One of the most consistent ways research has demonstrated to increase connectivity in the brain is to learn new physical skills. Controlling the body in space appears to be particularly good at stimulating the growth of new synapses (and possibly new neurons as well, though the research is not conclusive here outside the hippocampus). Yoga is a good start. Modern dance, breakdancing, capoeira and gymnastics are all e…
The more literature I read about this, the more compelling I find this. In mammals, the larger the body the larger the brain. That's because you need all those neurons to control all those muscles. I recently read some papers that hypothesize the muscle atrophy we experience as we get older is partially the result of the neurons controlling those muscle-fibers dying [1]. As infants, our brains grow into our bodies by producing more neurons than we need and then killing off the neurons that aren't being used [2]. It makes sense to me that if we don't use our bodies in a variety of exercises, the lack of signal from the muscles to the brain could result in pruning those neurons as we get older.