title: Patients with Mild Alzheimer's Disease Fail When Using Their Working Memory: Evidence from the Eye Tracking Technique.
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.
authors.affiliation: Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina, Instituto de Investigaciones en Ingeniería Eléctrica (IIIE) (UNS-CONICET), Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Fernández
authors.affiliation: Institute of Cognitive Neurology (INECO), Buenos Aires, Argentina.
authors.forename: Facundo
authors.initials: F
authors.lastname: Manes
authors.affiliation: Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) (UNS-CONICET), Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Politi
authors.affiliation: Clínica Privada Bahiense, Bahía Blanca, Buenos Aires, Argentina.
authors.forename: David
authors.initials: D
authors.lastname: Orozco
authors.affiliation: Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina, Instituto de Investigaciones en Ingeniería Eléctrica (IIIE) (UNS-CONICET), Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Marcela
authors.initials: M
authors.lastname: Schumacher
authors.affiliation: Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina, Instituto de Investigaciones en Ingeniería Eléctrica (IIIE) (UNS-CONICET), Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Liliana
authors.initials: L
authors.lastname: Castro
authors.affiliation: Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina, Instituto de Investigaciones en Ingeniería Eléctrica (IIIE) (UNS-CONICET), Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Agamennoni
authors.affiliation: Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) (UNS-CONICET), Bahía Blanca, Buenos Aires, Argentina.
authors.forename: Nora P
authors.initials: NP
authors.lastname: Rotstein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology*; D008570:Memory, Short-Term / Q000502:physiology*; D011939:Mental Recall; D008609:Mental Status Schedule; D011237:Predictive Value of Tests; D012660:Semantics; D014706:Verbal Learning / Q000502:physiology
keywords: Alzheimer’s disease; eye movements; memory; reading