A research group led by Associate Professor Yoshihiro Nakata from the Graduate School of Informatics and Engineering at The University of Electro-Communications, Japan, in collaboration with researchers from Doshisha University and Otemon Gakuin University, has developed an edible agent capable of social interaction through vocalizations and movement. Their study examined mind perception of the edible agent and its relationship with reluctance to eat and guilt. The research was published in PLOS ONE.
Understanding psychological acceptance of food is important for studying food cultures, alternative food sources, and novel foods. Psychological barriers to food acceptance may arise from prior beliefs and impressions about a target, and perceiving a mind in a target has been shown to influence ethical judgment. However, experimentally investigating food-related ethical themes using actual animals is difficult because of ethical constraints and the difficulty of controlling appearance and behavior.
To address this issue, the research group proposed an experimental framework using edible agents. Edible agents are artificial objects made from edible materials that can be designed and controlled in terms of appearance, movement, and vocalizations. The edible agent used in this study was based on a pneumatically driven edible robot previously developed by the research group. The edible part was made using gelatin, sugar, calcium carbonate, and 100 percent apple juice, and was designed with eyes and arms to support social interaction. A speaker placed under the edible agent played vocalizations, while compressed air caused the edible part to sway from side to side in synchrony with the audio.
To examine how people perceive such edible agents, the research group conducted an online survey using videos. Participants first watched a video showing how the edible part of the agent was made, which emphasized that it was made from familiar edible ingredients and could be eaten. They then watched two videos showing edible agents interacting with a person. In one video, the edible agent responded rationally to a person's concerns in Japanese. In the other video, the edible agent reacted to a hand and toys with baby-like vocalizations expressing joy, fear, anger, and sadness. Participants evaluated the edible agents using 18 mind-perception items and also rated their anticipated reluctance to eat and guilt if they were required to eat the edible agent.
The final analysis included responses from 1,094 participants. Factor analysis extracted two dimensions of mind perception: Agency, related to capacities such as self-control, morality, planning, and thought; and Experience, related to sensations and emotions such as joy, fear, pain, and rage. The edible agent that responded rationally was perceived as having higher Agency, whereas the edible agent with baby-like vocalizations was perceived as having higher Experience. These results indicate that different vocalizations and behaviors can modulate mind perception of an edible agent.
The study also examined the relationship between mind perception and anticipated reluctance to eat or guilt. Although different vocalizations and behaviors modulated mind perception of edible agents, no clear relationship was found between mind perception and either reluctance to eat or guilt. These results indicate that further studies are needed to clarify how mind perception is related to psychological responses associated with eating edible agents.
This study offers a new experimental tool for investigating human perception in human-food interaction and the psychological and ethical aspects of eating. Because edible agents can be intentionally designed and controlled in terms of appearance, movement, and vocalizations, they may provide a new way to examine issues that are difficult to study using real animals. Building on this framework, future studies should investigate human responses under more realistic conditions, including actual consumption and autonomous behaviors during eating.
Key contributors include:
Takuma Shimoyama (Doctoral student at The University of Electro-Communications)
Yuya Kume (Former master's student at The University of Electro-Communications)
Mei Yamagata (Assistant Professor at Doshisha University)
Hideyuki Takahashi (Associate Professor at Otemon Gakuin University)
