正常老年人无意义图形记忆任务的fMRI研究

Memory tasks in normal aged volunteers:an fMRI study

目的 探讨正常老年人进行记忆任务的实验可行性及激活脑区。方法 对 11例正常老年志愿者进行无意义图形记忆任务的fMRI实验 ,实验以组块方式设计 ,包括第一次记忆组、重复记忆组和再认组。实验数据以SPM 99作后处理显示激活脑区。结果 10例受试者的记忆任务完成较好 ,记忆和再认的激活区域主要集中双侧前额叶、双侧海马旁回(左侧为主 )、右侧海马、双侧顶叶 (主要为顶上小叶和楔前叶 )。记忆编码时海马的激活集中在海马头部 ,而提取时海马的激活则集中在海马的体部及尾部。结论 老年人进行fMRI认知实验具有可行性 ,记忆的编码和提取时需要内侧颞叶海马系统的参与 ,但所倚重的脑区有微小的差别。

Objective To investigate the feasibility and cortex activation of fMRI in the aged volunteers during the performance of memory tasks. Methods Memory tasks including encoding and retrieval of nonsense line drawings were conducted in 11 normal aged volunteers. The fMRI data was processed using SPM99 to reveal the activated cortex. Results The memory tasks were fulfilled satisfactorily in 10 aged subjects. Cortex in the bilateral dorsal lateral frontal lobes,bilateral parahippocampus,right hippocampus and bilateral parietal lobes showed activation. The head of right hippocampus showed activation during the encoding phase whereas the body and the tail of the hippocampus showed activation during the retrieval phase. Conclusion fMRI cognitive tasks are feasible in the aged people. The medial temporal lobe takes part in the encoding and retrieval processes,but the cortex involved in the two processes are different.