Words-In-Sequence Memory Formed by Eye Movement Sequences During Reading: A Network Model Based on Theta Phase Coding
Words-In-Sequence Memory Formed by Eye Movement Sequences During Reading: A Network Model Based on Theta Phase Coding
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DOI：
10.1007/s11063-017-9632-4
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发表时间：
2018-06-01
影响因子：
3.1
通讯作者：
Sato，Naoyuki
中科院分区：
文献类型：
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作者：
Sato，Naoyuki
揭示了海马体维持情景记忆的神经机制（即，个人事件的记忆）是我们理解人类智能的一个基本问题。基于θ相位编码的时间压缩机制已被证明对于在行为时间尺度（>几秒）上发生的情景记忆的编码是必不可少的，并且能够操作顺序和空间记忆。然而，情景记忆模型应发展到处理更多的语义丰富的内容。在这里，记忆从阅读的一段文献进行了评估，使用基于θ相位编码的网络模型。同时应用两种类型的输入：单词输入，由在阅读期间获得的眼动序列定义，每个固定单词由从具有大型文本语料库的统计语言模型计算的向量编码;和序列输入，由随机激活定义，并表示独立于眼动的逐渐变化的输入模式。实验结果成功地证明了由6分钟阅读过程中的单词序列所产生的记忆，并且序列输入的记忆网络被证明是提取所必需的。这一结果的特点是在theta相位编码形成的网络中存在一个词的序列结构，其中，序列单元之间的单向连接主要引起序列激活，而序列激活又通过序列到词单元的单向连接进一步传递词单元激活。这表明θ相位编码在情景记忆的形成中具有普遍作用。
Revealing the neuronal mechanisms enabling the hippocampus to maintain episodic memory (i.e., memory for personal events) is a fundamental issue for our understanding of human intelligence. A temporal compression mechanism based on theta phase coding has been shown to be essential for the encoding of episodic memory occurring on a behavioral timescale (>a few seconds) and capable of operating sequential and spatial memory. However, episodic memory models should be developed to handle more semantic-rich contents. Here, memory from the reading of a passage of literature was evaluated using a network model based on theta phase coding. Two types of input were simultaneously applied: word inputs, defined by the eye movement sequence obtained during the reading, with each fixated word encoded by a vector computed from a statistical language model with a large text corpus; and sequence inputs, defined by random activations and representing a gradually changing input pattern, independent of the eye movement. The results successfully demonstrated a memory generated by the word sequence from the 6-min reading session, and the memory network for the sequence input was shown to be essential for the retrieval. This result was characterized by a words-in-sequence structure in the network formed by theta phase coding, of which, the unidirectional connections among sequence units dominantly evoked the sequential activation, which further conveyed word unit activations through the unidirectional connections from the sequence to the word units. This suggests a general role for theta phase coding in the formation of episodic memory.