Hmmm,
not sure Mark as I haven't expereinced any deficiencies with my two guys yet,
that I'm aware of.
However some of the symptoms I can say both display to some degree.
Bubba's sight and hearing are definitely out the door. I will sometimes find him
standing in a room not sure which way to go and it has happened in the backyard too!
I have to go and rescue him along.
I put it down to his sight..... I think in certain "lights" it is harder for him to see and
he is not sure what is ahead of him. I can go out and call him and if I nudge him in the right direction
and let him know that it is okay..... he will happily follow me. He recognizes my voice so I don't think that
is cognitive dysfunction.
Bubba will also bark at the gate whether anything is there or not and sometimes lately he has been barking at nothing in the house?!?!? again his hearing is going so I think, he thinks he is hearing something and
just wants to make me aware cause as soon as I let him know there is nothing there he is quiet again!!!
again he recognizes my voice and when he hear sit he is quiet.
There have been times where I know he did not hear and times where he has, so for me I think it is on and off, comes and goes at this point?!?!?
As for the crying, I am experiencing that with Pugsley right now and it is heart wrenching but he is trying to let me know he needs something and we go through the rote:
outside for a pee or dump, inside try some food or yogurt, try some water and then the cuddle session.....
I used to be able to ask him what he wanted and Pugsley was super he would give a shrug on something I would rhyme off but not now

Not sure if this helps out or not........ but your Vet will know for sure if it is cognitive failure.......