When our adventure began, Fritti and Ryder had no memory of one another, their old party members, Unknown, or any of the events directly leading up to their confrontation with the beholder. Their memory loss was tied to the people involved in the battle rather than simply being a chunk of lost time. For example: if they had visited a produce merchant together, they would have been able to remember speaking with the merchant, but not that they were there together.
Seeing pictures or items given to them by their old friends sparks emotions, but not memories - like a smell that reminds you of something you can't quite recall. Looking at or focusing on these objects for too long, however, causes an intense head pain that doesn't stop until the stimulus is removed.