Why Is Time Expression Harder for Aphasia Patients?

Time lost in translation: New study reveals how aphasia patients face unique language-specific hurdles in expressing past and future events.

Highlights:

Aphasia patients struggle with encoding or retrieval of verb tenses, and the difficulty depends on their language structure
Greek and Italian speakers face encoding challenges, while Russian and English speakers struggle more with retrieval
These findings can improve targeted therapy and diagnosis by accounting for language-specific differences in aphasia

The causes of aphasia patients' difficulties expressing grammatical tense have been discovered by an international team of researchers, including scientists from the HSE Centre for Language and Brain. They discovered that people with speech impairments had difficulty developing the idea of time and choosing the appropriate verb tense. However, whether these processes are more difficult depends on the speaker's language. The findings were reported in the journal Aphasiology ().

Aphasia
Aphasia is a condition where the patient has a language disorder. The patient has problems with comprehension, expression, repetition, reading and writing.

‘Did you know?
Aphasia patients in different countries experience unique challenges based on their language structure. A new study decodes how aphasia impacts expressing time! Language-specific challenges with encoding & retrieval offer insights for better therapies. #aphasiaresearch #medindia’

What is Aphasia?

Aphasia is a severe speech condition that commonly follows a stroke and causes people to lose their ability to talk clearly. This might present itself in the erroneous use of verb tenses, making it difficult for patients to discuss past or future occurrences and severely affecting daily communication.

Acquired Epileptiform Aphasia
Acquired Epileptiform Aphasia or Landau –Kleffner Syndrome (LKS) is a rare childhood disorder in which children have language and behavioral problems.

Decoding Tense Expression: Insights from Multilingual Aphasia Research

To study the causes of these issues, researchers from universities in Russia, Greece, Italy, the United States, and Norway undertook an experiment. They proposed that tense expression deficiencies could result from two separate processes: encoding and retrieval. During encoding, a speaker develops the idea of time. During retrieval, they choose the appropriate verb form to express the thought. To determine the influence of each step, the scientists conducted studies with aphasia patients who spoke four distinct languages: Greek, Russian, Italian, and English. These languages were chosen because they have varied verb tense structures, allowing the researchers to investigate how language-specific aspects affect tense encoding and retrieval in aphasia patients.

To aid with diagnosis, the researchers created two sentence completion tasks. The first task asked participants to fill in blanks in sentences, which required both encoding and retrieval. They had to complete the sentence using the model, taking into account the change in the tense form of the verb. For example: "The gardener watered the flowers yesterday." Tomorrow, the gardener will... the flowers." The second challenge asked participants to finish phrases without modifying the verb tense. They were given the phrase 'to water the plants' and heard the example sentence 'The gardener is currently harvesting mushrooms.' They were then encouraged to begin a sentence with 'The gardener is now...' and conclude it with the term 'watering the plants' in the proper form, resulting in 'is watering the plants'.

Study: Strengthen Speech Networks to Treat Aphasia
For both the victims and their loved ones, aphasia, an impairment in speaking and understanding language after a stroke, is frustrating.

Revealing Language-Specific Challenges in Encoding and Retrieval

By comparing the results of these tests, the researchers were able to determine whether the fundamental issues occurred during encoding or retrieval.

The study found that the majority of individuals had deficits in both encoding and retrieval, but the severity of these problems varied based on the language and the individual. For example, Russian and English-speaking individuals suffered more with the retrieval task, whereas Greek and Italian-speaking participants struggled mostly with encoding. Interestingly, the challenges in describing time were selective. Some individuals had difficulty recalling the past, while others struggled with the future.

Post-Stroke Aphasia Recovery Hindered by Shift of Language Function to Right Hemisphere
A compensatory reorganization of language function to right hemispheric brain regions bodes poorly for language recovery among stroke patients, researchers have found.

Advancing Neurorehabilitation: Language-Specific Therapies for Aphasia

These findings are significant for understanding how aphasia patients lose the ability to describe time differently, depending on the features of their language. According to Olga Buivolova, Research Fellow at the HSE Centre for Language and Brain and one of the study's authors, "We can now better assess which components of time present the most difficulty for patients and begin designing more targeted therapy methods."

As experts point out, the study's major findings may have practical consequences for neurorehabilitation. For starters, this experimental method can aid in determining the root reasons for issues with verb tenses. This means that speech therapists and neuropsychologists will be able to work more closely and effectively with patients in speech rehabilitation.

Second, the study contributes to a better understanding of how linguistic disparities influence aphasia symptoms. This is critical for designing standardized tests and techniques that take into account the characteristics of a speaker's local language, resulting in a more accurate and comprehensive diagnosis of aphasia.

Reference:

Teasing apart time reference-related encoding and retrieval deficits in aphasia: evidence from Greek, Russian, Italian and English - (https://www.tandfonline.com/doi/full/10.1080/02687038.2024.2415927)

Source-Medindia