Neuroscience Research Australia, Barker Street, Randwick, Sydney, NSW 2031, Australia.
Nat Rev Neurol. 2012 Feb 14;8(3):152-61. doi: 10.1038/nrneurol.2012.11.
Converging evidence suggests that when individuals are left to think to themselves, a so-called default network of the brain is engaged, allowing the individual to daydream, reflect on their past, imagine possible future scenarios, and consider the viewpoints of others. These flexible self-relevant mental explorations enable the anticipation and evaluation of events before they occur, and are essential for successful social interactions. Such self-projective efforts are particularly vulnerable to disruption in frontotemporal dementia (FTD), a neurodegenerative disorder involving damage to the frontal and temporal lobes of the brain. In this Review, we explore how the progressive degeneration of the neural networks in two subtypes of FTD-the behavioral variant and semantic dementia-affects key structures of the default network and putative self-projective functions. We examine the available evidence from studies of autobiographical memory, episodic future thinking, theory of mind, moral reasoning, and economic decision-making in these neurodegenerative diseases. Finally, we propose that the mapping of default-network functions onto discrete subsystems of the default network may need revision in light of neuropsychological and clinical evidence from studies in patients with FTD.
越来越多的证据表明，当个体进行自我思考时，大脑会启动所谓的默认网络，使个体能够做白日梦、反思过去、想象可能的未来情景、并考虑他人的观点。这些灵活的自我相关的心理探索使个体能够在事件发生之前进行预测和评估，并且对成功的社交互动至关重要。这种自我投射的努力在额颞叶痴呆（FTD）中特别容易受到干扰，这是一种涉及大脑额叶和颞叶损伤的神经退行性疾病。在这篇综述中，我们探讨了 FTD 的两种亚型——行为变体和语义性痴呆——中神经网络的逐渐退化如何影响默认网络的关键结构和假定的自我投射功能。我们研究了这些神经退行性疾病中自传体记忆、情景性未来思维、心理理论、道德推理和经济决策等方面的现有研究证据。最后，我们提出，鉴于 FTD 患者研究中的神经心理学和临床证据，需要对默认网络功能映射到默认网络的离散子系统进行修正。
