Visuoperceptual performances in aging and dementia: clinical and theoretical implications.

Spatial and nonspatial visuoperceptual abilities were assessed in normal older subjects (65-94 years of age) and in a sample of age-matched patients with various forms of dementia. Steady, moderate decline was evident with increasing age in normal subjects but severe visuoperceptual impairments occurred in many dementia patients, indicating that such assessment may be of benefit in the detection of abnormal mental decline. Dissociations in performance were frequent among dementia patients but not among normals, suggesting that dementia may be manifested in differential perceptual-cognitive decline.