that the number of brain synapses increased when the test rats ran mazes. In the 1990s research into neuroplasticity abounded. Studies revealed that adult mice living in “enriched” environments involving mental challenges produced additional cells in the brain’s hippocampus. Also, researchers with monkeys and then with humans demonstrated that “enriched” environments increased brain cells. This indicated neuroplasticity. Furthermore, researchers proved that intellectual abilities are modifiable. In addition,