title: Effects of Alzheimer's Disease on Visual Target Detection: A "Peripheral Bias".
abstract: Visual exploration is an omnipresent activity in everyday life, and might represent an important determinant of visual attention deficits in patients with Alzheimer's Disease (AD). The present study aimed at investigating visual search performance in AD patients, in particular target detection in the far periphery, in daily living scenes. Eighteen AD patients and 20 healthy controls participated in the study. They were asked to freely explore a hemispherical screen, covering ±90°, and to respond to targets presented at 10°, 30°, and 50° eccentricity, while their eye movements were recorded. Compared to healthy controls, AD patients recognized less targets appearing in the center. No difference was found in target detection in the periphery. This pattern was confirmed by the fixation distribution analysis. These results show a neglect for the central part of the visual field for AD patients and provide new insights by mean of a search task involving a larger field of view.
authors: Gerontechnology and Rehabilitation Group, University of Bern Bern, Switzerland.
authors: Vanessa
authors: V
authors: Vallejo
authors: Gerontechnology and Rehabilitation Group, University of BernBern, Switzerland; ARTORG Center for Biomedical Engineering Research, University of BernBern, Switzerland.
authors: Dario
authors: D
authors: Cazzoli
authors: University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern Bern, Switzerland.
authors: Luca
authors: L
authors: Rampa
authors: Gerontechnology and Rehabilitation Group, University of Bern Bern, Switzerland.
authors: Giuseppe A
authors: GA
authors: Zito
authors: Gerontechnology and Rehabilitation Group, University of Bern Bern, Switzerland.
authors: Flurin
authors: F
authors: Feuerstein
authors: Gerontechnology and Rehabilitation Group, University of Bern Bern, Switzerland.
authors: Nicole
authors: N
authors: Gruber
authors: Gerontechnology and Rehabilitation Group, University of BernBern, Switzerland; Perception and Eye Movement Laboratory, Department of Neurology and Clinical Research, University Hospital Inselspital, University of BernBern, Switzerland.
authors: René M
authors: RM
authors: Müri
authors: Gerontechnology and Rehabilitation Group, University of BernBern, Switzerland; University Hospital of Old Age Psychiatry and Psychotherapy, University of BernBern, Switzerland; Private Hospital WyssMünchenbuchsee, Switzerland.
authors: Urs P
authors: UP
authors: Mosimann
authors: Gerontechnology and Rehabilitation Group, University of BernBern, Switzerland; ARTORG Center for Biomedical Engineering Research, University of BernBern, Switzerland.
authors: Tobias
authors: T
authors: Nef
keywords: Alzheimer’s disease; eye movements; large hemispherical screen; search strategy; target detection; visual attention; visual exploration