Interactions of sentence processing and attention allocation in people with aphasia

Principal Investigator: Tamás Káldi

Languages enable speakers to express what is important or new via certain structural or prosodic means. For example, in the sentence “It is Carl who likes fish” the important piece of information is that the individual at hand is Carl, whereas in the sentence “It is fish that Carl likes” the important bit is the type of food. This part of the sentence is called the Focus. Focus is an extremely important feature of language, as it enables the communicators to be efficient and to create coherent discourse.

Earlier research has shown that Focus fulfills this function by directing the attention of the listener: focused elements receive more attention, they are recognized more easily, and they are better remembered. Thus, it seems that attention has a special role in linguistic functioning. An intact attentional capacity is crucial for (efficient) language use.

Our research concentrates on how Focus directs the attention in people with post-stroke aphasia (PWA). Aphasia is an acquired language disorder, most commonly occurring after stroke. It is believed that this symptom complex does not arise solely from the decline in linguistic competence but also from a deterioration of the cognitive functions that underlie linguistic capabilities. One such capability is attention. Our research is motivated by the fact that the effect of focus on attention allocation has not been investigated in PWA thus far.

In our research we utilize eye tracking and pupillometry, which are efficient tools in investigating the relationship of attention allocation and linguistic functions during processing and production.

The research project involves three large scale experiments. The experiments address the question of how Focus directs the attention of PWA during: i) sentence processing, ii) memory maintenance of the Focused element and iii) sentence production. We hope that the results facilitate a deeper understanding of aphasia and contribute to the development of new approaches for state-of-the-art assessment, diagnostic, and therapeutic methods. The project can be found on NKFI’s page.