And yet it sounds a lot like "capturing the mind", which is how I was taught "aiki" operated. I can see you mean something different, whereas this "aiki" I was taught had more to do with manipulating perception. In any case it is confusing that the term aiki is used differently in different aikido circles. That includes the "spiritual" takes. I suppose I'm just making things more confusing than not.
How is this all related to 6 directions in internal training, and how this can be part or not of aikido?
I learned kurai dori was taking the mind. Not aiki, but a building block of it. I also learned musubi was connecting to your partner. Not aiki, but a building block of it. Both can be done to a level of skill as to express similar properties to aiki. I think the aiki I am starting to identify is not these things, although these things are expressed in aiki. So is kuzushi. It's like I need a ven diagram or something.
Cady and Hugh have some great comments. I think the big difference in 6 directions is that that training is not dependent on a partner. Meaning that my ability to self-sustain my stability is the key component. Many aikido exercises actually require a partner. For example, kurai dori requires another mind to capture (take). Musubi requires a partner with who to be connected. Let alone the mental shift from doing something to someone to being someone.
So 6 directions for me has taken on a solo exercise feel; even if my partner is testing my stability, i am not creating a relationship with her. We have started changing our training to establish our stability first, then worry about musubi, kurai dori, kuzushi. So it is aikido, but we just have to make room for it in our training.