Officials at the hospital in central Budapest, where the Brazilian was transported after his frightening qualifying incident last Saturday, said Massa had responded when once again roused from his induced coma.
The 28-year-old did not speak but made "passive communication" with doctors, and also moved his hands and feet.
Another brain scan showed positive signs, the officials added, and an ultrasound revealed "nothing that would give cause for concern" with regards to internal injuries.
"These are definitely positive signs," the hospital's Istvan Bocskai told Hungarian state television.
Rubens Barrichello was gravely concerned for his countryman and friend after Sunday's Hungarian grand prix, but a subsequent visit to the hospital that evening gave him reason to leave Budapest "in peace".
It also emerged on Monday that the official investigation into the accident will be conducted jointly by the FIA and Brawn GP, after the 800 gram damper spring that struck Massa on his helmet fell off Barrichello's BGP001 car.