دانلود رایگان مقاله اثرات دارای هم پوشانی سن بر روی حافظه انجمنی و هیپوکامپ قدامی

ABSTRACT

The anterior hippocampus has been implicated in associative memory, and along with hippocampal volume, this type of memory declines with age. However, few cross-sectional studies include middle-aged samples, making it unclear at what point these age-related changes occur. In addition, although men and women have been shown to differ in associative memory and rates of age-related hippocampal atrophy, sex-differences in aging are rarely studied. To address these issues, we assessed memory for word-pairs, hippocampal volume and activation during encoding and retrieval, across middle-aged (n = 39) and older (n = 44) participants, specifically in relation to sex. Older adults showed significantly poorer associative memory compared to middle-aged adults, paralleled by smaller anterior hippocampi and less activation during successful retrieval. The age-by-sex interaction observed in memory performance was also mirrored in the volume and activation of the hippocampus, indicating more pronounced age-effects in men as compared to women. These results indicate a specific role of the anterior hippocampus in verbal associative memory and suggest they both decline between middle-age and older age.

4. Discussion

The aim of the present study was to assess associative memory and hippocampal integrity in older as compared to middle-aged adults, providing information on age-related impairments not available in previous research due to the dominating focus on comparisons between young and older groups. In addition, we specifically assessed if age-effects in associative memory and hippocampal volume and function are equal in men and women, or if sex acts as a modifying variable. Overall, our results demonstrate a link between associative memory and the anterior hippocampus, with age-related memory differences mirrored by smaller anterior hippocampal volumes and less task-related activation.As such,the hippocampus reflected the age-by-sex interaction observed in memory performance, indicating greater age-related effects in men as compared to women. However, it is necessary to further evaluate this interaction, taking specific aspects of the behavioral results into consideration.