Aphasia is a language disorder caused by damage to the area of the brain that controls language. It often occurs as a result of a stroke, brain tumor or neurodegenerative disease such as Alzheimer’s disease.
Bruce Willis, Hollywood actor and star of crystal jungle, recently announced who was retiring after being diagnosed with aphasia. This disorder affects a person’s ability to speak or understand others coherently.
Many people had never heard of aphasia until this sad news came out, which may come as a surprise given that 300,000 new cases are diagnosed each year in the EU.
A troubling diagnosis
“People tend to focus on causes,” says Dr. Nicoletta Biondo, a psycholinguist at the University of California, Berkeley. “However, not being able to communicate all of a sudden is a terrible thing. One day you wake up and realize that you have lost your ability to speak or understand others.
Biondo continues: “Aphasia is a big unknown, but lately more and more research is being done on this subject. We hope this will help us better understand how the language system works and provide a scientific basis for designing treatments to improve the quality of life of people with aphasia.” Any damage to the part of the brain that deals with language can cause aphasia. The nature of the symptoms varies depending on the location and size of the lesion.
Some people with aphasia just can’t remember how to say “orange.” Others may be able to write “orange” but unable to read the word, and others may say “apple” instead of “orange” and insist that it is correct. There are also those who, trying to pronounce “orange”, end up emitting a pronunciation that has nothing to do with the word. Other people are unable to repeat “orange” after someone has told them to, and there are cases where they don’t even understand the meaning of “orange”.
Different subtypes
“With better diagnostic tools, we will be able to identify which aphasia subtype a person is suffering from, so that medical staff can recommend the appropriate treatment without wasting time,” says Seçkin Arslan, neurolinguist and director of the research project. ProResA, funded by the EU, whose objective is to better understand the relationship between aphasia and the use of pronouns. “Today, there is no method to end aphasia, but there are treatments to maintain language ability longer.”
Primary progressive aphasia (PPA) is a relatively rare form of the disease, although its prevalence is increasing as the population ages. It is usually caused by a stroke or progressive degeneration of the brain (for example, in people with dementia).
People with APP often show unusual use of pronouns (words like you, her, or that). Instead of referring to a person or object by name, they prefer to use the pronoun.
“Pronouns can be difficult to process because they require memory to function properly. When a person hears a noun or noun, they have to reactivate in their memory the memory of the object or person they are talking about. This is not that pronouns are the most important elements of grammar, but they are a small detail that can be used to determine the impact of an illness or stroke on general language proficiency,” explains Arslan.
The ProResA team seeks to better understand the markers of aphasia and to develop tools to accelerate its diagnosis. They will be able to predict the development of aphasia even in people who do not yet show obvious symptoms of the disease and will allow earlier identification of degenerative brain disorders such as Alzheimer’s disease.
Currently, the international standardized tests for the diagnosis and the determination of the degree of aphasia are only available in English, which does not allow to establish a comparison between countries on the severity of aphasia.
To date, the project Aphasia Investigator Collaborationsfunded by the EU, and its many international partners have adapted standardized assessment tools for aphasia in 15 languages.
eye tracking
For the first time, data is being collected using eye-tracking technology, a tool that has proven to be very useful in diagnosing dementia. Generally, people who develop Alzheimer’s disease show signs of impaired eye mobility before any cognitive symptoms.
Participants in this study enter a “visual paradigm” in which they must listen to a series of sentences while looking at images on a computer screen. When what is said and the picture match, the participant must click the mouse.
An infrared camera directs a beam at the subject’s eyes, which tracks their eye movements. The camera records when people look at the screen and for how long, as well as the accuracy of each view fixation, the time spent analyzing the image, and how quickly you click.
“If we finally create a database of people with APP by tracking their eye movements as they process language, we will have a tool that can predict the development of aphasia in people with mild dementia. “, says Arslan.
Cerebral lesion – brain-damage
A separate part of the ProResA project focuses on magnetic resonance imaging (MRI) to identify areas of the brain that are not working properly. The team set out to create a map detailing brain damage and linking it to specific types of language impairment.
TIME is another European project using magnetic resonance imaging. Its director, Dr. Biondo, is dedicated to identifying areas and brain networks that cause time-related dysfunction.
Some aphasic people speak “telegraphically”, that is, by formulating sentences without verbs and which contain no temporal reference. “We communicate a lot with verbs. They are the core of the sentence and they convey essential information about time,” says Biondo. “However, when someone says ‘I’m having dinner,’ we don’t know if the action happened in the past, will happen in the future, or is happening right now.”
Very little is known about the causes of this phenomenon, but some believe that the problem is not simply linguistic, but that it responds to a difficulty in conceptualizing actions that do not occur at the time.
simple tasks
Biondo will ask patients to perform simple tasks — like sorting a series of photos of famous people by age — and matching the results with images of the brain that highlight the specific region where a lesion exists.
“When we know better what’s going on, we’ll try to help people in much more meaningful ways. For example, we can work on practical ways to train the brain to recover functions that have been lost.”
The research described in this article was financed by European funds. Article originally published in Horizonthe Journal of Research and Innovation of the European Union.
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