Summary and conclusions

Elderly subjects perform worse than young persons on virtually all cognitive and behavioral functions that are tested. Thus, performance decrements in intellectual functions, memory, perception, behavioral organization and motor functions have been noted. However, elderly people are not inferior in tasks in which they can rely on well-established skills and knowledge. With respect to AD, the pattern of cognitive deficits seems to be similar to that seen in 'normal' aging but the dementing...

Neuropathology of Alzheimers disease

In Alzheimer's disease, there is an additive significant loss of brain tissue, and this involves both neocortex and cerebral white matter, septum, amygdaloid, and hippocampus. The weight loss, however, does not regress as a function of age, with which there is no correlation. Brain weight correlates significantly with the concentration of plaques in the neocortex if normals are included. Counting neuroectodermal cells in three areas of the neocortex revealed population changes which are...

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Precentral and dorsolateral prefrontal cortex, hip-pocampal formation and cerebellum in seven cases of DS between ages 6 and 64 years. No changes pertinent to the cognitive and motor impairments of DS were evident. For example, in our younger cases of DS we did not find striking alterations of the morphology of dendritic spines, or apparent reduction in the numbers of dendrites or dendritic spines of neocortical pyramids at a qualitative level. This is at variance with some published reports...

Cognitive functions in aging and dementia

Several experimental paradigms have been used to study perception in the aged, and the results, generally, point in the same direction. The effect of sensory stimulation seems to persist longer in the central nervous system (CNS) of the aged subject, leading to a less efficient response to subsequent stimulation. This notion evolved from experiments, which started in the forties, with the so-called 'critical flicker fusion' technique a brief (e.g. 20 ms) light stimulus was presented,...

The neuropsychology of aging and dementia

Similarities and differences between aging and AD Neuropsychological research in aging and dementia has primarily focussed on memory processes although it is obvious that other cognitive functions are impaired as well. The quantity of research on memory may thus give the wrong impression that memory is the major function involved. There is an obvious need for further studies of information processing, language, perception and planning organization coding processes. There exists a parallel with...