I don’t know what “directly” means, but there certainly is a causal pathway, and we can certainly evaluate whether our brains are tracking reality. Just make a prediction, then go outside and look with your eyes to see if it comes true.
Inasmuch as you are looking with your eyes, that would be tracking appearance. What you don’t have is a way of checking whether the ultimate causes of your sense data, in reality, are what you think they are.
Inasmuch as you are looking with your eyes, that would be tracking appearance. What you don’t have is a way of checking whether the ultimate causes of your sense data, in reality, are what you think they are.