Medial temporal lobe contributions to short-term memory in amnesia

描述(申请人提供)：大量证据表明，内侧颞叶(MTL)在长时记忆(LTM)中起关键作用，但在短期记忆(STM)中几乎没有作用。然而，最近的数据对MTL功能的这种标准观点提出了挑战，证明了(1)当信息短时间延迟保存在记忆中时，MTL的活动，以及(2)有MTL损害的健忘症患者的STM损害。在LTM中，MTL的一个关键功能是将不同的体验元素绑定到一个统一的记忆中，这样一来，项目以后就可以通过它们的上下文关联(情节记忆)来记住。一种可能性是，MTL的关系绑定功能超出了LTM域，也支持STM。这项应用中的实验使用神经成像和神经心理学相结合的方法，在一组MTL受损的健忘症患者和一组神经功能正常的对照组中测试这一假设。神经心理学实验考察了(1)MTL损伤是否在多个表征水平上选择性地干扰了关系STM；(2)MTL损伤是否损害了STM中跨事件整合以支持概括的能力。如果健忘症患者表现出相关STM和泛化的损害，这将反对STM和LTM之间的传统神经解剖学差异，并将为MTL在记忆中的作用提供重要的新见解。[为了补充这种神经心理学方法，神经成像程序提供了对健忘症神经病理的全面评估，这超出了标准的病变体积分析。白质结构完整性(扩散张量成像)和神经元功能(功能磁共振成像)的测量将被收集，以更好地表征可能伴随着健忘症MTL损伤的局部和网络中断。通过共同解决健忘症中认知和神经障碍的问题，这项应用中的实验将为这两个领域之间的关系提供更多的见解。]将神经病理学的具体措施与行为联系起来，将澄清MTL对STM的贡献，并促进对MTL功能的机械论解释以及对STM的理论解释。由于记忆障碍在神经疾病和疾病患者中很常见，对这些障碍的性质及其神经基础的更好了解将为减轻此类疾病的负担提供新的策略。

DESCRIPTION (provided by applicant): A large body of evidence suggests that the medial temporal lobes (MTL) play a critical role in long-term memory (LTM) but little or no role in short-term memory (STM). However, recent data have challenged this standard view of MTL function by demonstrating (1) activity in the MTL when information is held in memory over short delays and (2) STM impairments in amnesic patients with MTL damage. A key function of the MTL in LTM is to bind distinct elements of experience into a unified memory so that items can later be remembered with their contextual associations (episodic memory). One possibility is that the relational binding function of the MTL extends beyond the LTM domain to support STM as well. The experiments in this application use a combined neuroimaging and neuropsychological approach to test this hypothesis in a group of amnesic patients with MTL damage and a comparison group of neurologically intact controls. The neuropsychological experiments investigate (1) whether MTL damage selectively interferes with relational STM at multiple levels of representation and (2) whether MTL damage impairs the ability to integrate across events in STM to support generalization. If amnesic patients demonstrate impairments in relational STM and generalization, this would argue against traditional neuroanatomical distinctions between STM and LTM and would provide important new insight into the role of the MTL in memory. [To compliment this neuropsychological approach, the neuroimaging procedures provide a comprehensive assessment of the neuropathology in amnesia that goes beyond standard lesion volumetric analyses. Measures of both white matter structural integrity (diffusion tensor imaging) and neuronal function (functional magnetic resonance imaging) will be collected to better characterize the local and network disruptions that may accompany damage to the MTL in amnesia. By jointly addressing questions of both cognitive and neural disruptions in amnesia, the experiments in this application will provide greater insights into the relationship between these two domains.] Linking specific measures of neuropathology to behavior will clarify the contributions of the MTL to STM and advance both mechanistic accounts of MTL function as well as theoretical accounts of STM. Because memory impairments are common in patients with neurological disorders and disease, a greater understanding of the nature of these impairments and their neural substrates will inform new strategies for reducing the burden of such illnesses.