Krembil Neuroscience Centre, Toronto Western Hospital, UHN, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Ontario, Canada; Rotman Research Institute at Baycrest Center for Geriatric Care, Toronto, Ontario, Canada.
Hippocampus. 2014 May;24(5):560-76. doi: 10.1002/hipo.22249. Epub 2014 Feb 10.
Perceptual richness, a defining feature of episodic memory, emerges from the reliving of multimodal sensory experiences. Although the importance of the medial temporal lobe (MTL) to episodic memory retrieval is well documented, the features that determine its engagement are not well characterized. The current study assessed the relationship between MTL function and episodic memory's perceptual richness. We designed a laboratory memory task meant to capture the complexity of memory for life episodes, while manipulating memory's perceptual content. Participants encoded laboratory episodes with rich (film clips) and impoverished (written narratives) perceptual content that were matched for other characteristics such as personal significance, emotionality and story content. At retrieval, participants were probed to describe the stories' perceptual features and storyline. Participants also recalled autobiographical memories (AMs) in a comparison condition. We compared the performance of patients with unilateral medial temporal lobe epilepsy (mTLE) and healthy controls to assess how damage to the MTL affects retrieval in these conditions. We observed an overall decrease in detail count in the mTLE group, along with a disproportionate deficit in perceptual details that was most acute in the AM and the perceptually enriched film clip conditions. Our results suggest that the impaired sense of reliving the past that accompanies MTL insult is mediated by a paucity of perceptual episodic memory details. We also introduce a new protocol that successfully mimics naturalistic memories while benefiting from the experimental control provided by using laboratory stimuli.
知觉丰富度是情景记忆的一个定义特征，源于多模态感官体验的再体验。虽然内侧颞叶（MTL）对情景记忆检索的重要性已有充分记录，但决定其参与的特征尚未得到很好的描述。本研究评估了 MTL 功能与情景记忆知觉丰富度之间的关系。我们设计了一个实验室记忆任务，旨在捕捉生活事件记忆的复杂性，同时操纵记忆的知觉内容。参与者用丰富的（电影片段）和贫乏的（书面叙述）知觉内容编码实验室场景，这些内容在个人意义、情感和故事情节等方面是匹配的。在检索时，参与者被要求描述故事的知觉特征和故事情节。参与者还在比较条件下回忆自传记忆（AMs）。我们比较了单侧内侧颞叶癫痫（mTLE）患者和健康对照组的表现，以评估 MTL 损伤如何影响这些条件下的检索。我们观察到 mTLE 组的详细信息计数总体减少，以及在 AM 和知觉丰富的电影片段条件下，知觉细节的不成比例缺陷最为明显。我们的结果表明，伴随 MTL 损伤的过去再体验能力受损是由知觉情景记忆细节不足介导的。我们还引入了一种新的方案，该方案成功地模拟了自然记忆，同时受益于使用实验室刺激提供的实验控制。
