Article

To what extent does our visual-spatial attention change with age? In this regard,
it has been previously reported that relative to young controls, seniors show
delays in attention-related sensory facilitation.
Given this finding, our study
was designed to examine two key questions regarding age-related changes in the
effect of spatial attention on sensory-evoked responses in visual cortex--are
there visual field differences in the age-related impairments in sensory
processing, and do these impairments co-occur with changes in the executive
control signals associated with visual spatial orienting? Therefore, our study
examined both attentional control and attentional facilitation in seniors (aged
66-74 years) and young adults (aged 18-25 years) using a canonical spatial
orienting task. Participants responded to attended and unattended peripheral
targets while we recorded event-related potentials (ERPs) to both targets and
attention-directing spatial cues. We found that not only were sensory-evoked
responses delayed in seniors specifically for unattended events in the left
visual field as measured via latency shifts in the lateral occipital P1 elicited
by visual targets, but seniors also showed amplitude reductions in the anterior
directing attentional negativity (ADAN) component elicited by cues directing
attention to the left visual field. At the same time, seniors also had
significantly higher error rates for targets presented in the left vs. right
visual field. Taken together,
our data thus converge on the conclusion that
age-related changes in visual spatial attention involve both sensory-level and
executive attentional control processes, and that these effects appear to be
strongly associated with the left visual field.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS