook of the neuroscience of multilingualism. Wiley-Blackwell.
Schwieter, J. W., & Benati, A. (Eds.). (2019). The Cambridge handbook of language learning. Cambridge University
Press.
Spivey, M., McRae, K., & Joanisse, M. (Eds.). (2012). The Cambridge handbook of psycholinguistics. Cambridge
University Press.
Traxler, M., & Gernsbacher, M. (Eds.). (2006). The handbook of psycholinguistics. Elsevier.
Vaid, J. (Ed.). (2016). Language processing in bilinguals: Psycholinguistic and neuropsychological perspectives.
Routledge.
Wei, L. (Ed.). (2007). The bilingualism reader (2nd ed.). Routledge.
Xu, W., & Taylor, J. (2021). The Routledge handbook of cognitive linguistics. Routledge.
References
Abutalebi, J., & Green, D. (2007). Bilingual language production: The neurocognition of language representation and
control. Journal of Neurolinguistics, 20, 242–275.

Bilingual Language Processing
Page 16 of 23
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Adesope, O., Lavin, T., Thompson, T., & Ungerleider, C. (2010). A systematic review and meta-analysis of the cognitive
correlates of bilingualism. Review of Educational Research, 80(2), 207–245.
Anderson, J. A. E., Hawrylewicz, K., & Grundy, J. G. (2020). Does bilingualism protect against dementia? A meta-
analysis. Psychonomic Bulletin & Review, 27(5), 952–965.
Antón, E., Carreiras, M., & Duñabeitia, J. A. (2019). The impact of bilingualism on executive functions and working
memory in young adults. PLoS ONE, 14(2), e0206770.
Antoniou, M. (2019). The advantages of bilingualism debate. Annual Review of Linguistics, 5, 395–415.
Arredondo, M., Hu, X.-S., Satterfield, T., & Kovelman, I. (2017). Bilingualism alters children’s frontal lobe functioning for
attentional control. Developmental Science, 20(3), e12377.
Austin, L., Hernandez, A., & Schwieter, J. W. (2019). Proficiency predictors in sequential bilinguals. Cambridge University
Press.
Barbu, C. A., Gillet, S., & Poncelet, M. (2020). Investigating the effects of language-switching frequency on attentional
and executive functioning in proficient bilinguals. Frontiers in Psychology, 11, 1078.
Baum, S., & Titone, D. (2014). Moving toward a neuroplasticity view of bilingualism, executive control, and aging.
Applied Psycholinguistics, 35(5), 857–894.
Bhatia, T. (2018). Bilingualism and multilingualism. In M. Arnoff (Ed.), Oxford bibliographies in linguistics (pp. 1–28).
Oxford University Press.
Bialystok, E. (2018). Bilingualism and executive function: What’s the connection? In D. Miller, F. Bayram, J. Rothman, &
L. Serratrice (Eds.), Bilingual cognition and language: The state of the science across its subfields (pp. 283–305). John
Benjamins.
Bialystok, E. (2021a). Bilingualism as a slice of Swiss cheese. Frontiers in Psychology, 12, 769323.
Bialystok, E. (2021b). Bilingualism: Pathway to cognitive reserve. Trends in Cognitive Science, 25, 355–364.
Bornkessel-Schlesewsky, I., & Friederici, A. (2007). Neuroimaging studies of sentence and discourse comprehension. In
M. Gaskell (Ed.), The Oxford handbook of psycholinguistics. Oxford University Press.
Bright, P., Ouzia, J., & Filippi, R. (2019). Multilingualism and metacognitive processing. In J. Schwieter (Ed.), The
handbook of the neuroscience of multilingualism (pp. 355–371). Wiley-Blackwell.
Chin, N. B., & Wigglesworth, G. (2007). Bilingualism: An advanced resource book. Routledge.
Chomsky, N. (1986). Knowledge of language: Its nature, origin, and use. Praeger.
Claussenius-Kalman, H. L., & Hernandez, A. E. (2019). Neurocognitive effects of multilingualism throughout the
lifespan: A developmental perspective. In J. W. Schwieter & M. Paradis (Eds.), The handbook of the neuroscience of
multilingualism (pp. 655–684).
Clenton, J. (2015). Testing the revised hierarchical model: Evidence from word associations. Bilingualism: Language
and Cognition, 18(1), 118–125.

Bilingual Language Processing
Page 17 of 23
Printed from Oxford Research Encyclopedias, Linguistics. Under the terms of the licence agreement, an individual user may print out
a single article for personal use (for details see Privacy Policy and Legal Notice).
Subscriber: OUP-Reference Gratis Access; date: 25 August 2024
Cummins, J. (1981). The role of primary language development in promoting educational success for language
minority students. In California State Department of Education (Ed.), Schooling and language minority students: A
theoretical rationale (pp. 3–49). California State University.
Czapka, S., & Festman, J. (2021). Wisconsin card sorting test reveals a monitoring advantage but not a switching
advantage in multilingual children. Journal of Experimental Child Psychology, 204, 105038.
D’Souza, D., Brady, D., Haensel, J. X., & D’Souza, H. (2020). Is mere exposure enough? The effects of bilingual
environments on infant cognitive development. Royal Society Open Science, 7, 180–191.
De Bleser, R., Dupont, P., Postler, J., Bormans, G., Speelman, D., Mortelmans, L., & Debrock, M. (2003). The
organization of the bilingual lexicon: A PET study. Journal of Neurolinguistics, 16(4–5), 439–456.
de Bot, K. (2019). Defining and assessing multilingualism. In J. W. Schwieter (Ed.), The neuroscience of bilingualism (pp.
1–18). Wiley.
de Bruin, A., & Della Salla, S. (2019). The bilingual advantage debate: Publication biases and the decline effect. In J. W.
Schwieter (Ed.), The handbook of the neuroscience of multilingualism (pp. 736–753). Wiley-Blackwell.
de Bruin, A., Treccani, B., & Della Sala, S. (2015). Cognitive advantage in bilingualism: An example of publication bias?
Psychological Science, 26(1), 99–107.
Degirmenci, M. G., Grossmann, J. A., Meyer, P., & Teichmann, B. (2022). The role of bilingualism in executive functions
in healthy older adults: A systematic review. International Journal of Bilingualism, 26(4), 426–449.
Del Maschio, N., & Abutalebi, J. (2019). Language organization in the bilingual and multilingual brain. In J. Schwieter
(Ed.), The handbook of the neuroscience of multilingualism (pp. 197–213). Wiley.
DeLuca, V., Segaert, K., Mazaheri, A., & Krott, A. (2020). Understanding bilingual brain function and structure changes?
U bet! A unified bilingual experience trajectory model. Journal of Neurolinguistics, 56, 100930.
Dewaele, J.-M. (2010). Emotions in multiple languages. Palgrave Macmillan.
Dick, A. S., Garcia, N. L., Pruden, S. M., Thompson, W. K., Hawes, S. W., Sutherland, M. T., Riedel, M., Laird, A., &
Gonzalez, R. (2019). No evidence for a bilingual executive function advantage in the ABCD study. Nature Human
Behaviour, 3(7), 692–701.
Dijkstra, A., & van Heuven, W. (1998). The BIA model and bilingual word recognition. In J. Grainger & A. Jacobs (Eds.),
Localist connectionist approaches to human cognition (pp. 189–225). Erlbaum.
Dijkstra, T., & van Heuven, W. (2002). The architecture of the bilingual word recognition system: From identification to
decision. Bilingualism: Language and Cognition, 5, 175–197.
Dijkstra, T., Wahl, A., Buytenhuijs, F., Van Halem, N., Al-Jibouri, Z., De Korte, M., & Rekké, S. (2019). Multilink: A
computational model for bilingual word recognition and word translation. Bilingualism: Language and Cognition,
22(4), 657–679.
Donnelly, S., Brooks, P., & Homer, B. (2019). Is there a bilingual advantage on interference-control tasks? A multiverse
meta-analysis of global reaction time and interference cost. Psychonomic Bulletin & Review, 26, 1122–1147.

Bilingual Language Processing
Page 18 of 23
Printed from Oxford Research Encyclopedias, Linguistics. Under the terms of the licence agreement, an individual user may print out
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Subscriber: OUP-Reference Gratis Access; date: 25 August 2024
Dussias, P. (2010). Uses of eye-tracking data in second language sentence processing research. Annual Review of
Applied Linguistics, 30, 149–166.
Eberhard, D., Simons, G., & Fennig, C. (Eds.). (2023). Ethnologue: Languages of the world (26th ed.). SIL International.
Fecher, N., & Johnson, E. K. (2019). Bilingual infants excel at foreign‐language talker recognition. Developmental
Science, 22(4), e12778
Festman, J. (2013). The complexity-cost factor in bilingualism. Behavioral and Brain Sciences, 36(4), 355.
Festman, J. (2021). Learning and processing multiple languages: The more the easier? Language Learning, 71(S1), 121–
162.
Festman, J., & Schwieter, J. W. (2019). Self-concepts in reading and spelling among mono-and multilingual children:
Extending the bilingual advantage. Behavioral Sciences, 9(4), 39.
Filippi, R., & Bright, P. (2023). A cross-sectional developmental approach to bilingualism: Exploring neurocognitive
effects across the lifespan. Ampersand, 10, 100097.
Filippi, R., Ceccolini, A., Periche-Tomas, E., Papageorgiou, A., & Bright, P. (2020). Developmental trajectories of control
of verbal and non-verbal interference in speech comprehension in monolingual and multilingual children. Cognition,
200, 104252.
Giovannoli, J., Martella, D., & Casagrande, M. (2023). Executive functioning during verbal fluency tasks in bilinguals: A
systematic review. International Journal of Language & Communication Disorders, 58(4), 1316–1334.
Green, D. (2018). Language control and code-switching. Languages, 3(2), 8.
Green, D., & Abutalebi, J. (2013). Language control in bilinguals: The adaptive control hypothesis. Journal of Cognitive
Psychology, 25(5), 515–530.
Greve, W., Koch, M., Rasche, V., & Kersten, K. (2021). Extending the scope of the “cognitive advantage” hypothesis:
Multilingual individuals show higher flexibility of goal adjustment. Journal of Multilingual and Multicultural
Development, 45(4), 822–838.
Grosjean, F. (1989). Neurolinguists, beware! The bilingual is not two monolinguals in one person. Brain and Language,
36(1), 3–15.
Grosjean, F. (1998). Studying bilinguals: Methodological and conceptual issues. Bilingualism: Language and Cognition,
1, 131–149.
Grosjean, F. (2001). The bilingual’s language modes. In J. Nicol (Ed.), One mind, two languages: Bilingual language
processing (pp. 1–22). Blackwell.
Grosjean, F. (2010). Bilingual: Life and reality. Harvard University Press.
Grundy, J. G. (2020). The effects of bilingualism on executive functions: An updated quantitative analysis. Journal of
Cultural Cognitive Science, 4(2), 177–199.

Bilingual Language Processing
Page 19 of 23
Printed from Oxford Research Encyclopedias, Linguistics. Under the terms of the licence agreement, an individual user may print out
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Subscriber: OUP-Reference Gratis Access; date: 25 August 2024
Grundy, J. G., Pavlenko, E., & Bialystok, E. (2020). Bilingualism modifies disengagement of attention networks across
the scalp: A multivariate ERP investigation of the IOR paradigm. Journal of Neurolinguistics, 56, 100933.
Grundy, J., & Timmer, K. (2016). Bilingualism and working memory capacity: A comprehensive meta-analysis. Second
Language Research, 3, 325–340.
Gunnerud, H., ten Braak, D., Reikerås, E., Donolato, E., & Melby-Lervåg, M. (2020). Is bilingualism related to a cognitive
advantage in children? A systematic review and meta-analysis. Psychological Bulletin, 146(12), 1059–1083.
Hakuta, K. (1986). Mirror of language. Basic Books.
Haugen, E. (1953). The Norwegian language in America: A study in bilingual behavior. University of Pennsylvania Press.
Herholz, S., & Zatorre, R. (2012). Musical training as a framework for brain plasticity: Behavior, function, and structure.
Neuron, 76(3), 486–502.
Hull, R., Bortfeld, H., & Koons, S. (2009). Near-infrared spectroscopy and cortical responses to speech production. The
Open Neuroimaging Journal, 3, 26–30.
Jakobson, R., Lévi-Straus, C., Voegelia, L., & Seboek, T. (1953). Results of the conference of anthropologists and
linguists. International Journal of American Linguistics, 19(2), 1–67.
Jankowiak, K., & Rataj, K. (2017). The N400 as a window into lexico-semantic processing in bilingualism. Poznań
Studies in Contemporary Linguistics, 53(1), 119–156.
