Final answer:
In Ken Kesey's novel, Bromden notices a significant change in McMurphy as they return from a trip, indicating that McMurphy has been affected by the oppressive atmosphere of the mental institution.
Step-by-step explanation:
In Ken Kesey's novel One Flew Over the Cuckoo's Nest, Chief Bromden notices a significant change in McMurphy on their way back from a trip.
While McMurphy was once loud and disruptive, he now appears calm and subdued.
This change is significant because it indicates that McMurphy has been affected by the oppressive atmosphere and control of the mental institution.
It suggests that McMurphy has lost some of his rebellious spirit and is conforming to the system, which ultimately leads to tragic consequences.