# Correlation Between Co-Design and Psychological Need Satisfaction Based on fNIRs Hyperscanning
## 1 Introduction  
The predecessors of co-design include action research and socio-technical design, which emerged alongside the development of participatory design [1]. It can be traced back to Scandinavia in the 1970s and is also considered the earliest form of participatory design [2], also known as cooperative design. Since then, the advantages and importance of interdisciplinary collaboration have gradually emerged, and designers are increasingly eager to approach the future users their designs are aimed at [3]. Therefore, a method called action research has developed and evolved in the field of design practice. This method emphasizes the need for active collaboration between researchers and workers by providing feedback to researchers based on their practical experience in order to optimize and improve the actual work situation of staff [4]. At the same time, the participatory design movement has been widely spread around the world. In September 1971, the British Manchester Design Research Association held a conference called \"Design Participation\". In the preface of the conference, [PERSON] pointed out the responsibility of designers in predicting the adverse effects of projects and emphasized the need for new design methods to address the constantly upgrading problems of the artificial world. He believed that involving peoplein decision making may be of certain importance, and since then, users and consumers have gradually been given more initiative and influence [5]. To this day, user-centered design methods are unable to address the scale and complexity of challenges faced by the design industry. Therefore, instead of simply designing products centered around users, we are beginning to explore co-design services between designers and stakeholders such as users, which is a practice of involving users in the innovation process. The trend in design applications is to leverage the characteristics of collaborative design to meet user needs. As a design methodology, it involves involving users throughout the design process to jointly complete activities such as requirement analysis and creative generation [6] in order to ensure that the final product or service better meets users' needs, expectations, and preferences. [PERSON] [7] first defined it as a system design carried out jointly with users as an expert; [PERSON] [8] believes that it is a role exchange that involves designers in the user world and allows users to directly participate in the design; [PERSON] [9] views this design as a process in which users and designers become partners and collaborate to create knowledge; and [PERSON] [10] takes the exploration of user-driven innovation by end-users as the perspective and approach for such designs. The summary of various viewpoints makes it clear that collaborative design is a method that emphasizes the use of strong participatory approaches such as collaboration, respect, participation, and co-construction, with both users and designers as the main body. It is hoped that users can be deeply involved in the design process to drive innovation. The collaborative design effectively implements the design concept of \"people-oriented\". Compared with the user-centered design concept, users are no longer passive choices, ensuring the scientific nature of the design. Collaborative design is also an important direction for product design reform, providing a good design method to better meet users' emotional needs and reflect personalization. Collaborative design from multiple parties has been widely applied in fields such as education, politics [11], and healthcare [12], and has produced services and systems that better meet the needs of the public. Empirical research on neurobehavior is an effective path for objectively observing team collaboration tasks. The complexity and implicit nature of cooperation level in the collaborative process of multi-party team tasks make it impossible to meet current observation needs solely through subjective evaluation methods.