Kantor, J. (1936). An objective psychology of grammar. Indiana University Press.
Klassen, G., & Schwieter, J. W. (Eds.). (Forthcoming). Quantitative research methods in multilingual acquisition and
processing. Benjamins.
Kroll, J., & Stewart, E. (1994). Category interference in translation and picture naming: Evidence for asymmetric
connections between bilingual memory representations. Journal of Memory and Language, 33, 149–174.
Kroll, J., Gerfen, C., & Dussias, P. (2008). Laboratory designs and paradigms in psycholinguistics. In L. Wei & M. Moyer
(Eds.), The Blackwell guide to research methods in bilingualism and multilingualism (pp. 108–131). Blackwell.
Kroll, J., Dussias, P. E., Bice, K., & Perrotti, L. (2015). Bilingualism, mind, and brain. Annual Review of Linguistics, 1, 377.
Lehtonen, M., Soveri, A., Laine, A., Järvenpää, J., & de Bruin, A. (2018). Is bilingualism associated with enhanced
executive functioning in adults? A meta-analytic review. Psychological Bulletin, 144(4), 394–425.
Libben, G. (2022). Lexical representations in language processing. In M. Arnoff (Ed.), Oxford bibliographies in linguistics
(pp. 1–19). Oxford University Press.
Libben, G., & Goral, M. (2015). How bilingualism shapes the mental lexicon. In J. W. Schwieter (Ed.), The Cambridge
handbook of bilingual processing (pp. 631–644). Cambridge University Press.
Libben, G., & Schwieter, J. W. (2019). Lexical organization and reorganization in the multilingual mind. In J. Schwieter
(Ed.), The handbook of the neuroscience of multilingualism (pp. 297–312). Wiley-Blackwell.

Bilingual Language Processing
Page 20 of 23
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Libben, M., Goral, M., & Libben, G. (2017). The dynamic lexicon: Complex words in bilingual minds. In M. Libben, M.
Goral, & G. Libben (Eds.), Bilingualism: A framework for understanding the mental lexicon (pp. 1–7). Benjamins.
Liu, D., Mu, L., Schwieter, J. W., & Liu, H. (2023a). The COMT gene modulates the relationship between bilingual
adaptation in executive function and decision-making: An EEG study. Cognitive Neurodynamics, 17, 893–907.
Liu, D., Xing, Z., Huang, J., Schwieter, J. W., & Liu, H. (2023b). Genetic bases of language control in bilinguals: Evidence
from an EEG study. Human Brain Mapping, 44(9), 3624–3643.
Lowe, C., Cho, I., Goldsmith, S., & Morton, B. (2021). The bilingual advantage in children’s executive functioning is not
related to language status: A meta-analytic review. Psychological Science, 32(7), 1115–1146.
Luck, S. (2005). An introduction to the event-related potential technique. MIT Press.
Luk, G., Anderson, J. A., Craik, F. I., Grady, C., & Bialystok, E. (2010). Distinct neural correlates for two types of inhibition
in bilinguals: Response inhibition versus interference suppression. Brain and Cognition, 74(3), 347–357.
Lust, B. (2011). Acquisition of language. In P. Hogan (Ed.), The Cambridge encyclopaedia of the language sciences (pp.
56–64). Cambridge University Press.
Mackey, W. (1967). Bilingualism as a world problem. Harvest House.
MacSwan, J. (2009). Generative approaches to codeswitching. In B. Bullock & A. Toribio (Eds.), The Cambridge
handbook of linguistic code-switching (pp. 336–357). Cambridge University Press.
Marian, V., Blumenfeld, H., & Kaushanskaya, M. (2007). The language experience and proficiency questionnaire (LEAP-
Q): Assessing language profiles in bilinguals and multilinguals. Journal of Speech, Language, and Hearing Research, 50,
940–967.
Marian, V., & Spivey, M. (2003). Competing activation in bilingual language processing: Within- and between-language
competition. Bilingualism: Language and Cognition, 6, 97–115.
Markiewicz, R., Mazaheri, A., & Krott, A. (2022). Bilingualism can cause enhanced monitoring and occasional delayed
responses in a Flanker task. European Journal of Neuroscience.
