Harry Potter and the Chamber of <i>What</i>?: the impact of what individuals know on word processing during reading

During reading, effects of contextual support indexed by N400 – a brain potential sensitive to semantic activation/retrieval – amplitude are presumably mediated by comprehenders’ world knowledge. Moreover, variability in knowledge may influence the contents, timing, and mechanisms of what is brought to mind during real-time sentence processing. Since it is infeasible to assess the entirety of each individual’s knowledge, we investigated a limited domain – the narrative world of Harry Potter (HP). We recorded event-related brain potentials while participants read sentences ending in words more/less contextually supported. For sentences about HP, but not about general topics, contextual N400 effects were graded according to individual participants’ HP knowledge. Our results not only confirm that context affects semantic processing by ∼250 ms or earlier, on average, but empirically demonstrate what has until now been assumed – that N400 context effects are a function of each individual’s knowledge, which here is highly correlated with their reading experience.阅读过程中，以N400（一种对语义激活与提取敏感的脑电位）的波幅为指标的语境支持效应，推测由个体的世界知识所介导。此外，知识储备的个体差异可能会影响实时句子加工过程中被激活的心理内容、激活时序与作用机制。由于无法全面评估每个个体的全部知识储备，本研究选取了一个受限研究领域——《哈利·波特》（Harry Potter，HP）的叙事世界观。本研究记录了被试阅读句尾词汇语境支持程度存在高低差异的句子时的事件相关脑电位（event-related brain potentials，ERP）。针对《哈利·波特》相关句子（而非通用话题句子），语境诱发的N400效应会根据被试个体的《哈利·波特》知识水平呈现分级差异。本研究结果不仅证实了语境通常会在平均约250毫秒或更早的时间窗口内影响语义加工，还以实验数据验证了迄今仅为理论假设的结论：N400的语境效应随个体知识水平而异，而本研究中的个体知识水平与其阅读体验高度相关。