Top-down and bottom-up sources of eye-movement guidance during realistic scene search in Alzheimer's disease.

Objective: Visual search is a crucial task in daily life, but in Alzheimer's disease (AD) it has usually been investigated using simple arrays. Here, we used scenes depicting real environments and studied the time course of attentional guidance.

Method: We analyzed eye-movement differences between mild AD patients and age-matched healthy controls during search.

Age-related differences when searching in a real environment: The use of semantic contextual guidance and incidental object encoding.

Visual search is a crucial, everyday activity that declines with ageing. Here, referring to the environmental support account, we hypothesised that semantic contextual associations between the target and the neighbouring objects (e.g.

Top-down and bottom-up guidance in normal aging during scene search.

Age-related differences in visual search have been extensively studied using simple item arrays, showing an attentional decline. Little is known about how aging affects attentional guidance during search in more complex scenes. To study this issue, we analyzed eye-movement behavior in realistic scene search.

A compressibility account of the color-sharing bonus in working memory.

It has been established that objects sharing color in a visual display can boost working memory. The capacity to encode singletons particularly benefits from the repetition of colors encoded as perceptual groups. We manipulated the algorithmic complexity of visual displays to test whether compressibility of information could account for the color-sharing bonus.

Alzheimer's Disease, Visual Search, and Instrumental Activities of Daily Living: A Review and a New Perspective on Attention and Eye Movements.

Many instrumental activities of daily living (IADLs), like cooking and managing finances and medications, involve finding efficiently and in a timely manner one or several objects within complex environments. They may thus be disrupted by visual search deficits. These deficits, present in Alzheimer's disease (AD) from its early stages, arise from impairments in multiple attentional and memory mechanisms.