Abla Dilshat, Okanoya Kazuo
Laboratory for Biolinguistics, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Neurosci Res. 2009 Jun;64(2):185-90. doi: 10.1016/j.neures.2009.02.013. Epub 2009 Mar 13.
Behavioral experiments have found that infants and adults learn statistically defined patterns presented in auditory and visual input sequences in the same manner regardless of whether the input was linguistic (syllables) or nonlinguistic (tones and shapes). In order do determine the time course and neural processes involved in online word segmentation and statistical learning of visual sequence, we recorded event-related potentials (ERPs) while participants were exposed to continuous sequences with elements organized into shape-words randomly connected to each other. After viewing three 6.6min sessions of sequences, the participants performed a behavioral choice test. The participants were divided into two groups (high and low learners) based on their behavioral performance. The overall mean performance was 72.2%, indicating that the shape sequence was segmented and that the participants learned the shape-triplets statistically. Grand-averaged ERPs showed that triplet-onset (the initial shapes of shape-words) elicited larger N400 amplitudes than did middle and final shapes embedded in continuous streams during the early learning sessions of high learners, but no triplet-onset effect was found among low learners. The results suggested that the N400 effect indicated online segmentation of the visual sequence and the degree of statistical learning. Our results also imply that statistical learning represents a common learning device.
行为实验发现，婴儿和成人以相同的方式学习听觉和视觉输入序列中按统计定义的模式，无论输入是语言性的（音节）还是非语言性的（音调与形状）。为了确定在线单词分割和视觉序列统计学习所涉及的时间进程和神经过程，我们在参与者接触由相互随机连接的形状词组成的连续序列时记录了事件相关电位（ERP）。在观看三个6.6分钟的序列后，参与者进行了行为选择测试。根据行为表现，参与者被分为两组（高学习者和低学习者）。总体平均表现为72.2%，表明形状序列被分割，并且参与者在统计上学习了形状三元组。总体平均ERP显示，在高学习者的早期学习阶段，三元组起始（形状词的初始形状）比连续流中嵌入的中间和最终形状引发了更大的N400波幅，但在低学习者中未发现三元组起始效应。结果表明，N400效应表明视觉序列的在线分割和统计学习程度。我们的结果还意味着统计学习是一种常见的学习机制。
