Intention to encode boosts memory-related pre-stimulus EEG beta power
Intention to encode boosts memory-related pre-stimulus EEG beta power
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DOI：
10.1016/j.neuroimage.2015.11.024
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发表时间：
2016-01-15
期刊：
影响因子：
5.7
通讯作者：
Rose, Michael
中科院分区：
文献类型：
--
作者：
Schneider, Signe Luisa;Rose, Michael
刺激前的振荡性大脑活动可以预测在稍后的时间点对即将到来的刺激的记忆程度。最近，在编码期间，在进行中的θ（5-8 Hz）和低β（13-17 Hz）频带中增加的预刺激功率与增强的记忆性能相关联。当在刺激开始之前呈现线索时，编码相关的大脑激活可以被认为是为即将到来的刺激做准备的标志。在这里，我们调查是否有意编码以下刺激到长期记忆影响这些准备前刺激激活编码过程中。两组18名参与者参加了随后的记忆范式。研究人员记录了参与者的脑电图（EEG），同时向他们展示了一系列图片，每一张图片之前都有一个提示，这些提示应该根据动物性进行分类。一组被告知即将到来的识别任务，因此能够开发编码刺激的意图（有意编码），而另一组没有收到此信息（附带编码）。之后，对图片的识别进行了测试。仅在有意编码期间，发现在θ和低β波段的功率在后来被记住的图片与后来被遗忘的图片相比发生之前显著增加。组间比较证实，在低β波段，有意编码比偶然编码的记忆相关功率增加更大。这些研究结果表明，振荡状态与成功的编码可以主动启动，如果打算编码的刺激。因此，我们建议低β带激活刺激发作前是一个指标的内存特定的准备即将到来的刺激。(C)2015 Elsevier Inc. All rights reserved.
Pre-stimulus oscillatory brain activity can predict the degree to which an upcoming stimulus will be remembered at a later point in time. Recently, increased pre-stimulus power in ongoing theta (5-8 Hz) and low beta (13-17 Hz) bands during encoding has been associated with enhanced memory performance. When a cue is presented before stimulus onset, encoding-related brain activations may be regarded as a sign of preparation for the upcoming stimulus. Here, we investigated whether the intention to encode the following stimulus into long-term memory affects these preparatory pre-stimulus activations during encoding. Two groups of 18 participants took part in a subsequent memory paradigm. Electroencephalogram(EEG) was recorded while participants were presented with a series of pictures, each one preceded by a cue, which were supposed to be classified according to animacy. One group was informed about the upcoming recognition task and therefore was enabled to develop the intention to encode the stimuli (intentional encoding), whereas the other group did not receive this information (incidental encoding). Afterwards, recognition of the pictures was tested. During intentional encoding only, power in theta and low beta bands was found to be significantly increased before the onset of pictures that were later remembered compared to later forgotten ones. Group comparisons confirmed greater memory-related power increases in the low beta band for intentional than incidental encoding. These findings indicate that oscillatory states that are associated with successful encoding can be initiated voluntarily if the intention to encode the stimuli is given. We therefore suggest low beta band activation before stimulus onset to be an indicator of memory-specific preparation for an upcoming stimulus. (C) 2015 Elsevier Inc. All rights reserved.