It depends. Is there such a thing as sound?
In the external reality, there are quarks. My body is a particular set of (continually replaceable) quarks that more-or-less obeys my mind; besides, my mind has privileged access to the sensory inputs of this body, so it's justified to consider it as distinct from the rest of reality. A category like "thumb" is a shortcut entry that is very useful to refer to a subset of quarks that stay in a very specific, more-or-less constant configuration.
So, does my thumb exist? Yes, in the sense that a bird flock exists because some of them fly together.
Let's say we're talking about the source code of reality.
You and I seem to agree we could start somewhere like "var quarks = [...]".
My position is that there is no "flockofbirds" or "var polymathswannabe_thumb = "
Those a purely made by the mind.
Likewise, in reality, there is no "brain" or "brainstem" or "frontallobe", there is just "var quarks = []".
The brain is a product of a mind.
I did a search about property dualism and I couldn't see much written here on this site.