There are different forms of cognitive therapy.

After having a neuro-psych exams to identify my deficits, I was sent for Attention Processing Training (APT). Over a number of months, I worked through tasks designed to increase my focus and processing speed. I found it very useful. It's not a "cure," but it helped me maximize what I've got left.

As for conversation, it does require a lot of cognitive effort. In addition to challenging our ability to concentrate and process information, many of us face the additional hurdles of aphasia and apraxia. I would still rather write an email, than talk to someone.