Original sentence: In psychology, bicameralism is a hypothesis which argues that the human brain once assumed a state known as a bicameral mind in which cognitive functions are divided between one part of the brain which appears to be "speaking", and a second part which listens and obeys
Edited sentence: In psychology, bicameralism is a controversial hypothesis which argues that the human brain once assumed a state known as a bicameral mind in which cognitive functions are divided between one part of the brain which appears to be "speaking", and a second part which listens and obeys