Stewart Christopher C, Griffith H Randall, Okonkwo Ozioma C, Martin Roy C, Knowlton Robert K, Richardson Elizabeth J, Hermann Bruce P, Seidenberg Michael
Department of Psychology, University of Alabama at Birmingham, Birmingham, USA.
Brain Cogn. 2009 Feb;69(1):65-72. doi: 10.1016/j.bandc.2008.05.005. Epub 2008 Jul 2.
Recent theories have posited that the hippocampus and thalamus serve distinct, yet related, roles in episodic memory. Whereas the hippocampus has been implicated in long-term memory encoding and storage, the thalamus, as a whole, has been implicated in the selection of items for subsequent encoding and the use of retrieval strategies. However, dissociating the memory impairment that occurs following thalamic injury as distinguished from that following hippocampal injury has proven difficult. This study examined relationships between MRI volumetric measures of the hippocampus and thalamus and their contributions to prose and rote verbal memory functioning in 18 patients with intractable temporal lobe epilepsy (TLE). Results revealed that bilateral hippocampal and thalamic volume independently predicted delayed prose verbal memory functioning. However, bilateral hippocampal, but not thalamic, volume predicted delayed rote verbal memory functioning. Follow-up analyses indicated that bilateral thalamic volume independently predicted immediate prose, but not immediate rote, verbal recall, whereas bilateral hippocampal volume was not associated with any of these immediate memory measures. These findings underscore the cognitive significance of thalamic atrophy in chronic TLE, demonstrating that hippocampal and thalamic volume make quantitatively, and perhaps qualitatively, distinct contributions to episodic memory functioning in TLE patients. They are also consistent with theories proposing that the hippocampus supports long-term memory encoding and storage, whereas the thalamus is implicated in the executive aspects of episodic memory.
最近的理论认为，海马体和丘脑在情景记忆中发挥着不同但相关的作用。海马体与长期记忆的编码和存储有关，而丘脑整体上与后续编码项目的选择和检索策略的使用有关。然而，区分丘脑损伤后出现的记忆障碍与海马体损伤后的记忆障碍已被证明是困难的。本研究调查了18例难治性颞叶癫痫（TLE）患者海马体和丘脑的MRI体积测量值之间的关系，以及它们对散文和机械言语记忆功能的贡献。结果显示，双侧海马体和丘脑体积独立预测延迟的散文言语记忆功能。然而，双侧海马体体积而非丘脑体积预测延迟的机械言语记忆功能。后续分析表明，双侧丘脑体积独立预测即时散文言语回忆，但不预测即时机械言语回忆，而双侧海马体体积与这些即时记忆测量指标均无关。这些发现强调了丘脑萎缩在慢性TLE中的认知意义，表明海马体和丘脑体积在数量上，甚至可能在质量上，对TLE患者的情景记忆功能有不同的贡献。它们也与提出海马体支持长期记忆编码和存储，而丘脑与情景记忆的执行方面有关的理论一致。
