Language is often referred to as the window into the brain because language abilities can index many psychiatric and neurodevelopmental conditions.
As shown on the right, the American Psychiatric Association uses certain language-related phenotypes as diagnostic indicators for various psychiatric conditions.
Despite the clinical link between language and psychiatric conditions and the knowledge that both emerge developmentally through interconnected neural and cognitive networks in the brain, limited strides have been made to understand this relationship on the genetic level.
The phenotypic link between psychiatric conditions and language.
Our lab's goal is to characterize the shared genetic basis of language and psychiatric conditions, which will better inform personalized treatments and interventions.
Characterizing Language Phenotypes
To characterize the genetic basis of language, language phenotypes (which manifest diversely in neuropsychiatric conditions) need to first be effectively categorized and classified. Traditional language assessments can be timely and costly to administer. Thus, the lab first focused our attention on developing an adaptable and easily employable language assessment.
We did this through two means: 1) a physical booth in a hospital clinic waiting room where participants completed various language tasks and 2) a comprehensive and interpretable web-based speech and language questionnaire.
A language task participants completed in the booth.
Our results showed that the language screener deployed in the booth was a powerful platform for scalable deep phenotyping of language and other cognitive abilities.
"The Booth"
Our first deployment of a language assessment or screener was in a soundproof booth in a hospital clinic waiting room. Participants were asked to complete various language performance tasks, such as listing as many words that started with a particular letter and reading as quickly as they could. Individuals also completed a mood survey, allowing us to assess the potential impact of mood on the various language tasks.
Interested in participating?
You can find the Booth on the first floor of the University of Iowa Health Care: Scott Boulevard Clinic.
Characterizing the Genetic Basis of Language Phenotypes
To understand the genetic basis of language phenotypes, we have conducted a range of genetic and genomic analyses on the sequenced genomes of individuals with language impairments, and individuals with psychiatric conditions, chiefly autism. These analyses included polygenic risk score correlations, heritability analyses, a genome-wide association study (GWAS), and a rare-variant exome-wide association study.
Integrated together, our research has shown that language ability has a complex, polygenic genetic architecture, impacted by both common and rare genetic variation.
We have also discovered the genetic variation underpinning language ability is also linked to the development of general cognitive ability and neuropsychiatric conditions. Interestingly, however, we did not detect a shared genetic basis between autism and specific language impairments.
Future Directions
Our hope is this research leads to the development and clinical use of personalized interventions and therapeutics for those with language difficulties and psychiatric conditions.