Scientists explore capabilities involved in language acquisition

Different disciplines have dealt with how human beings acquire language. As it has been the subject of much debate since its beginnings, diverse opposing theoretical currents, which have debated the psychological, neurological and social factors involved in the process, have emerged.

Alejandro Wainselboim, CONICET assistant researcher, is part of a group of researchers at the Laboratory of Linguistics and Experimental Neurobiology of the Language at the Human, Social and Environmental Sciences Institute (INCIHUSA in Spanish). At this laboratory, scientists study the cognitive processes involved in the acquisition and use of language, that is to say, the mechanisms the brain uses to codify and decode messages. To put it simply: speak, read and understand.

The researchers state that during the first stage, human beings are capable of acquiring any language through exposure: maternal, second or third language. This means that through the interaction with other individuals, people can learn the necessary resources to communicate. Besides, this capability makes people acquire complex issues, such as grammar (the way in which words are ordered) or semantics (the meaning of words), in an inferential and implicit way without the need to be explained.

Wainselboim explains that around the age of five a child has the grammar of an adult: “When a kid is five or six has a vocabulary made up of thousands of words, which can include among 30 and 50 thousands. Only some hundreds of those words were learnt through questions, and I exaggerate it. So the greatest part of the vocabulary was learnt implicitly, basically by inferring the meaning of a word according to the context where it was heard.”

The neuroscientist comments that this phenomenon responds to a capacity of the brain that allows it to store statistics on events occurrence, qualities, and words that were heard in different events. “Individuals can store co-occurrence statistics between environmental aspects and linguistic terms heard in different events”, the researcher states. So this allows individuals to understand the meaning of the words and link them to situations and objects.

Nevertheless, the researchers agree with the previous studies that state that individuals begin to lose this capacity over the years. “The language acquisition capacity through exposure to the context apparently will disappear over the second childhood, from six to twelve years old, and in adolescence we do not have it. An adult can learn an unlimited number of languages, but the way is totally different, it is formal learning with grammatical rules, meanings of words, everything is specific”, the scientist explains.

A list of neurolinguistic experiments that determine the neuron activity during the learning process of new words allowed scientists to observe that healthy adults proved to be capable of learning not only the meaning of new terms inferentially but also the implicit grammatical (combinatorial) rules of an artificial grammar designed for the study. “This result makes us think that adults have the same learning capacity that appears in a child’s brain but to a lesser degree”, the biologist describes.

The researcher states that in a complex environment such as the social system, the capacity of statistical associations between stimuli would not be ‘powerful enough’ so as to make an adult learn through simple exposure.

The following step for the group is to understand the changes that occur in the brain and make inferential and implicit learning lesser in adults. For Wainselboim, one possibility is the fact that adults can generalize at the expense of a lesser capacity of paying attention to details, thus reducing the statistical learning capacity in complex natural contexts.

Although the scientists think that this can be a clue in the difference with children, the study is under development: “We do not know the changes that occur in adults, but we have one hypothesis. So far we have worked with adults, the next step is to work with children so as to make comparisons”, the researcher concludes.