Bilingualism Flashcards
What is bilingualism? What factors need to be considered?
- 60% of the population is multilingual (43% bilingual)
- not one definition, continuum with high variability across a person‘s life span
Factors: - level of proficiency (speaking, writing, listening, reading)
- language competence (dominance and balance)
- frequency of use (context, domain, modality)
- number of languages (multilingualism, languages and dialects)
- age of acquisition (AoA, simultaneous, sequential, late)
What is Broca‘s area?
= inferior frontal gyrus (opercular part BA 44, triangular part BA 45)
- important for speech production (motor area)
- lesion lead to impaired speech production, but comprehension is normal
What is Wernicke‘s area
= left superior temporal gyrus (part of BA22)
- important for language comprehension
- lesions lead to impaired language comprehension, patients have trouble understanding meaning and constructing meaningful utterances, production is normal
What is the arcuate fasiculus?
= connection between Wernicke‘s and Broca‘s area
- potentially involved in conceptual representation
Do bilingual speakers use different brain areas for their languages?
No: Scoresby-Jackson had a bilingual patient with severe language loss in only one language -> concluded that both languages must use different parts of the brain. However, Pitres (almost 30yrs later) correctly concluded that the same brain areas but different neuronal circuits are used.
What is lateralisation and where can language be found?
= area where primary function occurs
- initial belief: right-handed people have speech centre on left hemisphere, left-handed people have speech centre on right hemisphere
- not as easy -> language in most people left-lateralised BUT conflicting results in bilinguals - left-lateralised or bilateralised
- main modulator of lateralisation = AoA -> early bilinguals - bilateralised, late bilinguals mostly left-lateralised
Some lateralised functions:
Left hemisphere:
- linear reasoning (grammar and word production)
- filling in forms: letters and numbers
- temporal judgments
Right hemisphere:
- holistic reasoning (metaphors and intonation)
- feelings and intuition, comprehension of emotional content
- prosody, sentence function (command, question, statement)
Activation in early vs late bilinguals
Broca‘s area:
- AoA -> different areas
- proficiency -> no differences
Wernicke’s area:
- no differences
- semantic task -> no differences
- non-semantic task -> differences
Activation in L1 vs L2:
- not localisation of activation but degree of strength of activation differed
- stronger activation in L2 than L1 and mostly in IFC -> more effortful, less efficient
Activation of L1 vs L2 in early vs late bilinguals
- low/moderate proficiency -> smaller and more distributed activation across hemispheres
- high proficiency -> similar activations of L1 and L2
- L2 more activated areas in late than early bilinguals
Comprehension in bilinguals
Flexible and variable -> plasticity
- exposure to L2 and proficiency modulate more than AoA
Selective or non-selective access?
- both languages activated in isolation and at all levels of representation (non-selective)
Production mechanisms may only influence comprehension when context is provided
Production in bilinguals
potentially parallel activation -> language interference
language-specific (selective) and non-specific (non-selective) mechanisms
- cognitive control and inhibition processes more pronounced in low proficiency bilinguals
- possibly different mechanisms on high proficiency and low proficiency bilinguals
Activation of anterior cingulate and bilateral subcortical structures (putamen and head of caudate nucleus) during translation tasks
- possibly due to need for greater coordination of mental processes
How does bilingualism affect brain functions?: Research questions
1) bilingual advantage debate
- neither proven nor disproven (also what is an advantage and do we really need to speak in terms of advantages?)
- does bilingualism enhance cognitive performance?
2) emergence of bilingualism and cognitive abilities -> what came first?
- unsure what emerges first
-> does bilingualism enhance cognitive abilities?
OR
-> do cognitive abilities support bilingualism?
- complex interplay of genetics, language use, environmental factors and demands, individual differences
What is code-switching?
= practice of alternating between two or more languages in a single conversation or context (does also involve switches between dialects and formality)
- found in multilingual communities (but also among monolinguals) and shaped by cultural, situational and cognitive factors
Three types of code-switching according to Poplack (1980)
1) tag-switching (discourse markers): mixed languages within a sentence
2) intersentential code-switching: switching between sentences
3) intrasentential code-switching: switching within sentences
How does code-switching impact cognitive abilities?
Cognitive control and task switching
- idea: switching between languages requires inhibition of the non-target language and switching to the target language
+) frequent code-switchers perform better in Stroop and Flanker tasks due to improved inhibitory control
-) frequent switchers show slower responses in tasks requiring inhibition, indicating potential cognitive costs
-> increased cognitive load may result from constant engagement with competing linguistic systems
Working memory
- idea: switching between languages relies on working memory to manage competing language systems
+) enhanced WM capacity in frequent switchers (n-back task)
-) no bilingual advantage observed in n-back tasks, suggesting that WM benefits may not generalise across all bilinguals
-> contradictory results, different factor (task complexity, population characteristics, methodological limitations … er ) likely contribute to mixed results
