A hidden and isolating problem
Language comprehension involves many different parts of the brain working together. Despite this, most of us find language comprehension very easy and can do it very quickly.
Unfortunately, language comprehension impairments after stroke are hidden and difficult to diagnose. It's even difficult for friends and family members to recognise that their loved ones have problems comprehending language. Impairments in language comprehension can lead to the person with stroke being cut-off from their social network and finding it hard to watch TV, listen to the radio or read books.
What did the research find?
In this study, researchers measured how the brain responds to the word sounds and the meaning of words in 10 people without stroke and eight stroke survivors that resulted in a condition called Wernicke's aphasia. It's thought that brain processing of both sounds and meaning of words are damaged in Wernicke's aphasia, leading to language comprehension symptoms.
Measurements were taken using an EEG. The researchers found that brain processes involved in both the sounds of words and their meaning were impaired in the patients with Wernicke's aphasia.
Dr Holly Robson, the lead author on the paper said: “We now have increasing evidence explaining why some people have difficulties understanding language after stroke. This has nothing to do with intelligence or not knowing what words mean, rather, it's because the stroke prevents individuals accessing those word meanings. This is because the parts of the brain that analyse speech have been damaged so an accurate message cannot get through.
"We now need to understand what happens when we try and treat this problem. We can use this technique to see if our therapy is having an effect in the way that we want”.
About the researchers
Dr Holly Robson is a Lecturer in Clinical Language Sciences at the University of Reading. She was previously a Stroke Association Postdoctoral Fellow.
Dr Robson also supervises Emma Pilkington, second author on the study, who is currently a Stroke Association Postgraduate Fellow investigating jargon aphasia.
This study was funded by a Stroke Association Postdoctoral Fellowship awarded to Dr Holly Robson.