title: Diminished top-down control underlies a visual imagery deficit in normal aging.
abstract: Mental imagery is involved in a wide variety of cognitive abilities, including reasoning, spatial navigation, and memory. Cognitive aging is associated with impairments in these abilities, suggesting that diminished fidelity of mental images in older adults may be related to diverse cognitive deficits. However, an age-related deficit in mental imagery and its role in memory impairment is still a matter of debate. Previous human fMRI studies demonstrated that visual imagery activates representations in category-selective visual cortex via top-down control mechanisms. Here, we use fMRI to show that normal aging is associated with diminished selectivity of visual cortex activation during visual imagery, with a corresponding reduction in the selectivity of functional connections between prefrontal cortex and visual cortices. Moreover, a relationship between reduced imagery selectivity and visual memory in older adults was established. These results reveal that aging disrupts neural networks that subserve mental imagery and offers evidence of this as a factor in age-related memory decline.
authors: WM Keck Center For Integrative Neurosciences, Department of Neurology, University of California, San Francisco, San Francisco, California 94158-2240, USA.
authors: Jonathan
authors: J
authors: Kalkstein
authors: Kristen
authors: K
authors: Checksfield
authors: Jacob
authors: J
authors: Bollinger
authors: Adam
authors: A
authors: Gazzaley
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014795:Visual Pathways / Q000098:blood supply / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen