Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, UK.
Neuropsychologia. 2011 Nov;49(13):3620-8. doi: 10.1016/j.neuropsychologia.2011.09.015. Epub 2011 Sep 22.
Deficits in recalling the past and imagining fictitious and future scenarios have been documented in patients with hippocampal damage and amnesia that was acquired in adulthood. By contrast patients with very early hippocampal damage and developmental amnesia are not impaired relative to control participants when imagining fictitious/future experiences. Recently, however, a patient (HC) with developmental amnesia, resulting from bilateral hippocampal atrophy, was reported to be impaired, thus raising a question about the true nature of event construction in the context of developmental amnesia. Here, we assessed HC on a test of imagination which explored her ability to construct fictitious events or personal plausible future events. Her scenario descriptions were analysed in detail along a range of parameters, using two different scoring methods. HC's performance was comparable to matched control participants on all measures relating to the imagination of fictitious and future scenarios. We then considered why she was reported as impaired in the previous study. We conclude that various features of the previous testing methodology may have contributed to the underestimation of HC's ability in that instance. Patients like HC with developmental amnesia may be successful at future-thinking tasks because their performance is not based on true visualisation or scene construction supported by the hippocampus, but rather on preserved world knowledge and semantic representations.
在成年获得海马损伤和健忘症的患者中，已经记录到回忆过去和想象虚构和未来场景的缺陷。相比之下，具有非常早期海马损伤和发育性健忘症的患者在想象虚构/未来经历时相对于对照组没有受损。然而，最近，据报道，一名（HC）由于双侧海马萎缩而患有发育性健忘症的患者受损，从而引发了一个关于在发育性健忘症背景下事件构建的真实性质的问题。在这里，我们在一项想象力测试中评估了 HC，该测试探索了她构建虚构事件或个人合理未来事件的能力。我们使用两种不同的评分方法，详细分析了她的场景描述的一系列参数。HC 在所有与虚构和未来场景的想象相关的测量上的表现与匹配的对照组参与者相当。然后，我们考虑了为什么她在之前的研究中被报告为受损。我们的结论是，以前测试方法的各种特征可能导致了对 HC 在该情况下的能力的低估。像 HC 这样患有发育性健忘症的患者可能在未来思维任务中表现出色，因为他们的表现不是基于海马支持的真实可视化或场景构建，而是基于保留的世界知识和语义表示。
