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2.2 Language Switching and Mixing: a Cognitive Neuroscience Perspective

2.2.2 Language Mixing

Language mixing was defined as the use of two languages within one sentence in conversations (Bokamba, 1989). Perecman (1984, 1989) provided one of the earliest detailed analysis and classification of various types of pathological mixing phenomena in aphasic multilingual patients which are listed in Table 1 below.

Table 1: Types of Pathological Mixing Phenomena

Types Examples Explanations

Word mixing “…to think for my boys from England you know und hab ich immer so gemacht und one day I said to the boy” (…to think for my boys from England you know and I have always done this way and one day I said to the boy)

When they cannot find a word owing to anomia, bilingual aphasics are likely to substitute it with a corresponding word in another language. In this case, patients are usually aware of the mixing phenomenon. Sometimes they unconsciously mix words from different languages within a sentence.

Root and suffix mixing

Per andre all’ospedale ho preso la carra [to go to the hospital I took the carra] (from the English

“car” plus the Italian suffix “a”)

Patient would utter words in an English root and added the Italian suffix

Blending of syllables

The translation of the English butterfly into French la vontre fly

Syllables were blended from

Instead of reading the English sentence: “I got home from work”, a patient said: “I will home coming,” which is syntactically wrong, because it uses the German syntax where the verb takes the final position.

English vocabulary with German

A patient pronounced the English word door like the French word dur.; heard (English) was produces as hund (German)

Utterance of a word in one language but pronouncing the

Examiner: “What was your job in Canada?”

Patient: “I was working with ce faccio coi…”(English-Italian alternation)

The tendency to answer in a language different from that spoken by the interlocutor is to be considered a mixing

phenomenon.

The above types of pathological mixing were analyzed from different linguistic levels (phonological, morphological, lexical-semantic and syntactic). Perecman (1989) suggested that the poorly delineated language boundaries in polyglot aphasic’s mental grammar and the phenomena in language mixing and spontaneous translation were pathological conditions commonly found in bilingual aphasics. However, Grosjean (1985) denied this proposal and suggested that the language mixing is not an abnormal behavior in bilingual aphasics; rather, he viewed the mixing of languages as a communicative strategy to construct an effective

conversation with others. Furthermore, studies have shown that morphological and lexical semantic level mixing are a common occurrence in normal bilinguals (Matras, 2000; Bhat &

Chengappa, 2003; Bhat & Shyamala, 2005).

Fabbro (1999) proposed three rules that normal multilingual individuals would have to adhere to in order to produce acceptable and appropriate mixed sentences.

1. In a sentence the subject (if it is a pronoun) and the predicate (verb) generally belong to the same language.

2. Hardly ever are prepositions alone expressed in a language other than the one used for the whole sentence.

3. In mixing, there is a clear tendency to express function words or proverbs in the mother tongue.

Normal bilinguals or multilinguals respect the rules of mixing in order to have a constructive conversation with others; however, if an individual violates the above rules of language mixing and is unable to make an effective conversation with others, the situation is likely to be treated as a pathological condition. Numerous case studies on brain-damaged patients have reported that pathological mixing is mainly due to the lesion in the left postrolandic area (Fabbro, 1999 & 2001a), which was also commonly found to be associated with Wernicke’s aphasia, (Fabbro, 1999; Fabbro et al., 2000).

It is also worth reviewing Muysken (2000) typology, who classified code-mixing into 3

distinct processes:

a. Insertion. The incorporation of lexical items or entire constituents into a structure of another language;

b. Alternation. The process of alternation occurred between different structures of languages within the same conversation.

c. Congruent Lexicalization. The convergence of both languages’ grammatical and lexical structures to form a new utterances.

The definition of insertional process is best fit to describe the language mixing sentences of the current study where the lexical items (nouns) are inserted into the base languages. We will explain more about the experimental materials in Chapter 3. In addition, the Matrix Language Frame model (MLF) by Myers-Scotton (1993) can be used to further explain the insertional code-mixing with the incorporation of the terms Matrix language and Embedded language, which means the assimilation of the lexical items from the embedded language into a more dominant language, also being referred to as the matrix language.

