Monday, January 22, 2018

Processing Binding Relations in Specific Language Impairment

Pronouns are words like ‘he’ or ‘she’ that can take the place of a noun in a sentence. So instead of saying, The girl hits the ball, we can say, She hits the ball. Confusion sometimes occurs when there is more than one noun or pronoun in a sentence. For example, in the sentence, The girl splashed her, it may not be clear to the listener if the ‘her’ refers to ‘the girl’ or someone else. Some pronouns, however, provide more clues about how to connect information. In the sentence, The girl splashed herself, the pronoun, ‘herself’ (called a reflexive pronoun) tells the listener that the girl is splashing her own self. The researchers in this study were interested in whether or not children with and without a developmental language impairment (DLD; also known as specific language impairment) use the same principles for binding information with appropriate pronouns.

The researchers collected data from 46 school age children: 22 with DLD, and 24 with typically developing language. The children first heard three versions of a sentence in which there was either a pronoun, a reflexive, or a noun: The alligator knows that the leopard with the green eyes is patting him/himself/the girl on the head with a soft pillow. At the option point in the sentence, the children were presented with a picture of the actor coming just before (i.e., LEOPARD in the example sentence), and asked to decide if it was something that could be alive or not. Compared to the responses to the noun (i.e., ‘the girl’), slower responses were expected for the pronoun (‘him’) than the reflexive (‘himself’) because the reflexive pronoun activates binding with the actor. The results indicate that in general, the children with DLD were slower at responding to the picture, but showed the same response patterns as the typically developing group.

The results of this study add to the growing evidence that children with DLD show typical patterns of language development. The authors speculated that the overall slower responses of children with DLD in sentence processing tasks could reflect interference within working memory.

Blogger: Ren Lohmann is an MA student in Linguistics, supervised by Dr. Lisa Archibald.

Friday, December 15, 2017

Predicting the Birth of a Spoken Word

Early on, young children are surrounded by words, but they do not yet know what these words mean, or how to use the words themselves. Despite not yet knowing the meanings of words, the experiences and interactions that surround the usage of these words may drive the emergence of word knowledge. Laboratory studies, however, are not ideal for examining real-world experiences. In this novel study, the researchers examined the combination of factors that were most predictive of word knowledge in a naturalistic environment.

To collect these data, the researchers conducted a large-scale, longitudinal observation of a single, typically-developing child. They collected audio and video recording from all rooms of the child’s house from birth to age 3 years, adding up to 200,000 hours of data. They analyzed the space, time, and language context for each word spoken to the child. For instance, the word “breakfast” was most often spoken in the kitchen, between 8:00am to 10:00am, and was often spoken with other words such as “chew”, “yum”, and the child’s name. The main outcome measure was the age at which individual words were spoken by the child. They found that words produced in distinct spatial, temporal, and linguistic contexts were produced earlier by the child, suggesting they were easier to learn. These three factors were also strongly correlated with one another, and were stronger predictors of the age at which the child first produced a word than how frequently the word was said to the child.

Taken together, this rich observational study supports the notion that words produced in more distinctive contexts are learned earlier. It is important to note that because these data came from one child, the generalizability of these findings needs to be established. Nevertheless, this study demonstrates how multimodal data collection is valuable in understanding language acquisition. The causal structure of language acquisition is a complex puzzle, but these data provide some evidence for revealing part of this process.

Blogger: Nicolette Noonan is a PhD student in Psychology, supervised by Drs. Lisa Archibald and Marc Joanisse.