Did you visit your grandmother to the glory of God?
I said it was degree referring to the corruption of man. When Adam sinned, he could still think, he had emotions, and could exercise his will. But he couldn't do so as he did before. This isn't hard to demonstrate. He felt shame for the first time, he felt fear for the first time, he hid from God for the first time, he made clothing for the first time, and he blamed God for the first time. Something was terribly different. But all those things testify that his mind was still working, his heart was still functioning, and his will was still evident.
Doing good is a related issue, but it doesn't evidence total corruption of Adam as you suppose. Rather, it reflects that his capacity due to the effects of sin render him incapable in and of himself to do good. His heart which was once towards God is now desperately wicked and deceitful above all things. The center of man's being has been corrupted which is the wellspring of his life. He can still be moved by his emotions, but his emotions have been corrupted. Before sin, his emotions were love and peace and joy. After, shame and fear. Later we find both anger and depression with Cain. Man is no longer good.