算术估算策略运用的认知与神经基础

In recent years, strategy use (including two aspects: strategy selection and strategy execution), one of the frontier topics in cognitive science and educational psychology, was thoroughly discussed by both fields. It was also gradually becoming a prominent issue to which educational neuroscience researchers paid more and more attention. Revealing the intrinsic mechanism of strategy use can not only contribute to understanding human's complicated cognitive flexibility displayed in various domains exhaustively, but also provide critical educational implications for individual development. Computational estimation was regarded as one of typical arithmetic cognition tasks to explore the characteristics of approximate number system (ANS) in complex arithmetic operations in human by contemporary mathematical cognition researchers. The aim of the present proposal is to use two novel paradigms in strategy change study - the choice/no choice method and operand-recognition paradigm (ORP)- to investigate the synthesized contributions of cognitive factors, such as working memory, central executive load, and cognitive switching, et al., on the different behavioral features, eye movement and brain activation patterns of math average- achievers and mathematical disables. The participants will be arranged to apply various complex arithmetic strategies in computational estimation tasks under different guidance. The choice/no choice method and ORP paradigm will be combined with eye tracking technique and event-related potential technique in specific experimental designs. After the comparison and integration with the prior findings of strategy use in exact calculation, which is regarded as one of typical arithmetic cognition tasks to stand for the precise number system in human, we will deepen the existing theoretical understandings of psychological and physiological mechanisms about how arithmetic strategies work in mathematical cognition field. In addition, findings obtained from our subsequent researches can promulgate the flexibility, adaptability and domain specificity in cognitive strategy operations thoroughly, and additionally provide some innovative perspectives for the formulation of more pertinent and effective strategy intervention programmes.

策略运用作为认知科学和教育心理学近年来深入探讨的前沿交叉课题，也是教育神经科学研究者关注的热点问题，揭示其内在发生机制既有助于深刻理解人类在各领域表现出的复杂的认知灵活性，亦对个体发展具有重大教育意义。估算被视为揭示复杂算术加工中近似数字系统运作特点的典型任务。本课题拟采用将选择/无选法、运算数再认范式与眼动或事件相关电位技术相结合的方法，考察工作记忆、中央执行负荷、认知转换等因素在影响正常与数学困难个体复杂算术估算策略运用时所表现出的行为特点、眼动模式及其在时空两维上所表现出的脑激活模式。通过与心算（反映精确计数系统的典型任务）领域的既有发现比较整合，深入揭示个体算术策略操作所具有的灵活性、适应性和领域特殊性，提升对认知策略运用内在机制的理论认识，为制定更为有效的策略干预训练方案提供新颖思路。

策略运用已被视作衡量个体认知灵活性水平高低的重要标志，其内在机制的揭示既有助于深刻理解人类在各领域表现出的复杂的认知灵活性，亦对个体发展具有重大教育意义。人类大脑中并存着“精确计数”和“近似数量”两套数字表征系统，前者主要依赖于言语表征，易受教育文化影响，主要借助计数、心算等任务对精确计数系统进行考察，后者则主要依赖非符号空间表征，具有较明显的进化基础，主要借助数字比较、数字判断、估计等任务对近似数量系统进行考察。以往算术策略研究主要采用心算任务，较少涉及估算任务。本项目采用选择/无选法、运算数再认范式与眼动或事件相关电位技术相结合的方法，考察工作记忆、中央执行负荷、认知转换等因素在影响正常与数学困难个体复杂算术估算策略运用时所表现出的行为特点、眼动模式及其在时空两维上所表现出的脑激活模式。主要发现：⑴对于工作记忆的不同成分，仅中央执行对不同年龄段个体的策略运用具有稳定的预测作用，且近似数量系统这一领域特殊因素会通过工作记忆影响个体表现；⑵中央执行负荷对个体的影响存在年龄差异，且对数困儿童阻碍作用更大。电生理学证据表明负荷会阻碍个体对数字信息的加工比较过程，但在长时记忆信息提取上这种阻碍作用相对较弱，揭示了负荷影响的内在神经机制；⑶中央执行功能的相关研究中，认知转化对算术策略的影响存在年龄差异，眼动和电生理指标表明转化使个体注视次数增加，影响初始策略的选择，而对于中央执行抑制能力的训练对负荷的影响或数困儿童的表现起到一定的改善作用。上述研究发现，回答了本项目对于算术估算策略运算的假设，在一定程度上揭示了其认知与神经基础，丰富了相关领域的发现，验证和完善了已有理论。