Patients with Mild Alzheimer’s Disease Fail When Using Their Working Memory: Evidence from the Eye Tracking Technique.
|Autores||Gerardo Fernandez, Facundo Manes, Luis E. Politi, David Orozco, Marcela Schumacher, Liliana Castro, Osvaldo Agamennoni, Nora P. Rotstein.|
|Journal||J Alzheimers Dis|
|Volumen||2016 Jan 13;50(3):827-38. doi: 10.3233|
|Abstract||Patients with Alzheimer’s disease (AD) develop progressive language, visuoperceptual, attentional, and oculomotor changes that can have an impact on their reading comprehension. However, few studies have examined reading behavior in AD, and none have examined the contribution of predictive cueing in reading performance. For this purpose we analyzed the eye movement behavior of 35 healthy readers (Controls) and 35 patients with probable AD during reading of regular and high-predictable sentences. The cloze predictability of words N - 1, and N + 1 exerted an influence on the reader’s gaze duration. The predictabilities of preceding words in high-predictable sentences served as task-appropriate cues that were used by Control readers. In contrast, these effects were not present in AD patients. In Controls, changes in predictability significantly affected fixation duration along the sentence; noteworthy, these changes did not affect fixation durations in AD patients. Hence, only in healthy readers did predictability of upcoming words influence fixation durations via memory retrieval. Our results suggest that Controls used stored information of familiar texts for enhancing their reading performance and imply that contextual-word predictability, whose processing is proposed to require memory retrieval, only affected reading behavior in healthy subjects. In AD patients, this loss reveals impairments in brain areas such as those corresponding to working memory and memory retrieval. These findings might be relevant for expanding the options for the early detection and monitoring in the early stages of AD. Furthermore, evaluation of eye movements during reading could provide a new tool for measuring drug impact on patients’ behavior.|
|Resumen||Los pacientes con enfermedad de Alzheimer desarrollan cambios progresivos en el lenguaje, percepción visual, atención, y cambios oculomotores que pueden tener un impacto en la comprensión de la lectura. En esta investigación evaluamos con tecnología de seguimiento ocular a pacientes con Enfermedad de Alzheimer durante la lectura y sugerimos esta tecnica como una posible nueva herramienta para sumar a las opciones diagnosticas y de seguimiento en las primeras etapas de la enfermedad.|