I'm of Two Minds on This
Or maybe three. But definitely not one. It's an exercise I find myself doing
a lot as I work on things that challenge me: trying to get my mind -- not just
my limbs -- to focus on two things at once.
An exercise that Thomas Lang recommends is to vary the volume of your limbs
one at a time. This gives you better control over dynamics. But more
importantly, it forces you to focus your attention on one part, then another
part, then another part. It's physically challenging, but mentally it can be
even more taxing. As you move your focus from limb to limb, you are also
compartmentalizing the other limbs. And that's what I mean by two minds: one
'mind' is concentrating on the bass drum pattern while the second keeps the
cymbal, snare and hi-hat moving along.
I often find that, when I'm having trouble with a pattern, it's often because I'm not thinking about it the right way. For example, the bass drum may suffer if I’m thinking mostly about the snare part. Sometimes I'll think I have a pattern and then discover that I only have the mechanics, and that it falls apart if I'm momentarily distracted. I need to focus more consciously to over-come this obstacle.
So my objective is to control all the parts mentally as well as physically. For example, I'm trying to play different bass drum patterns while working through some lines in Stick Control. Some come quite easily and others take a bit more work. But some of them stubbornly refuse to fall into place. Even when I can execute them, I sometimes find that I'm thinking pattern rather than rhythm. That tells me that I don't own it -- I can merely execute it.
Here’s a test case. While playing this line, try to see your limbs as different teams: Feet vs. hands, left hand plus bass drum, right side vs. left side, feet only, etc. The goal is to hear the separate parts as separate 'players'.
As always, no real answers for you. I highly recommend that you work on
moving your attention around the set using the Thomas Lang exercise. Focus on up
and down, and left and right, concentrate on what your hands are doing while
ignoring your feet, etc. Also pay attention to both the pattern and the rhythm.
And if you can't tell the difference, you've arrived.