想,不想范式(Think/No—think,TND是基于go/no-go范式提出来的用于研究动机性遗忘过程的实验范式,主要过程是指个体对于记忆的提取抑制可以导致随后该记忆的遗忘。近年来TNT范式的大量行为学研究都一致性地发现记忆提取抑制可以产生负性控制效应,验证了在实验室情境下对动机性遗忘进行研究的可行性。其中,负性控制效应指的是压抑条件的项目相对于基线条件的项目的回忆量有显著降低。关于动机性遗忘发生的神经机制的探讨已积累了大量的研究证据,总结脑电(EEG)和功能核磁共振(fMRI)两个模态的研究,我们提出了动机性遗忘发生的多模态功能网络模型。最后,在该模型的基础上,我们展望了TNT范式未来的研究方向,其中特别注意到同步EEG-fMRI技术的应用有望为我们揭示出记忆提取抑制导致的动机性遗忘发生的动态过程。
Motivated forgetting is an important aspect of an effective memory system. People have motivations to limit the time they spend thinking about unpleasant experiences, thus they eventually forget those memories. The think/no-think (TNT) paradigm is proposed to study the process of motivated forgetting based on the go/no-go experimental paradigm. This paradigm emphasizes that individuals' subjective suppression of unwanted memories reduces their later conscious recall. In recent years, many TNT behavioral studies have consistently indicated that memory suppression can produce a negative control effect, thus verify the feasibility of the implementation of motivated forgetting in a laboratory context. In this review, we summarized some main characteristics of the negative control effect in order to help future research implemented by TNT to obtain the inhibitory control processes to study motivated forgetting. A recent discussion on the neural mechanisms of motivated forgetting has accumulated a great deal of research evidence. Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are two widely used brain techniques to determine these inhibitory control processes of motivated forgetting. First, ERP studies of motivated forgetting using the TNT paradigm have revealed a smaller parietal episodic memory effect appears 400-800 ms after target stimulus onset during the memory retrieval suppression. Moreover, ERP evidence has indicated that N2, which indexes cognitive control, is larger during retrieval suppression. Recent EEG studies of motivated forgetting have revealed an increase of alpha and theta oscillations of memory suppression. More interestingly, fMRI evidence has showed that suppressing awareness of an unwelcome memory was achieved by inhibitory control processes mediated by the lateral prefrontal cortex. These mechanisms interact with brain regions that represent experiences in memory, disrupting traces that support retention. Moreover, suppressing retrieval of unwanted m