The frontal lobes are involved in motor function, problem solving, spontaneity, memory, language, initiation, judgement, impulse control, and social and sexual behavior.
TBI (traumatic brain injury) in this erea can cange your behavior, cause loss of fine movements and strength, loss of spontaneous facial expressions, difficulty in speaking and in the formation of verbal abilities, impaired associated learning, decision making, difficulty in interpreting feedback from the environment - these are only part of the "negative effects" that frontal lobes brain damage can cause.
I think the puzzle solving is a negligible good effect..