New research from UTHealth Houston has revealed insights into the brain’s role in semantic integration during reading, shedding light on the challenges faced by individuals with aphasia. The study, published in Nature Communications, found that the posterior temporal cortex is responsible for initial semantic processing, while the inferior frontal cortex plays a broader role in understanding meaning.
The researchers used intracranial recordings in epilepsy patients to observe how the brain derives meaning from phrases. They found that different areas of the language network show sensitivity to meaning across a small window of rapidly cascading activity. Specifically, they discovered that the posterior temporal cortex activates early on in the semantic integration process, while the inferior frontal cortex is particularly sensitive to all aspects of meaning.
Aphasia is a disorder that affects a person’s ability to express and understand written and spoken language. People with aphasia often struggle with semantic integration, meaning that while they can understand individual words, they struggle to make additional semantic inferences. The study’s findings suggest that both the frontal and posterior temporal cortexes disrupt semantic integration, which could explain the varying semantic deficits experienced by individuals with aphasia, especially after frontal strokes.
The researchers hope that their findings will contribute to a deeper understanding of semantic deficits in aphasia and inform future research and treatment strategies for individuals with language disorders.