Babies pick up complex grammar rules at 4 months, study shows
Babies as young as 4 months are able to identify grammar rules in an unfamiliar language, new EU-funded research reveals. The study, published in the journal PLoS ONE, significantly adds to our understanding of how babies learn languages. The study was funded by the EU through the CALACEI ('Universal and specific properties of a uniquely human competence. Tools to study language acquisition in early infancy: Brain and behavioural studies') project, which received EUR 15 million under the 'New and emerging science and technologies' (NEST) budget line of the Sixth Framework Programme (FP6). Infants pick up languages with a speed and apparent ease that appears startling to parents and researchers alike. Studies on babies have shown that even newborns are able to discriminate between different phonemes within syllables. In addition, very young babies appear to be able to recognise the relationships between adjacent syllables that often occur together. However, very often grammatically linked elements do not occur next to each other in a sentence; for example, in the phrase 'is singing', 'is' is separated from 'ing' by the stem 'sing'. 'The learning of these non-adjacent dependencies is much more difficult than learning adjacent dependences,' the researchers write. In fact, previous studies have suggested that children may not understand these kinds of rules until the age of 17 or 18 months. 'That seemed to be very late,' commented Professor Angela Friederici, Director of the Department of Neuropsychology at the Max Planck Institute for Human Cognitive and Brain Sciences in Germany. In this study, Professor Friederici and her colleagues sought to determine if 4-month old babies could pick up on these non-adjacent dependences. They picked 4-month olds because research has suggested that babies of this age already have some verbal memory and phonological discrimination skills. The researchers started by effectively teaching 4-month old German babies some basic Italian. For a little over three minutes, the babies listened to sentences in Italian featuring two simple constructions. One kind of phrase involved the construction 'sta X-ando' (i.e. 'is X-ing'); an example of this type of phrase is '[il fratello] sta cantando', which means '[the brother] is singing'. The second kind of phrase included the construction 'può X-are' (i.e. 'can X'); an example here is '[la sorella] può cantare', which means '[the sister] can sing'. After listening to correctly formed Italian sentences like these for three minutes, the infants underwent a little test, during which they heard both correct and incorrect sentences. Incorrect sentences muddled up the constructions, saying things like 'la sorella può cantando' ('the sister can singing') or 'il fratello sta cantare' ('the brother is sing'). In total, the infants underwent four learning phases, during which they listened to a total of 256 correct sentences; their total learning time was only just over 13 minutes. During the experiment, the babies' brain activity was measured. In the early test phases, there was little difference in the pattern of activity registered when the babies heard incorrect Italian sentences. However, by the fourth test period, very different brain activation patterns emerged, indicating that the infants had learnt that 'sta' goes with '-ando' and 'può' goes with '-are'. 'The present data demonstrate that 4-month-old infants can extract dependencies between non-adjacent elements in sentences from brief exposure to a natural, non-native language,' the researchers conclude. 'The emergence of the sensitivity to the grammatical regularities indicates that infants extracted the dependencies within the two pairs of non-adjacent elements (i.e. the auxiliaries and the respective verb suffixes) from correct sentences they had heard during the training phases.' 'Naturally, at this age infants do not notice content-related errors,' said Professor Friederici. 'Long before they comprehend meaning, babies recognise and generalise regularities from the sound of language.' According to the researchers, the brain activity patterns of the 4-month old German babies when exposed to errors looked more like those of adult native Italian speakers. Native German speakers who were learning Italian as a second language did not respond in the same way. According to the researchers, '[this] suggests that native learning may be restricted to a sensitive time window during development.'For more information, please visit: Max Planck Institute for Human Cognitive and Brain Sciences:http://www.cbs.mpg.de/index.htmlPLoS ONE:http://www.plosone.org
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Germany