In the late 1960s at the University of California, Berkeley, biological psychologist Mark Rosenzweig and neuroanatomist Marian Diamond engaged in an experiment that was pivotal to the field of neuropsychology. They placed rats in different environments (or “niches”) for an extended period of time. Some of the rats were in “enriched environments” consisting of large cages with stimulating activities such as mazes, ladders and wheels. Other rats were put into less enriching environments where they were either alone or with only one or two cage mates and no available stimulation.
After several weeks, the brains of the rats were dissected and studied. Rosenzweig and Diamond discovered that the rats in the enriched cages had more synapses, or brain connections, than those in the less stimulating cages. It turns out that the environmental experiences of the rats directly changed their brain structure.
via "Your brain is a rain forest" (odewire.com)
Unlike rats, we can control the environments we're in. Surely controling our own environments to create the most enriched possible space makes sense. To construct one's own life less as a cage and more as a playpen.