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Richard Mayeux

Publications and source records attributed to Richard Mayeux.

57 records · Page 4Linked to original sources
PubMed2002

Imaging hippocampal function across the human life span: is memory decline normal or not?

Memory function commonly declines in later life. Whether memory decline represents a disease process or whether it is part of normal aging remains unknown. Here we answer this question by assessing the function of multiple subregions that make up the hippocampal circuit across the human life span. A newly developed MRI approach--designed to detect functional changes in individual hippocampal subregions--was used to assess the hippocampal circuit in 70 subjects between 20 and 88 years of age. Using strict parametric criteria, analysis revealed that function in two hippocampal subregions--the subiculum and the dentate gyrus--decline normally with age. In contrast, function in the entorhinal cortex declines pathologically. Single-subject analysis revealed that hippocampal dysfunction, found in 60% of elders was selectively correlated with memory decline. These results show that memory decline is caused by different mechanisms and suggests how memory decline should be approached clinically.

Adult↗
PubMedDate not supplied

Acquisition, recall, and forgetting of verbal information in long-term memory by young, middle-aged, and elderly individuals.

Memory performance by four age groups (30-45 years, 46-60 years, 61-75 years, and 76-90 years) was compared on a multi-trial verbal recall task with 20-minute and 1-day delay free recall and recognition trials. The rate of acquisition across 5 learning trials was similar for all ages except the youngest group whose performance was constrained by a ceiling effect. The level of acquisition achieved was less in the two oldest groups. Words gained across trials and words lost across trials made similar contributions to the shape of the learning curve for the acquisition trials. Subjective organization decreased with age, but remained strongly related to the number of words recalled during acquisition for all age groups. The two oldest age groups demonstrated significant declines in words recalled on the 20-minute and 1-day delay trials. A subset of the oldest group demonstrated more rapid forgetting at the 1-day delay when participants from all age conditions were matched on acquisition. Thus, many aspects of free recall were impaired with age, and variance measurement of recall showed greater inter-individual differences with increasing age. This increase in individual differences could reflect a single form of age-related memory impairment, or it could indicate that memory impairment in the elderly is due to multiple processes. The importance of testing across the life span and using tests that examine a variety of memory components and processes for establishing norms and clarifying age-related deficits are discussed.

Adult↗