Final Report Summary - INFANTBILINGUALBRAIN (Language learning in monolingual and bilingual infants: Evidence from electrophysiological and optical signals)
Bilingual infants have to deal with two languages at the same time. In particular, having to learn to associate words to a concrete object represents a quite challenging task for bilingual infants as they have to learn that 2 words (in 2 languages) belong to one object and have to be associated together. Such a setting led to delayed processing compared to monolingual infants in previous studies due to the high computational load bilinguals are faced with. However, other studies show that bilinguals possess more efficient processing mechanisms leading to an increased cognitive flexibility. The present study aimed at testing these different hypotheses in order to get clearer insights into language learning processing mechanisms in mono- and bilingual infants.
Newborns can acquire any language of the world. From birth on infants are able to discriminate virtually all linguistic contrasts including those which are irrelevant for their native language. This ability decreases with age and more importantly with increasing competence in a specific language. For this reason we opted to contrast native and non-native regularities of a linguistic aspect crucial during initial word learning. Phonotactics describes the combinatory rules of phonemes in a given language and represents a prelexical cue relevant for segmentation and lexical access.
The objectives of the present project included the following research questions:
- How are native and non-native phonotactic rules acquired during infancy by monolinguals and bilinguals?
- Do bilinguals show an increased flexibility or are they faced with an increased cognitive load while processing native and/or non-native phonotactic rules embedded in a challenging word-object associative learning context?
- Do bilinguals adopt different learning strategies at different ages?
- Which brain areas are recruited during language learning in mono- and bilinguals?
In order to test these hypotheses we performed a language learning study including a pretest, a semantic training, and a posttest (see Figure 1). During pre- and posttest phonotactically native (i.e. corresponding to German, the native language of monolinguals and one of the native languages of bilinguals) and phonotatically non-native (i.e. corresponding to Slovak phonotactic rules, non-native for both monolinguals and bilinguals) pseudowords were acoustically presented. Half of native and non-native pseudowords were integrated in the semantic training where they were combined with pseudoobjects in either a correct (i.e. multiple presentation of the same pseudoword with the same pseudoobject) or an incorrect pairing (i.e. multiple presentation of the same pseudoword with different pseudoobjects). Four groups of participants were put under investigation: 6- and 18-month-old German monolinguals and 6- and 18-month-old German-Italian bilinguals. These age groups were selected to be able to contrast prelinguistic infants with infants in the midst of the vocabulary spurt and thus being faced with language comprehension and production.
In order to track neuronal processing mechanisms involved in language processing and language learning we adopted two neuroscientific methods simultaneously, the electroencephalography (EEG) and the functional near-infrared spectroscopy (fNIRS) (see Figure 2). The former provides an excellent temporal resolution in the range of milliseconds and is thus able to online track linguistic processing mechanisms in the brain. The latter provides a good spatial resolution and can thus detect brain areas involved in different linguistic processes. With respect to the fNIRS we primarily focused on lateralization as this might reflect developmental stages from more immature to an adult-like processing.
All measurements were performed in the “Lab for Cognitive Neuroscience” (head: Dr. Sonja Rossi) of the Medical University of Innsbruck.
Findings from both neuroscientific methods show learning effects for trained pseudowords in both 6 and 18-month-olds. This seems to indicate that monolinguals can successfully learn from a semantic training. The fNIRS results in this regard, however, reveal a bilateral recruitment in younger infants and this lateralization turns into an adult-like pattern in older infants. This pattern confirms previous studies on word processing that initially both hemispheres are necessary and ones infants increase competences they efficiently use only one hemisphere, in the case of phonotactic processing they predominantly rely on the left hemisphere.
As expected the processing dynamics in bilingual infants are more complex. Bilingual 6-month-olds seem to show increased learning flexibility but mainly for native phonotactic rules and non-native untrained rules. Thus, bilinguals seem to benefit from the semantic training for familiar rules and from a more acoustically driven passive listening for foreign language rules. The increased flexibility is supported by an adult-like left-hemispheric lateralization which is impressive at this young age. 18-month-old bilinguals, however, seem to suffer more from the ambitious semantic training evidenced by either showing no modulations or by still recruiting both hemispheres. Interestingly, for untrained items the EEG results showed similar processing mechanisms as for monolinguals, suggesting a benefit from the passive acoustic presentation rather than from the difficult semantic training.
These findings have several societal implications as they point out that learning dynamics in bilinguals are 1) different from monolinguals, thus they have to be handled differently in language learning settings, and 2) the learning development does not behave linearly, thus it depends on the age of the bilingual child whether a stronger benefit can be recorded from different trainings (e.g. passive listening training, semantic training). The observation of learning effects emerging from the passive acoustic presentation from pre- to posttest definitely necessitates further investigation.
The results of the present project will have a direct impact in developing adequate language learning settings promoting maximal learning achievement accounting for the optimal requirements of a monolingual and bilingual learning environment (e.g. in day nurseries, playing groups etc.) .
The present study does not only provide evidence for the usefulness of neuroscientific methods for investigating complex cognitive processes but specifically emphasizes the importance of multi-methodological approaches as the consideration of the results of both EEG and fNIRS in the present project provide a more detailed picture than looking only at one methodology.
