dACC

"great faith, great doubt, and great determination"

during zazen, you have plenty of reasons to stop. your knees hurt, sitting might even be damaging them. sitting is making your anxiety worse. you could be using the time for something productive. you're doing the wrong thing with your mind and it's creating bad habits. you realized that the philosophy and practice were designed for japanese people and don't make sense for you. you had an important insight about yourself that's going to really help in your life, and you need to think about it, write it down, not forget about it.

this is like the demon mara trying to distract the buddha with his sexy daughters. mara says, "What can you do by struggling now? The path of struggling is too rough and difficult and hard to bear."

parts of your mind say you should quit, because you don't have a path to your goal. this is frustration. when it's really strong, hopelessness or despair.

but with a broader goal, you stay determined and keep sitting. two ideas:

1) this sounds like a function of the dorsal ACC. (it must also be related to, in a xiao-jing wang-esque sense, how neuronal ensembles with long time scales are important for higher and more human cognitive function. and maybe to decoupling gilbert's "nexting" from "imagination".)

the system including dACC feels like it's still making progress toward goal, because it has this meta-stable long-term goal/belief representation.

2) so far, this could apply to anything you stay determined to because you have a broader goal. maybe you persevere with studying because you want a degree, or persevere with running because you want to be fit.

but something about zazen could be that any of these goals themselves ultimately end in frustration when they're faced with their own partiality. if you keep sitting through everything, it can't be put down to a particular broader goal. it could be continually relaxing into broader and broader goals, like poetry. in the brain, maybe this is training dACC in a context-free way - just training the essence of perseverance itself, free from any particular content.

i guess this is like passionate equanimity again. the "passionate" is being absolutely determined, and the "equanimity" is the willingness to allow any formal content to be part of the process.