Cano Maya E, Knight Robert T
Helen Wills Neuroscience Institute, University of California, Berkeley Berkeley, CA, USA.
Helen Wills Neuroscience Institute, University of California, BerkeleyBerkeley, CA, USA; Department of Psychology, University of California, BerkeleyBerkeley, CA, USA.
Front Hum Neurosci. 2016 Mar 30;10:133. doi: 10.3389/fnhum.2016.00133. eCollection 2016.
The neural basis of motivated forgetting using the Think/No-Think (TNT) paradigm is receiving increased attention with a particular focus on the mechanisms that enable memory suppression. However, most TNT studies have been limited to the visual domain. To assess whether and to what extent direct memory suppression extends across sensory modalities, we examined behavioral and electroencephalographic (EEG) effects of auditory TNT in healthy young adults by adapting the TNT paradigm to the auditory modality. Behaviorally, suppression of memory strength was indexed by prolonged response time (RTs) during the retrieval of subsequently remembered No-Think words. We examined task-related EEG activity of both attempted memory retrieval and inhibition of a previously learned target word during the presentation of its paired associate. Event-related EEG responses revealed two main findings: (1) a centralized Think > No-Think positivity during auditory word presentation (from approximately 0-500 ms); and (2) a sustained Think positivity over parietal electrodes beginning at approximately 600 ms reflecting the memory retrieval effect which was significantly reduced for No-Think words. In addition, word-locked theta (4-8 Hz) power was initially greater for No-Think compared to Think during auditory word presentation over fronto-central electrodes. This was followed by a posterior theta increase indexing successful memory retrieval in the Think condition. The observed event-related potential pattern and theta power analysis are similar to that reported in visual TNT studies and support a modality non-specific mechanism for memory inhibition. The EEG data also provide evidence supporting differing roles and time courses of frontal and parietal regions in the flexible control of auditory memory.
使用“想/不想”（TNT）范式进行动机性遗忘的神经基础正受到越来越多的关注，尤其聚焦于能够实现记忆抑制的机制。然而，大多数TNT研究仅限于视觉领域。为了评估直接记忆抑制是否以及在何种程度上跨感觉模态存在，我们通过将TNT范式应用于听觉模态，研究了健康年轻成年人中听觉TNT的行为和脑电图（EEG）效应。在行为上，记忆强度的抑制通过随后被记住的“不想”单词检索期间延长的反应时间（RTs）来衡量。我们在呈现配对联想词时，检查了与尝试记忆检索和对先前学习的目标词的抑制相关的任务EEG活动。事件相关EEG反应揭示了两个主要发现：（1）在听觉单词呈现期间（约0 - 500毫秒），中央区域“想>不想”的正波；（2）从约600毫秒开始，顶叶电极上持续的“想”正波，反映了记忆检索效应，而“不想”单词的这种效应显著降低。此外，在额中央电极上，听觉单词呈现期间，“不想”单词的锁词theta（4 - 8 Hz）功率最初比“想”单词更大。随后，在“想”条件下，后部theta增加表明成功的记忆检索。观察到的事件相关电位模式和theta功率分析与视觉TNT研究中报告的相似，并支持记忆抑制的模态非特异性机制。EEG数据还提供了证据，支持额叶和顶叶区域在灵活控制听觉记忆中的不同作用和时间进程。
