Simulating a Human Fetus in Soft Uterus

Behavioral studies suggest that human cognitive development begins in the early developmental stage. However, owing to technical and ethical difficulties, there is limited knowledge on how embodied interaction contributes to early human development. Accordingly, constructive approaches for deepening the understanding of cognitive development are gaining attention in developmental robotics and dynamic systems. In this study, we performed a biologically plausible simulation of early human development, by updating the fetal simulation model that was developed in our previous study including a musculoskeletal body and uterine environment model. First, we updated the dynamics of the joints and muscles. Furthermore, we developed a new method to create soft objects of the desired shape in a rigid body simulator to achieve a soft uterine model. Subsequently, in a new simulation, we examined the impact of the soft uterine environment on the tactile experiences and subsequent cortical learning, compared to the extant uterine model and extrauterine environment. We observed that the soft uterine environment provided frequent and varied tactile information, which facilitated cortical learning toward achieving a higher cortical response to sensory inputs. Furthermore, we demonstrated that the embodied structure induced by the tactile sensor arrangement was crucial for cortical learning. Because actual fetuses and infants participate in flexible interactions, the proposed simulation using the soft environment could illuminate developmental care in the medical field.