Background: Visual attentional performance is affected by aging, but there are methodological barriers to the understanding of this phenomenon that are due, above all, to the concomitant deterioration of sensory or central factors such as visual acuity and information processing speed.
Objective: The aim of the present study was to verify the effects of aging on visual attentional focusing by analyzing the space- and object-based components as well as the exogenous and endogenous dimensions of the attentional allocation.
Methods: Focusing of visual attention was investigated in 14 youngsters, 14 younger adults and 14 older adults (age ranges 12-15, 24-38 and 60-75 years, respectively). In two discrimination reaction time (RT) experiments, attention was cued by means of spatial cues of different size followed by compound stimuli at a shorter (150 ms) and a longer (500 ms) stimulus-onset asynchrony (SOA). The compound stimuli contained a predefined target letter at a local or global level.
Results: Older adults showed generally slower RTs and higher rates of delayed responses than younger individuals and reduced discrimination speed of local objects at 150-ms SOA, particularly when attention was invalidly cued to focus at a larger spatial scale.
Conclusions: This pattern of results suggests that aging causes a dysfunction of the space-based and the object-based components of the attentional 'zooming in'. Such information may be of practical relevance for developing attentional training programs for older adults.
Copyright (c) 2005 S. Karger AG, Basel.