What is the best way to help individuals learn new words or re-learn words after brain damage?

Funding Round: 4 2016-2018

Research Question: What is the best way to help individuals learn new words or re-learn words they have lost after brain damage?  Does training a target along with similar words help or hurt learning?

Interdisciplinary Approach: The project applies findings from the cognitive science of language production to education. In addition, it proposes a parallel investigation of language learning in typically-developing children learning their second language and brain-damaged adults re-learning the language they have lost. As such, the project lies at the intersection of the three fields of cognitive science, education, and medicine.

Potential Implications of Research: The research advocates ways of reassessing the efficacy of educational methods based on basic cognitive research, and will uncover a more efficient way of training language for new learners or those with language impairment.

Project Description: Language is a critical tool for humans to adapt to their surroundings, express their needs and wishes, and understand others’ thoughts and needs in return. When healthy individuals are placed in an environment where no one speaks their language, they often feel distressed and frustrated. This frustration is multifold in individuals who have lost their ability to speak or understand language due to brain damage, and therefore must relearn their native language. As this example highlights, language learning plays a critical role in both medicine and education.

This project focuses on one of the most basic aspects of language learning, namely, learning the names of objects/entities, which is an integral part of all second-language learning programs in schools, as well as speech therapy programs for individuals with language impairment. In traditional formal foreign language courses and language rehabilitation sessions, trainers teach the names of objects to the learner by organizing the training session around a theme, such as “animals,” “fruits,” or “clothing items.” If the session’s theme is “animals,” language learners are trained on the names of various animals such as cat, dog, lion, and horse all in one session. Having a common theme can help the learner by strengthening the brain network for all the related items. But at the same time, it could cause confusion for the learner, because dogs and cats are more similar than apples and cats. In fact, recent research in language production has shown that when people have to name the picture of a horse after having named pictures of dog and cat, they are slower and more likely to make an error, compared to when they name the same picture (horse), but after having named unrelated pictures such as pen and shoe. The interference induced by having named similar objects can be particularly pronounced in individuals with brain damage. However, to date, little research has explored the effect of similarity of items in a training set on long-term learning, and the few studies that have attempted to look at the issue are inconclusive.

We will conduct a parallel investigation of similarity effects in a training set during learning words in a second language (French) in typically-developing 7-8 year olds in Baltimore schools, and re-learning words in native English in adults with brain damage. In both cases, we will train individuals for several weeks on words presented either in the context of similar words, or in the context of unrelated words. We will then assess the effect of contextual similarity on short-term learning (right after training), and long-term retention (1 week, 3 weeks, 6 weeks, and 3 months after training). In addition, we will measure each individual’s ability to effectively resolve interference from related items using a battery of non-verbal cognitive tasks, in order to better understand if different learners are more or less susceptible to the negative effects of having related items in a training set. Collectively, these results will shed light on the optimal context for training labels in language learning settings across individuals with brain damage attempting to relearn a language and also healthy populations attempting to learn a second language.