Martinovic, I., & Altarriba, A. (2012). Bilingualism and emotions: Implications for mental health. In T. Bhatia & W.
Ritchie (Eds.), The handbook of bilingualism and multilingualism (2nd ed., pp. 292–320). Wiley-Blackwell.
Mechelli, A., Crinion, J. T., Noppeney, U., O’Doherty, J., Ashburner, J., Frackowiak, R. S., & Price, C. J. (2004).
Neurolinguistics: Structural plasticity in the bilingual brain. Nature, 431(7010), 757.
Monnier, C., Boiché, J., Armandon, P., Baudoin, S., & Bellocchi, S. (2022). Is bilingualism associated with better working
memory capacity? A meta-analysis. International Journal of Bilingual Education and Bilingualism, 25(6), 2229–2255.
Moreno, E., Rodríguez-Fornells, A., & Laine, M. (2008). Event-related potentials (ERPs) in the study of bilingual
language processing. Journal of Neurolinguistics, 21(6), 477–508.
Myers-Scotton, C. (1998). Codes and consequences: Choosing linguistic varieties. Oxford University Press.

Bilingual Language Processing
Page 21 of 23
Printed from Oxford Research Encyclopedias, Linguistics. Under the terms of the licence agreement, an individual user may print out
a single article for personal use (for details see Privacy Policy and Legal Notice).
Subscriber: OUP-Reference Gratis Access; date: 25 August 2024
Nicoladis, E., & Smithson, L. (2022). Gesture in bilingual language acquisition. In A. Morgenstern & S. Goldin-Meadow
(Eds.), Gesture in language: Development across the lifespan (pp. 297–315). De Gruyter Mouton.
Paap, K. (2023). The bilingual advantage in executive functioning hypothesis: How the debate provides insight into
psychology’s replication crisis. Routledge.
Paap, K., Johnson, H., & Sawi, O. (2014). Are bilingual advantages dependent upon specific tasks or specific bilingual
experiences? Journal of Cognitive Psychology, 26(6), 615–639.
Paap, K. R., Johnson, H. A., & Sawi, O. (2016). Should the search for bilingual advantages in executive functioning
continue. Cortex, 74(4), 305–314.
Papageorgiou, A., Bright, P., Periche Tomas, E., & Filippi, R. (2019). Evidence against a cognitive advantage in the older
bilingual population. Quarterly Journal of Experimental Psychology, 72(6), 1354–1363.
Paradis, M. (2004). A neurolinguistic theory of bilingualism. Benjamins.
Pavlenko, A. (2005). Emotions and bilingualism. Cambridge University Press.
Peal, E., & Lambert, W. (1962). Relation of bilingualism to intelligence. Psychological Monographs, 76(27), 1–23.
Pfenninger, S., Festman, J., & Singleton, D. (2023). Second language acquisition and lifelong learning: An introduction
and methodological guide. Routledge.
Pliatsikas, C., Meteyard, L., Veríssimo, J., DeLuca, V., & Shattuck, K. (2020). The effect of bilingualism on brain
development from early childhood to young adulthood. Brain Structure and Function, 225, 2131 ߝ2152 .
Poarch, G. J., & Krott, A. (2019). A bilingual advantage? An appeal for a change in perspective and recommendations
for future research. Behavioral Sciences, 9(9), 95.
Poulin-Dubois, D., Neumann, C., Masoud, S., & Gazith, A. (2022). Effect of bilingualism on infants’ cognitive flexibility.
Bilingualism: Language and Cognition, 25(3), 484–497.
Pronko, N. (1946). Language and psycholinguistics: A review. Psychological Bulletin, 43, 189–239.
Quaresima, V., Ferari, M., van der Sluijs, M., Menssen, J., & Colier, W. (2002). Lateral frontal cortex oxygenation changes
during translation and language switching revealed by non-invasive near-infrared multiple-point measurements.
Brain Research Bulletin, 59(3), 235–243.
Rodriguez-Fornells, A., Rotte, M., Heinze, H., Nösselt, T., & Münte, T. (2002). Brain potential and functional MRI
evidence for how to handle two languages with one brain. Nature, 415(6875), 1026–1029.
Samuel, S., Roehr-Brackin, K., Pak, H., & Kim, H. (2018). Cultural effects rather than a bilingual advantage in cognition:
A review and an empirical study. Cognitive Science, 42, 2313–2341.
