The challenge comes in trying to figure about possiblities of ritual use. It seems in my view that much of our ritual and following of deities seemed to start for the most part after the last ice age-7-10000 years ago. But could it have something other than ritual? Something much simpler, a simpler version of understanding of self.
If we go back to the somewhat controversial Neanderthal era "mask"-which is still debated about whether it's just a natural rock formation or an actual piece of work-the question becomes blurry.
We do know that Neanderthals seemed to have some view of abstract thought-they buried their dead, often with tools and crafts as though to carry them to the next world, so certainly the mask in question could be ritual.
But what if it is a simpler question? What if the masks were made as a way of a "what am I?" construct. Perhaps they tried making masks and faces as a way of understanding, or trying to re-create themselves. Yet they would have looked at the mask and said "this is like me, but it is NOT me". Even today we try and recreate ourselves through computers, through art, and yes through masks.
It's such a challenge to say "they used masks to communicate with spirits", because we aren't totally sure what concept they thought of them.
As we see in later cave paintings of what are obviously humans wearing animal heads-it might (MIGHT) be easier that point to say there is ritual at the very least in the form of the hunting. And even then it's open to debate.
It's certainly an interesting idea to think that if Neanderthals a million years ago were already trying to sort out who they were in the world, and what made them what they were.
Certainly food for thought.