Early research on the referential process (RP) focused on the function of connecting words and the entities to which they refer, as a trait, a dimension on which people differed in a relatively stable manner. The first study found a correspondence between retrieval time for a small set of color names, hand movements accompanying speech, and features of language content and style, such as use of particular pronouns and direct quotes. The second study supported these results using an early version of the Referential Activity (RA) scales, as well as a task of generating labels for subtly differing stimuli where labels had not been provided. Another study provided a close examination of the relation of hand and body movements to the functions of the RP. The current forms of the RA scales, Concreteness, Specificity, Clarity, and Imagery, which serve as the basis for the computerized measures of the Symbolizing function, were developed based on those early studies. Recent research on the RP, some of which will be presented in this issue, has focused primarily on the Symbolizing function as a state rather than trait dimension, and has examined factors affecting variation in this function. The early research also serves as a basis for empirical study of the other functions of the RP. Through interactive development of measures and theory, in experimental and clinical settings, the constructs of the multiple code theory and the RP continue to be refined and redefined.

对指称过程 (RP) 的早期研究集中在连接单词及其所指实体的功能上，作为特征，人们以相对稳定的方式在该维度上有所不同。第一项研究发现，一小组颜色名称的检索时间、语音伴随的手部动作与语言内容和风格的特征（例如特定代词和直接引用的使用）之间存在对应关系。第二项研究使用参考活动 (RA) 量表的早期版本以及为未提供标签的细微不同刺激生成标签的任务支持这些结果。另一项研究对手和身体运动与 RP 功能的关系进行了仔细检查。RA 量表的当前形式、具体性、特异性、清晰度和作为符号化功能计算机化测量基础的图像是在这些早期研究的基础上开发的。最近关于 RP 的研究（其中一些将在本期中介绍）主要集中在作为状态而非特征维度的象征功能，并研究了影响该功能变化的因素。早期的研究还可以作为对 RP 其他功能进行实证研究的基础。通过测量和理论的交互发展，在实验和临床环境中，多重代码理论和 RP 的结构不断被完善和重新定义。