Brain research helps unlock secrets of language disorders
Language disorders comprise a spectrum of communication impairments. These include comprehension and the production of speech, as well as potential difficulties in reading and writing. “Disorders such as dyslexia(opens in new window) often manifest in ways that are specific to each individual,” notes OsciLang project team member Craig Richter , staff scientist at the Basque Centre on Cognition, Brain and Language(opens in new window) (BCBL), Spain. “Therapeutic interventions need to be adapted to each individual’s impairment, age and level of competency. This has made language disorders quite difficult to treat.” Designing therapeutic interventions is further confounded by the complexity of the brain mechanisms that contribute to these disorders. “Significant progress has been made in determining key structures and interactions that underlie language production and comprehension,” says Richter. “However, determining the key interactions between these systems, and other cognitive systems, such as attention, remains a significant challenge to researchers.”
Understanding brain processes
The aim of OsciLang was to develop new ways of assisting children with difficulties in reading and speech processing. The project builds on research that shows how conversational partners naturally adapt their verbal and non-verbal communicative actions to mimic, or more closely resemble each other. “Ongoing brain rhythms synchronise to rhythms present in speech,” explains Richter. “This is known as brain-speech entrainment(opens in new window) (BSE). Importantly, research has shown that BSE is compromised in children with dyslexia. Our aim therefore was to design a method to enhance BSE.” The team saw that one way of achieving this could be through the use of a brain-computer interface(opens in new window) (BCI). This device records and processes brain activity during speech, and then feeds this information back to the user in a simple to understand way, such as a visual readout. “We wanted to record electrical brain activity during BSE, and then find a way of relaying this activity to the user,” adds Richter. This could open the door to new ways of manipulating the brain processes responsible for reading and speech, and developing therapeutic processes targeted at the individual. Evaluations were carried out on human data, obtained while participants listened to audiobooks. These evaluations enabled the team to identify strengths and weaknesses of various methods of tracking and reporting brain activity, and to tailor their approach for maximum performance. “This neurofeedback approach(opens in new window) we are developing represents a significant advance in therapeutic technology of language impairments,” says Richter. “It’s also a substantial departure from current therapeutic methods.”
New approaches to speech impairments
Richter hopes that the progress made will eventually lead to the development of small, cheap and easy to operate BCI systems that can be deployed in schools and homes. “Quite simply, our hope is to develop a therapeutic system to assist in reading and speech processing difficulties,” he explains. “At present, these systems are typically large, expensive and difficult to operate. The advances we have made mean that a simplified BCI system is quickly becoming a reality.” Next steps include determining the most effective ways of delivering feedback to the user and motivating improvement in BSE. Further improvements could also be made by preprocessing the brain’s electrical activity in real time, to further extract only the necessary information to determine BSE. The project’s work should also be of interest to the academic community. The development of BSE metrics will give researchers a window into how language is processed and help them to develop a better understanding of BSE.