Costs of bilingualism. What was the old view?
- hardly learns either language perfectly
- diminishes child's power of learning other things
Costs of bilingualism
- receptive vocabulary at preschool and early school years
- Gollan et al
- temporary word finding failures (tip-of-the-tongues, TOTS)
- Experimentally-induced TOTs: read definitions of infrequent words and try to name them, and asked whether they felt they knew
- frequnecy effect - exposed to more words
- TOTS for proper names (same for different languages) show no difference for bilinguals or monolinguals
Language benefits of bilingualism
- Peal and Lambert - positive correaltion between bilingualism and intelligence
- Verbal IQ (Bialystok)
- when other factors (like socio-economic status) controlled
- eg. mental flexibility, think more abstractly, think independently of words, easier concept formation
Another early benefit of bilingualism
- Understanding that objects can have more than one name
- age 4-6 - bilingual kids accept this much more
- monolingual English or Afrikaans vs bilingual
- 2 questions: 'could you call a cow a dog and a dog a cow? and if you make up name for things, can you call dog a cow?
- not just 1-to-1 mapping of words
- helpful for language learning and metalinguiostic knowledge
Describe model that explains process of L2 learning.
- Revised Hierarchical Model (Kroll & Steward)
- during intiial stages of L2 learning, meaning of L2 words accessed through corresponding L1 translation
- As L2 develops, link between L2 and meaning become stronger, and no longer have to rely on L1
Evidence for revised hierarchical model?
- Kroll & Steward
- non-fluent Dutch bilinguals
- Time taken for L1-->L2 translation slower than L1--> L2 (when word list were semantically related)
- no semantic effect in L2-->L1 (lexical link)
- For L1-->L2
Bilingual brain. Brain region differences between L1 and L2?
- Lots of studies using (word generation, picture naming, semantic decision, sentence reading)
- Indefrey: meta-analysis
- L1 and L2 activate similar areas
- L2 more frontal activity when lower proficiency or late learning onset
- Stronger activation - compensating by recruiting more processing pwoer
Another study about different regions activated in late acquisition?
- De Bleser et al (2003)
- Dutch-French bilingual (acquired at age 10)
- Picture naming task
- Cognates = word with same meaning and similar sound in two languages (eg. tomato, tomate)
- Differences in activation only when French non-cognate words used
- inferior frontal and temporo-parietal areas
Evidence for flexibility of brain to learn L2?
- Chinese speakers' learning of Dutch over time
- after 6months, same brain regions (left frontal area) active as when Chinese or Dutch people speak L1 (tested 3, 6, 9 months)
- test: listening to sentences and deciding whether they were describing visual scene
- when listening to L1 sentences, the left inferior frontal gyrus more active for sentence than word list (eg. the blue square is pushed away by yellow circle. Vs square, blue, yellow, push)
Which brain areas seem to be used for controlling interference of non-target language? Early acquisition
- Nonlanguage-specific brain areas (eg. left middle prefrontal cortex)
- Participants instructed to name picture only when word started with constonants or vowels
- half of words so that in both Spanish and German, the response was the same and in the other half, different
- ERP and fMRI showed phonological intereference in bilinguals but not in monolinguals
- non-lganuge specific areas such as left middle prefrontal cortex important
- LINK to better executive control!
- THAT SAID: this study also shows for early acquisition, the brain areas recruited is very similar to monolinguals in picture-naming tasks
Structural changes when L2 is learned?
- Mischelli et al (2004)
- increase density of grey matter in
- left inferior parietal cortex
- degree of change depends on age and profiency
- Unclear functional significance but clear that structural changes happen
Hypothesis for how the right word in the right language.
- Green's suppression hypothesis - suppress word in non-target language
- semantic nodes; lexical nodes (this needs to be supressed) which connects it to phoneme nodes
- However, also can be explained by a simple stronger activation in target language
Evidence for suppression hypothesis.
- Meuter and Allport (1999)
- Switching task
- Switch trial and non-switch trial
- Name digits in language indicated by digit colour (black = english; red = spanish)
- Non-switch: L1 faster than L2
- Switch: L2-->L1 slower than L1-->L2
- Spillover effect of strong L1 suppression
- naming weaker languge requires active inhibition of stronger competitor language
List evidence for cognitive benefits (non-linguistic) of bilingualism.
- 1. Better at simon task
- Simon task less affected by ageing
- Better when STM was more taxing
- 2. Better at Towers Task
- 3. Latwer onset of symptoms for Alzheimers
More on the benfits of Simon task.
- Bialystok et al (2004)
- Participants need to overcome conflicting cues to make decision
- congruent response: need to make left hand resposne when square is left
- incongurnet: need to make left hand response (because of blue square) but is on the right of screen
- Less interference from conflicting cues in bilinguals
- Simon task decreases with age, but bilinguals less affected by ageing
- NOT to do with differences in response speed - control experiment where there was no conflict - monolinguals and bilinguals equally fast
- Advantage for bilinguals in Simon task when short-term memory load more taxing
- Refelct life-long practice with suppression or with decision-making in conflicting contextsseem to be better able to cope with conflicting info and offset age related losses in executive processes
- Children - able to resist misleading info
- need to decide which tower has more blocks
- bilingual chidlren better at recognising that shorter tower can contain larger number of blocks
- Craik et al (2010)
- bilingualism correlates with delayed onset of progressive neurodegeneration
- Bilingual Alzheimers patients show onset of symptoms 5.1 years later
- language experience may contribute to cognitive reserve, compensating for effects of neuropathology
Just on the bilingual brain point - what does Indefrey also suggest?
- Lexical vs compmositional processes
- Not much change in temporal --> which is associated with lexical
- Change more in left posterior IFG (inferior frontal gyrus) --> compositional
- anterior cingulate too: related to attentional demands and error detection
- L2 processing affected by proficiency, age of onset and exposure
- bilingualism associated with costs and much wider-reaching benefits
- Bilingual lexical access non-selective: words from both languages activated, and suppression is needed
- Brain areas activated by L2 overlap with L1 - language membership not overly important factor in organising bilingual lexicon (that said, there are differences)