Distinguishing attentional gain and tuning in young and older adults
Document Type
Article
Publication Date
1-1-2014
Journal
Neurobiology of Aging
Volume
35
Issue
11
First Page
2514
Last Page
2525
URL with Digital Object Identifier
10.1016/j.neurobiolaging.2014.04.028
Abstract
© 2014 Elsevier Inc. Here we examined with functional magnetic resonance imaging (fMRI) whether advanced age affects 2 mechanisms of attention that are widely thought to enhance signal processing in the sensory neocortex: gain and tuning. Healthy young and older adults discriminated faces under varying levels of object competition while fMRI was acquired. In young adults, cortical response magnitude to attended faces was maintained despite increasing competition, consistent with gain. Cortical response selectivity, indexed from repetition suppression, also increased only for attended faces despite increasing competition, consistent with tuning. Older adults exhibited intact gain, but altered tuning, with extrastriate cortical tuning determined by object salience rather than attention. Moreover, the magnitude of this susceptibility to stimulus-driven processing was associated with a redistribution of attention-driven competitive processes to the frontal cortices. These data indicate that although both gain and tuning are modulated by increased perceptual competition, they are functionally dissociable in the extrastriate cortices, exhibit differential susceptibility to advanced aging, and spare the frontal cortices a considerable processing burden through early selection.
Notes
This article is paywalled, please seek access through your institution's library