Answer:
Assimilation process.
Explanation:
One of Jean Piaget's most famous theories is his theory of cognitive development, in which he formulated four different stages in brain development. He came up with this to come up with a theory that would explain a child's overall development.
According to this theory, cognitive development occurs through assimilation and accommodation. At the assimilation stage one builds mental assimilation schemes to approach reality. Thus we can conclude that Jane was creating a scheme of assimilation between the relief that the mattress provides to her back and the relief that the mattress may provide to her knee.