However, here arises the debate of lexical borrowing (especially nouns) akin to insertional code-mixing. Sapir (1921) claims that borrowing is the transference between languages where one brings influence to the other language. In order to distinguish between lexical borrowing and code-mixing, we take consideration of Thomason (2003)’s quote: “A code-switched word (also known as code-mixing) or other morpheme becomes a borrowing if it is used more and

more frequently – with or without phonological adaptation – until it is a regular part of the recipient language, learned as such by new learners”(p.696). In other words, when the frequency use of a code-mixing word from a non-dominant language is elevated, there’s likely it will be borrowed by the matrix language. It should be noted that our experiment materials avoided using the borrowing words. Therefore, taken together with the above rules that were stated by Fabbro (1999) on language mixing sentences, the current study filtered out the highest rated nouns when we collected participants’ responses via questionnaire as we want to exclude borrowing words in our materials.

After reviewing the linguistic characteristics of language mixing, we now will discuss the neural substrates for language mixing. Case studies on brain-damaged patients have shown that pathological mixing mainly centered in the parieto-temporal structures of the left hemisphere.

Neurologist Leischner (1943, 1983) reported that mixing disorder was found in a deaf-mute polyglot aphasic. He acquired sign language as his first language, Czech as his second language and English as his third language. After experiencing strokes, he involuntarily mixed Czech and German syllables within a word, unable to express a word in different mediums such as writing, speaking and sign languages. Later autopsy revealed that the lesion mostly centered in the superior temporal gyrus and the inferior parietal lobe of the left hemisphere.

In addition, neurologist Perecman (1984) found lesion in the left temporal lobe of a Slovene-Italian-Friulian-English multilingual patient who severely mixed all of her languages

and also suffered from Wernicke aphasia. For example, patients would respond to a question by mixing English and Italian languages: “I was working with ce faccio coi…del… fare, I signori la che I faceva…” (I was working with English I do with… do… men there who did…).

Abutalebi et al. (2000) examined a case of pathological language mixing after the Armenian-English-Italian polyglot patient experienced lesion centering on the head of the left caudate nucleus. The patient developed a non-fluent output in oral productions tasks, which suggested that the damaged in the subcortical structure may cause the impairment in the mechanisms involving language selection.

In addition to neuropsychological findings, numerous studies have been initiated to investigate code mixed sentence processing (Moreno et al., 2002; Liao & Chan, 2016). Most behavioral studies have shown that significantly shorter time will be required by bilinguals in response to non-mixed sentences as compared to mixed-sentences. It was thus suggested that the processing cost in perceiving the stimuli were higher in mixed-sentences. Moreno et al.

(2002) conducted an ERP study to investigate the processing cost of English-Spanish bilinguals in language switching. Participants were requested to comprehend English sentences and idioms ending either with lexical switch (English synonyms) or code switch (Spanish translations). The result showed that the code switch condition elicited a left negative-going potential that occurred between 250 to 450 ms, the left anterior negativity (LAN). The LAN effect has often been associated with syntactic structural processing complexity, especially

related to the high demand of working memory (Kluender & Kutas, 1993; King & Kutas, 1995).

In addition, at the parietal and occipital region, a large positive complex (LPC, also known as P600) was also observed in the code switch condition. LPC/P600 has been suggested to reflect the reanalysis of complicated sentences, such as the semantically unrelated sentences and garden-path sentences (Osterhout et al., 1994; Kim & Osterhout, 2005). Therefore, the processing cost for language mixing condition was higher than that for the non-mixed condition, as participants required more efforts for stimulus evaluation.

In sum, the above studies demonstrated that language switching and language mixing are two distinct phenomena which correspond to lesions in different brain regions. Specifically, the bilateral frontal lobes and the left anterior cingulate cortex (ACC), left basal ganglia were found in pathological switching, whereas in pathological mixing conditions, the responsible brain regions mainly centered in the left superior temporal gyrus, left inferior parietal lobe, left temporal lobe, left postrolandic, parieto-temporal and basal ganglia. In addition, research has also shown that language mixing sentences, as compared to non-mixing ones, demanded greater effort and longer process time to bilingual speakers.