State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.
PLoS One. 2010 Oct 6;5(10):e13204. doi: 10.1371/journal.pone.0013204.
The left midfusiform and adjacent regions have been implicated in processing and memorizing familiar words, yet its role in memorizing novel characters has not been well understood.
METHODOLOGY/PRINCIPAL FINDINGS: Using functional MRI, the present study examined the hypothesis that the left midfusiform is also involved in memorizing novel characters and spaced learning could enhance the memory by enhancing the left midfusiform activity during learning. Nineteen native Chinese readers were scanned while memorizing the visual form of 120 Korean characters that were novel to the subjects. Each character was repeated four times during learning. Repetition suppression was manipulated by using two different repetition schedules: massed learning and spaced learning, pseudo-randomly mixed within the same scanning session. Under the massed learning condition, the four repetitions were consecutive (with a jittered inter-repetition interval to improve the design efficiency). Under the spaced learning condition, the four repetitions were interleaved with a minimal inter-repetition lag of 6 stimuli. Spaced learning significantly improved participants' performance during the recognition memory test administered one hour after the scan. Stronger left midfusiform and inferior temporal gyrus activities during learning (summed across four repetitions) were associated with better memory of the characters, based on both within- and cross-subjects analyses. Compared to massed learning, spaced learning significantly reduced neural repetition suppression and increased the overall activities in these regions, which were associated with better memory for novel characters.
CONCLUSIONS/SIGNIFICANCE: These results demonstrated a strong link between cortical activity in the left midfusiform and memory for novel characters, and thus challenge the visual word form area (VWFA) hypothesis. Our results also shed light on the neural mechanisms of the spacing effect in memorizing novel characters.
左侧中梭状回及其相邻区域已被证明与熟悉单词的处理和记忆有关，但它在记忆新字符方面的作用尚未得到很好的理解。
方法/主要发现：本研究使用功能磁共振成像（fMRI），检验了左侧中梭状回也参与记忆新字符的假设，并且间隔学习可以通过在学习过程中增强左侧中梭状回的活动来增强记忆。19 名母语为汉语的读者在记忆 120 个对他们来说是新的韩语字符的视觉形式时接受了扫描。每个字符在学习过程中重复四次。通过使用两种不同的重复时间表（集中学习和间隔学习），在相同的扫描会话中随机混合，来操纵重复抑制。在集中学习条件下，四次重复是连续的（使用随机的间隔重复间隔来提高设计效率）。在间隔学习条件下，四次重复是交错的，最小的重复间隔为 6 个刺激。在扫描后一小时进行的识别记忆测试中，间隔学习显著提高了参与者的表现。基于内和跨被试分析，学习过程中（四次重复的总和）左侧中梭状回和下颞叶回的活动越强，与对字符的记忆越好相关。与集中学习相比，间隔学习显著减少了这些区域的神经重复抑制，并增加了整体活动，这与对新字符的更好记忆相关。
结论/意义：这些结果表明，左侧中梭状回的皮层活动与对新字符的记忆之间存在很强的联系，从而对视觉词形区（VWFA）假说提出了挑战。我们的研究结果也揭示了记忆新字符的间隔效应的神经机制。
