Neuroscience Research Australia, Barker Street, Randwick, Sydney, Australia.
Neuropsychologia. 2011 Jul;49(9):2694-702. doi: 10.1016/j.neuropsychologia.2011.05.017. Epub 2011 May 30.
Episodic autobiographical memory (ABM) comprises recollection for events that are grounded within a specific spatiotemporal context, and usually accompanied by perceptual and emotional information. The neural substrates mediating ABM retrieval are those harbouring significant pathology in semantic dementia (SD) and behavioural-variant frontotemporal dementia (bvFTD), the most common subtypes of FTD. Relatively little is known, however, regarding the differential patterns of contextual details during episodic ABM retrieval across these dementia syndromes. This study investigated episodic ABM retrieval under free and probed recall conditions from 4 time periods with the aim to identify disease-specific profiles of episodic ABM contextual details. Episodic ABM was measured in 25 SD and 15 bvFTD patients and their performance contrasted to that of 17 Alzheimer's disease (AD) patients and 19 age-matched controls. Critically, SD patients showed relatively preserved recent ABM in comparison with remote epochs. In contrast, bvFTD and AD patients showed a reduced capacity to recall specific and contextually rich ABMs across all life epochs, in both free and probed recall conditions. Analyses of the recent period (last 12 months) provided evidence for different profiles of contextual episodic details recalled in dementia syndromes. Following probing, SD patients' recall deficits emanated exclusively from compromised Emotion/Thoughts and Spatiotemporal details. In contrast, bvFTD patients were significantly impaired across all categories of contextual details whereas AD patients showed deficits for Event and Emotion/Thoughts details only. As the largest study of ABM in FTD to date, these findings emphasise the differential impairment of recent ABM contextual details contingent on the underlying disease pathology. In addition, these results point towards the importance of investigating the constituent elements of emotion processing and strategic retrieval processes as potential variables mediating recent episodic ABM retrieval.
情景自传体记忆（ABM）包括对特定时空背景下发生的事件的回忆，通常伴有感知和情感信息。介导 ABM 检索的神经基质存在于语义痴呆症（SD）和行为变异额颞叶痴呆症（bvFTD）中，这是 FTD 最常见的亚型。然而，关于这些痴呆综合征在情景 ABM 检索过程中上下文细节的差异模式，我们知之甚少。本研究在自由和探测回忆条件下，从 4 个时间段研究情景 ABM 检索，旨在确定情景 ABM 上下文细节的疾病特异性特征。情景 ABM 在 25 名 SD 患者和 15 名 bvFTD 患者中进行测量，并将其表现与 17 名阿尔茨海默病（AD）患者和 19 名年龄匹配的对照组进行对比。重要的是，与远程时期相比，SD 患者的近期 ABM 相对保留。相比之下，bvFTD 和 AD 患者在自由和探测回忆条件下，在所有生命时期都表现出回忆特定和内容丰富的 ABM 的能力下降。对近期时期（过去 12 个月）的分析提供了证据，表明在痴呆综合征中回忆的情景细节存在不同的特征。在探测后，SD 患者的回忆缺陷仅源于情感/思想和时空细节受损。相比之下，bvFTD 患者在所有上下文细节类别中均受到严重损害，而 AD 患者仅在事件和情感/思想细节方面存在缺陷。作为迄今为止对 FTD 中 ABM 的最大研究，这些发现强调了基于潜在疾病病理学的最近 ABM 上下文细节的差异损伤。此外，这些结果表明，研究情绪处理和策略检索过程的组成要素作为潜在变量来调节最近的情景 ABM 检索非常重要。
