Dreams are not meaningless,___during dreams brain produces new ideas.

The correct answer to the question "Dreams are not meaningless,___during dreams brain produces new ideas" is "Instead". This means that dreams are not without purpose or value, and they actually serve the function of producing new ideas. The word "instead" is used to contrast or compare two ideas, and in this case, it suggests that the belief that dreams are meaningless is incorrect, and that the real function of dreams is to generate creative ideas. Therefore, the correct statement is: Dreams are not meaningless; instead, during dreams, the brain produces new ideas.