2ND MULTIDISCIPLINARY NEURODEGENERATION CONGRESS, İstanbul, Turkey, 6 - 07 November 2020, pp.18
Using Eye Movement Tracking to Detect Comprehension Deficits in Neurodegenerative Aphasia.
Asst. Prof. Dr. Mustafa Seçkin- Acıbadem Mehmet Ali Aydınlar University Faculty of Medicine,Department of Neurology
Aphasia caused by neurodegenerative diseases progress slowly and early stages of comprehension impairment in neurodegenerative aphasia may be undetectable using traditional tests. A new and sensitive method known as eye movement tracking provides an excellent opportunity to examine comprehension deficits in patients even at the early stages of progressive aphasia. In the current clinical setting, failure in word-to-object matching tasks would be regarded as evidence indicating single word comprehension deficits. However, the majority of these tasks are designed as pencil and paper tests and patients with prominent impairment in these tasks already have significant atrophy in language areas. On the other hand, eye movements during a word-to-object matching task can be used as probes of lexicosemantic associations for an on-line assessment of the dynamic search of stored semantic representations. Therefore, impairment in lexico-semantic associations may be evident in effortful visual search characterized by back and forth fixations between the target and distractors even in trials where the target is eventually recognized. In other words, a correct response will not mask underlying impairment as eye movements reveal uncertainty that precedes more severe disruption of the linkage between words and their semantic representations. Eye tracking may also help understand the mechanisms of dissociation between single-word and sentence comprehension deficits which is critical for distinguishing semantic aphasia from agrammatic aphasia