数量表征能力是个体最基本的数认知能力，有着重要的进化学意义，尤其是对幼儿甚至婴儿的数量表征能力的探讨对揭示人类数量认知的起源有着重要价值。此外，结合成人被试，从多个视角系 统地剖析数量表征的特点能为解答不同数量范围内的表征异同以及不同数量形式的表征异同起到重要作用。 数量表征（magnitude representation）是指个体头脑内部对数量刺激的解释、表达与操作过程（Brysbaert, 2004）。其中，个体不需要依赖符号知识对视觉、听觉或跨通道呈现的实物或实物记号的数量刺激进行表达和运算的过程称为非符号数量表征（non-symbolic magnitude representation）；而依赖于符号知识对数字和数词形式的数量进行表征，称为符号数量表征（symbolic magnitude representation）。 以往研究对不同数量范围内的数量表征特点进行了大量的研究，尤其在非符号数量表征领域，对鸽子、老鼠、灵长目动物和人类的非符号数量表征特点的探讨方面积累了丰富的颇有影响力的研究成果。然而，对于大范围（4以上）的数量表征和小范围的数量表征是否依赖于不同的心理机制，以及是否存在于分离的表征系统中等问题，仍然是当前国际心理学界重要的理论争论之一；此外，对于非符号数量表征与符号数量表征的关系也存在争议，有研究者认为主体对符号数量表征会表现出与非符号数量表征的近似性特点，但也有人持两个表征系统独立发展的观点。有鉴于此，在已有研究的基础上，本研究通过两个研究共八个实验分别探讨了幼儿和成人的数量表征特点。研究一采用动画呈现数量刺激的方式，通过单通道点集比较、单通道数字比较、跨通道点集比较和跨通道数字比较四个实验，在严格控制知觉线索的前提下，分别考察了3 – 6岁的幼儿在视觉单通道条件和视听跨通道条件下进行符号数量表征和非符号数量表征的特点，及其在大、小数量范围内表征的特点。并通过唱数任务、给数取物任务、给物说数任务考察了幼儿的数量熟悉性与数量表征的关系。研究二以大学生为被试，从注意资源的角度考察了大、小数量表征受注意负荷影响的异同。采用双任务范式，通过四个实验分别考察了无、低、高三种注意负荷条件对不同数量范围内的非符号数量表征和符号数量表征精确性的影响。考虑到本研究的任务量大，任务要求较复杂，幼儿阶段的注意保持度、任务理解能力和操作能力等尚未发展成熟，且本研究对注意负荷的考察不关注其发展特点，故采用成人被试以便纯粹地、全面地考察注意负荷对数量表征的影响。其中，子研究一通过点集比较双任务、点集估计双任务和线段估计双任务等三个实验系统考察了注意负荷对非符号数量表征的影响。子研究二则采用符号比较双任务考察了注意负荷对符号数量表征的影响。本研究主要得到了以下研究结果及结论：研究一发现：1. 4岁以上幼儿能进行单通道和跨通道的数量表征，说明其能进行不受具体感觉通道限制的抽象数量表征；而4岁以下的幼儿在跨通道的表现局限于小数量范围；且韦伯分数显示幼儿在不同条件下的数量表征均表现出了随年龄增大而越来越精确的趋势；此外，中班和大班幼儿的数量熟悉性均较高，数量熟悉性仅影响小班儿童数量表征的反应速度但并不影响数量表征的正确率；2. 幼儿在非符号的大数量和小数量比较过程中均表现出了近似表征的特点，在符号数量比较过程中表现出了精确比较的特点，未表现出比例效应和距离效应；这说明幼儿并没有表现出明显的非符号数量表征对符号数量表征的影响。研究二发现：注意负荷对成人符号数量表征和非符号数量表征的精确性都会产生干扰，对非符号数量表征的干扰更大。这说明成人的符号与非符号数量表征存在某些共同点；其次，注意负荷对大、小数量表征均会产生干扰，这个结果并未支持小数量表征处于前注意阶段的理论假设，反而支持了大、小范围数量没有本质区别的理论假设。综合上述研究结论，本研究认为抽象的、超出感觉通道限制的非符号数量表征能力可能并非是与生俱来的，它可能受到了成熟和后期学习和生活经验的影响；非符号数量表征与符号数量表征的联系也可能需要在发展过程中逐渐建立；最后，小数量和大数量表征可能存在于同一种表征系统中。

Quantitative information is an indispensible part of technological society nowadays. The understanding and processing of numerical quantity is crucial for success in education and employment. People are incessantly comparing things in the environment, activities such as utilizing numbers to measure the value of commodities and income, to represent students’ mastering degree of certain subjects, or to express the temperature of tomorrow. There are countless examples. All of these cannot be separated from magnitude representation.Magnitude representation is one of the most important basic mental abilities. Sensitivity to numerical magnitude has been demonstrated in other species and emerges early in human development.But how do people represent all these different stimuli? How does the human brain process these quantities? Is there only one shared representation for magnitude, or are different dimensions? These questions are fundamental to understanding how numerical information is processed.Some studies confirmed that non-symbolic magnitude representation affects symbolic magnitude representation, thus influences symbolic magnitude representation to demonstrate some similar characteristics with non-symbolic magnitude representation. While some believed that these two representations developed independently. Moreover, some investigations suggest that there are two separate representation systems for small and large numbers, while some recommend there is one continuous representation system.Based on such long-standing debates, the current study contained two sub-studies. The first study aims to figure out what exactly the charactersitics of magnitude representaion are during early childhood from the point view of symbolic and non-symbolic magnitude representation, and in which ways these two forms of magnitude representation interact with each other. We used four experiments (visual dots comparison, visual-audio dots comparison, visual digits comparison and visual-audio digits comparison) to look into the performance of children in visual and visual-auditory cross-modal magnitude representation situation. The second study delved into the role of spatial attention load to adult’s accuracy on magnitude representation tasks. Taking the advantage of a dual-task paradigm, we employed four experiments (dots comparison, dots estimation, line estimation and digits comparison) to explore the attention load’s effect to both small and large magnitude, under different representation circumstances. The main findings of the current study are as follows:From the first study we can conclude:1. Children beyond 4-year-old can successfully represent in both single modal and cross-modal tasks, which indicated that number representations can be abstract and do not confined by specific sensory modalities. Meanwhile, their accuracy of representations grows with age in all the conditions. Moreover, the magnitude familiarity were high in children of middle and high grade in kindergarten, such familiarity only affect the reaction speed of representation but not accuracy.2. The characteristics of approximate magnitude representation were found in young children, unless small or large non-symbolic magnitude, but this result was not found in symbolic magnitude representation. This means that preschool children do not show the interaction of non-symbolic and symbolic representations.From the second study we can conclude:Attention loads can interrupt adults’ accuracy of magnitude representations, whenever in symbolic or non-symbolic conditions, and the effect was stronger in nonsymbolic representation situation. This indicated some common point under these two magnitude types. Besides, the attention load interfere the performance of both small and large magnitude, and this result showed that small magnitude representation may be not under pre-attention stage, there might be no essential differences in small and large range.To sum up, this study informs that the abstract, beyond specific sensory modal magnitude representation is not innate. It may be influenced by mature and educational experience, and the link of non-symbolic and symbolic representation may be established during development. Last but not the least, both the small and large magnitude may exist in a unitary representation system.