Scarborough, D., Gerard, L., & Cortese, C. (1984). Independence of lexical access in bilingual word recognition. Journal
of Verbal Learning and Verbal Behavior, 23(1), 84–99.
Schwieter, J. W. (2021). Psycholinguistics: Language processing. In J. Bruhn de Garavito & J. W. Schwieter (Eds.),
Introducing linguistics (pp. 501–534). Cambridge University Press.

Bilingual Language Processing
Page 22 of 23
Printed from Oxford Research Encyclopedias, Linguistics. Under the terms of the licence agreement, an individual user may print out
a single article for personal use (for details see Privacy Policy and Legal Notice).
Subscriber: OUP-Reference Gratis Access; date: 25 August 2024
Schwieter, J. W., & Festman, J. (2024). The cognitive neuroscience of bilingualism. Cambridge University Press.
Spalek, K., Hoshino, N., Wu, Y., Damian, M., & Thierry, G. (2014). Speaking two languages at once: Unconscious native
word form access in second language production. Cognition, 133(1), 226–231.
Stocco, A., & Prat, C. S. (2014). Bilingualism trains specific brain circuits involved in flexible rule selection and
application. Brain and Language, 137, 50–61.
Tao, L., Wang, G., Zhu, M., & Cai, Q. (2021). Bilingualism and domain-general cognitive functions from a neural
perspective: A systematic review. Neuroscience & Biobehavioral Reviews, 125, 264–295.
Timmer, K., Costa, A., & Wodniecka, Z. (2021). The source of attention modulations in bilingual language contexts.
Brain and Language, 223, 105040.
Timmer, K., Wodniecka, Z., & Costa, A. (2021). Rapid attentional adaptations due to language (monolingual vs
bilingual) context. Neuropsychologia, 159, 107946.
Tran, C. D., Arredondo, M. M., & Yoshida, H. (2019). Early executive function: The influence of culture and bilingualism.
Bilingualism: Language and Cognition, 22(4), 714–732.
Umbel, V., & Oller, D. (1994). Developmental changes in receptive vocabulary in Hispanic bilingual school children.
Language Learning, 44(2), 221–242.
Vaid, J. (2018). The bilingual brain revised: What is right and what is left? In J. Altarriba & R. Heredia (Eds.), An
introduction to bilingualism: Principles and processes (pp. 139–155). Erlbaum.
Vaid, J., & Meuter, R. (2017). Languages without borders: Reframing the study of the bilingual mental lexicon. In M.
Libben, M. Goral, & G. Libben (Eds.), Bilingualism: A framework for understanding the mental lexicon (pp. 8–39).
Benjamins.
Van den Noort, M., Struys, E., Bosch, P., Jaswetz, L., Perriard, B., Yeo, S., Barish, P., Vermeire, K., Lee, S., & Lim, S.
(2019). Does the bilingual advantage in cognitive control exist and if so, what are the modulating factors: A systematic
review. Behavioral Sciences, 9, 27.
Ware, A., Kirkovski, M., & Lum, J. (2020). Meta-analysis reveals a bilingual advantage that is dependent on task and
age. Frontiers in Psychology, 11, 1458.
Weinreich, U. (1953). Languages in contact: Findings and problems. De Gruyter Mouton.
Woodcock, R., & Munoz-Sandoval, A. (2001). Woodcock-Munoz language survey: Normative update. Riverside.
Woumans, E., & Duyck, W. (2015). The bilingual advantage debate: Moving toward different methods for verifying its
existence. Cortex, 73, 356–357.
Woumans, E. V. Y., Santens, P., Sieben, A., Versijpt, J. A. N., Stevens, M., & Duyck, W. (2015). Bilingualism delays clinical
manifestation of Alzheimer’s disease. Bilingualism: Language and Cognition, 18(3), 568–574.
Yu, C. L., Kovelman, I., & Wellman, H. M. (2021). How bilingualism informs theory of mind development. Child
Development Perspectives, 15(3), 154–159.

Bilingual Language Processing
Page 23 of 23
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a single article for personal use (for details see Privacy Policy and Legal Notice).
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Yu, Z., & Schwieter, J. W. (2018). Recognizing the effects of language mode on the cognitive advance of bilingualism.
Frontiers in Psychology, 9(366), 1–6.
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