I stopped to see Matt on my way home. He was awake and had both eyes open. I talked to him for a few minutes, and said that maybe Morse code might help. He blinked a few times, but it wasn't clear that he understood. Then a couple of nurses came in and we (Roger, his father, and Elise, his daughter) had to vacate the room.
When we came back, he was asleep.
Significant things I saw or heard today.
Elise said he smiled a little.
I saw him move his thumb to open his grip and, when I said "can you close it?", he did.
Roger said that, when he moved to the other side of Matt's bed and said, "Matt", he turned his head. He did this twice, and I think that's significant.
His temperature has been normal for a couple of days. Hopefully, they will replace the piece of his skull that's missing, and he will be moved out of Intensive Care in a few days.