Contact details:
“InfantBilingualBrain” - Language learning in monolingual and bilingual infants: Evidence from electrophysiological and optical signals
Scientist in charge: Prof. Dr. Gerhard Schüßler
Scientific principal investigator: Dr. Sonja Rossi
Medical University of Innsbruck (Austria)
Email: gerhard.schuessler@tirol-kliniken.at; sonja.rossi@i-med.ac.at
Newborns can acquire any language of the world. From birth on infants are able to discriminate virtually all linguistic contrasts including those which are irrelevant for their native language. This ability decreases with age and more importantly with increasing competence in a specific language. For this reason we opted to contrast native and non-native regularities of a linguistic aspect crucial during initial word learning. Phonotactics describes the combinatory rules of phonemes in a given language and represents a prelexical cue relevant for segmentation and lexical access.
The objectives of the present project included the following research questions:
- How are native and non-native phonotactic rules acquired during infancy by monolinguals and bilinguals?
- Do bilinguals show an increased flexibility or are they faced with an increased cognitive load while processing native and/or non-native phonotactic rules embedded in a challenging word-object associative learning context?
- Do bilinguals adopt different learning strategies at different ages?
- Which brain areas are recruited during language learning in mono- and bilinguals?
In order to test these hypotheses we performed a language learning study including a pretest, a semantic training, and a posttest (see Figure 1). During pre- and posttest phonotactically native (i.e. corresponding to German, the native language of monolinguals and one of the native languages of bilinguals) and phonotatically non-native (i.e. corresponding to Slovak phonotactic rules, non-native for both monolinguals and bilinguals) pseudowords were acoustically presented. Half of native and non-native pseudowords were integrated in the semantic training where they were combined with pseudoobjects in either a correct (i.e. multiple presentation of the same pseudoword with the same pseudoobject) or an incorrect pairing (i.e. multiple presentation of the same pseudoword with different pseudoobjects). Four groups of participants were put under investigation: 6- and 18-month-old German monolinguals and 6- and 18-month-old German-Italian bilinguals. These age groups were selected to be able to contrast prelinguistic infants with infants in the midst of the vocabulary spurt and thus being faced with language comprehension and production.
In order to track neuronal processing mechanisms involved in language processing and language learning we adopted two neuroscientific methods simultaneously, the electroencephalography (EEG) and the functional near-infrared spectroscopy (fNIRS) (see Figure 2). The former provides an excellent temporal resolution in the range of milliseconds and is thus able to online track linguistic processing mechanisms in the brain. The latter provides a good spatial resolution and can thus detect brain areas involved in different linguistic processes. With respect to the fNIRS we primarily focused on lateralization as this might reflect developmental stages from more immature to an adult-like processing.
All measurements were performed in the “Lab for Cognitive Neuroscience” (head: Dr. Sonja Rossi) of the Medical University of Innsbruck.
Findings from both neuroscientific methods show learning effects for trained pseudowords in both 6 and 18-month-olds. This seems to indicate that monolinguals can successfully learn from a semantic training. The fNIRS results in this regard, however, reveal a bilateral recruitment in younger infants and this lateralization turns into an adult-like pattern in older infants. This pattern confirms previous studies on word processing that initially both hemispheres are necessary and ones infants increase competences they efficiently use only one hemisphere, in the case of phonotactic processing they predominantly rely on the left hemisphere.
As expected the processing dynamics in bilingual infants are more complex. Bilingual 6-month-olds seem to show increased learning flexibility but mainly for native phonotactic rules and non-native untrained rules. Thus, bilinguals seem to benefit from the semantic training for familiar rules and from a more acoustically driven passive listening for foreign language rules. The increased flexibility is supported by an adult-like left-hemispheric lateralization which is impressive at this young age. 18-month-old bilinguals, however, seem to suffer more from the ambitious semantic training evidenced by either showing no modulations or by still recruiting both hemispheres. Interestingly, for untrained items the EEG results showed similar processing mechanisms as for monolinguals, suggesting a benefit from the passive acoustic presentation rather than from the difficult semantic training.
These findings have several societal implications as they point out that learning dynamics in bilinguals are 1) different from monolinguals, thus they have to be handled differently in language learning settings, and 2) the learning development does not behave linearly, thus it depends on the age of the bilingual child whether a stronger benefit can be recorded from different trainings (e.g. passive listening training, semantic training). The observation of learning effects emerging from the passive acoustic presentation from pre- to posttest definitely necessitates further investigation.
The results of the present project will have a direct impact in developing adequate language learning settings promoting maximal learning achievement accounting for the optimal requirements of a monolingual and bilingual learning environment (e.g. in day nurseries, playing groups etc.) .
The present study does not only provide evidence for the usefulness of neuroscientific methods for investigating complex cognitive processes but specifically emphasizes the importance of multi-methodological approaches as the consideration of the results of both EEG and fNIRS in the present project provide a more detailed picture than looking only at one methodology.
Contact details:
“InfantBilingualBrain” - Language learning in monolingual and bilingual infants: Evidence from electrophysiological and optical signals
Scientist in charge: Prof. Dr. Gerhard Schüßler
Scientific principal investigator: Dr. Sonja Rossi
Medical University of Innsbruck (Austria)
Email: gerhard.schuessler@tirol-kliniken.at; sonja.rossi@i-med.ac.at