I would guess the main driver for brain stimulation is the coordinative aspect of dealing with many motor skills over different body parts doing different things, while also coordinating the rhythms and cadence of music in your mind. So the more coordinated the movement (ballet, flamenco), the more stimulated. There's also the component of memorizing sequences. In this respect, yoga is also very fruitful. Many traditional yoga teachers say that yoga makes you more intelligent.

As a personal experience with ballet for over 5 years (starting in mid-twenties with no prior dance experience, and taking up other modalities later), it has completely reorganized my mind; now I have a strong and reliable memory for body movement, now I have a durable sense of sequentiality that I apply to everything I do (the gains are most apparent when doing many chores, cooking, getting ready for an overseas trip, etc), so that my consciousness is well ordered and doesn't get confused with simultaneity of inputs, but knows how to prioritize easily and without my ostensive effort. It's a bit like having trained a highly capable assistant that now takes over for many tasks that would previously leave my head dizzy with an influx of urgent demands.

Some of this applies to music and learning an instrument, especially not a woodwind, melody-only on, but a coordinating instrument like piano or other strings, especially if you are singing on top of the harmonny. Both dance and music are fundamentally about harmony, in dance you harmonize your body parts relative to each other and to the dance, and in choreographies like ballet, even more so to the other dancers, requiring exacting precision and balance.

Yoga and the classic dances are hard stuff, taxing the mental faculties. It may only not seems so outwardly because so many natural dancers start from early ages, and like learning a language, any mildly talented person starting so early will achieve ease eventually. But building that ease for late starters is much tougher than, say, programming a single page app, if I may be so bold.

> "I would guess the main driver for brain stimulation is the coordinative aspect of dealing with many motor skills over different body parts doing different things, while also coordinating the rhythms and cadence of music in your mind. So the more coordinated the movement (ballet, flamenco), the more stimulated."

Interesting that you mention flamenco [1]. I started dancing flamenco 8 years ago, at age 42. I am a late starter to dance, which is a polite way of saying I actively avoided it for most of my life.

When I started, I could barely put together a half-dozen steps. And if I tried to add arm, hand or head movements, my feet went out of time. My brain just didn't feel big enough There was no way I could remember even a tiny section of a choreography like this one I link to from Marco Flores.

Yet as I got more experienced, my brain gradually adjusted to think of body movements as integrated flows, not individual motions. It learnt how to "chunk" them together into logical sequences, and how they align to a piece of music. Much to my surprise, I can now remember complex choreographies several minutes long.

My next challenge is to internalize all of this, so I can relax and dance more comfortably. Maybe I'll never get good enough to improvise dancing with a guitarist and singer. But looking back, I am thrilled how far I've come.

[1] Since few people here will be familiar with flamenco, here is a clip of Spanish dancer Marco Flores performing a Seguiriya: https://youtu.be/ajVmaj6Z93o?t=397.

Notice how Marco beats out what appears a chaotic rhythm with his feet, yet it keeps coming back to the strict beat clapped out by the singer. If you try to follow along, note the rhythm here has a 5-beat bar: 1-and, 2-and, 3-and-a, 4-and-a, 5-and. So the 1, 2 and 5 are short, and 3 and 4 are long.

Hey! Yes, flamenco is well considered a complex musical instrument of percussion, much like a Jazz drummer could make complex patterns and improvise. Hope we get to dance together someday on some improvised street somewhere in the world! The great thing about flamenco is that, even though it's almost or quite involved like ballet (the national ballet in spain trains top ballet dancers to combine flamenco dance in choreographies), it's something you can start much later and also have a longer career into your seniority (keeping your wits about and Alzheimer's well away).

Also, some versions of the opera Carmen has almost an hour-long flamenco part, it's worth watching, a good french opera.

The authors of the studies seem to believe that the "combination of physical activity and sensory enrichment" and “cognitive and coordinative demands” are the key ingredients.

If this is the case then the results should also generalise to sports, which have an aspect of sensory enrichment and coordinative challenge.

But I agree with you, it would be very interesting to actually find out what the “key ingredients” are. Especially since dance is so diverse and difficult to define. In fact, I think the category of dance can be best described using Wittgenstein's concept of family resemblance. There is not one essential common feature between all forms of dance, instead there are a lot of overlapping aspects.

It's only different for sports because all the coordinating (like of old the activites of hunting and war) applies to a single focus, the body is all maneouvered to the same mind state. In dance, you have to coordinate subtle muscles in precise ways. In sports, the precision is about the particular result you want (a stroke, a kick), but in dance, there are many goals and you need to mind whether your thigh muscle is holding up in just the proper, beautiful way, because the teacher and a knowing audience can tell, much like in musical performances, whether you are really achieving the coordination or faking, or being a beginner. The coordination in dance is of several (and I mean tens of body parts or muscles at the same time) parts having different purposes (supporting the movement, getting balance, showing off, giving impulse, etc) and the brain having to watch them all, all at once. It's much harder to dance beautifully than to swim or run or jump and throw a basketball beautifully, because in dance aesthetics is the primary source of goals for all those body parts, they have different roles or different relationships to the same melodies and harmonies playing over the dance.

May I ask what the “plant study” you are referring to is?

Sorry for not being more clear, I meant Langer's classic study. A critical/write-up here:

https://www.coyneoftherealm.com/2014/11/05/re-examining-elle...

Langer gave houseplants to two groups of nursing-home residents. She told one group that they were responsible for keeping the plant alive and that they could also make choices about their schedules during the day. She told the other group that the staff would care for the plants, and they were not given any choice in their schedules. Eighteen months later, twice as many subjects in the plant-caring, decision-making group were still alive than in the control group. To Langer, this was evidence that the biomedical model of the day — that the mind and the body are on separate tracks — was wrongheaded.