Once controlled research studies were conducted on the effectiveness of prefrontal lobotomies, they were discovered to be

Uncle Waldo is trying to play "peek-a-boo" with his young nephew by hiding behind a blanket. Every time Waldo goes to hide, he waits and then has to look for his nephew who never moves. If Waldo's nephew could talk, what might he say?

a) "What are the rules of the game?" b) "I wonder why Uncle Waldo keeps disappearing." c) "What an egocentric way of thinking about the world." d) "Most adults think children like these games, but we don't."

The more you engage in a particular type of cognitive activity, the more the brain structure that controls that activity will develop and grow. This demonstrates the concept of synaptic __________

a. genesis. b. flexibility. c. plasticity. d. reversibility.