A sensory explanation for visual attention deficits in the elderly.
BACKGROUND
Reduced visual attention has been implicated as a major factor in age-related deficits of real-world functioning such as driving. However, the contribution of sensory factors to visual attention deficits has not been delineated. The magnocellular stream, which is diminished in aging, provides the dominant input to attention, and could provide a direct visual sensory explanation for these attentional losses.


METHODS
We measured temporal response curves for transient visual attention in older and younger subjects. Attentional cues stimulated both the magnocellular and parvocellular streams.


RESULTS
Older subjects exhibited slower, weaker responses than younger subjects. The time course in younger subjects agreed with that obtained for magnocellular(M)-biased stimuli, whereas that of older subjects agreed with parvocellular(P)-biased responses.


CONCLUSIONS
The activation of transient visual attention is slower and weaker for elderly subjects, reflecting a reduced magnocellular input. This marks a primary visual cause for visual attention deficits of the elderly.
Steinman
S B
SB
Department of Ophthalmology, Washington University School of Medicine, St. Louis, Missouri.
Steinman
B A
BA
Trick
G L
GL
Lehmkuhle
S
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D003072:Cognition Disorders / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology; D014786:Vision Disorders / Q000503:physiopathology*; D014794:Visual Fields; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*