Yazar Yasemin, Bergström Zara M, Simons Jon S
Department of Psychology, University of Cambridge, Cambridge, United Kingdom; Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom.
Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom; Department of Psychology, University of Kent, Kent, United Kingdom.
PLoS One. 2014 Oct 21;9(10):e110414. doi: 10.1371/journal.pone.0110414. eCollection 2014.
The contribution of lateral parietal regions such as the angular gyrus to human episodic memory has been the subject of much debate following widespread observations of left parietal activity in healthy volunteers during functional neuroimaging studies of memory retrieval. Patients with lateral parietal lesions are not amnesic, but recent evidence indicates that their memory abilities may not be entirely preserved. Whereas recollection appears intact when objective measures such as source accuracy are used, patients often exhibit reduced subjective confidence in their accurate recollections. When asked to recall autobiographical memories, they may produce spontaneous narratives that lack richness and specificity, but can remember specific details when prompted. Two distinct theoretical accounts have been proposed to explain these results: that the patients have a deficit in the bottom-up capturing of attention by retrieval output, or that they have an impairment in the subjective experience of recollection. The present study aimed to differentiate between these accounts using continuous theta burst stimulation (cTBS) in healthy participants to disrupt function of specific left parietal subregions, including angular gyrus. Inconsistent with predictions of the attentional theory, angular gyrus cTBS did not result in greater impairment of free recall than cued recall. Supporting predictions of the subjective recollection account, temporary disruption of angular gyrus was associated with highly accurate source recollection accuracy but a selective reduction in participants' rated source confidence. The findings are consistent with a role for angular gyrus in the integration of memory features into a conscious representation that enables the subjective experience of remembering.
在记忆检索的功能神经影像学研究中，健康志愿者左侧顶叶活动广泛被观察到之后，诸如角回等外侧顶叶区域对人类情景记忆的贡献一直是诸多争论的主题。患有外侧顶叶病变的患者并非失忆，但最近的证据表明他们的记忆能力可能并未完全保留。当使用诸如来源准确性等客观测量方法时，回忆似乎完好无损，但患者对其准确回忆的主观信心往往会降低。当被要求回忆自传体记忆时，他们可能会产生缺乏丰富性和特异性的自发叙述，但在得到提示时能够记住具体细节。已经提出了两种不同的理论解释来解释这些结果：一种是患者在由检索输出自下而上捕获注意力方面存在缺陷，另一种是他们在回忆的主观体验方面存在损伤。本研究旨在通过在健康参与者中使用连续theta爆发刺激（cTBS）来破坏包括角回在内的特定左侧顶叶亚区域的功能，以区分这些解释。与注意力理论的预测不一致，角回cTBS导致的自由回忆损伤并不比线索回忆更大。支持主观回忆解释的预测，角回的暂时破坏与高度准确的来源回忆准确性相关，但参与者对来源的评分信心有选择性降低。这些发现与角回在将记忆特征整合到有意识表征中从而实现记忆的主观体验方面的作用是一致的。
