Memory research is interesting exactly because of the way we remember things – even the way we remember the remembrances of the Gospels. I believe that such science can help us even in understanding how the Gospels shaped the early memory of Jesus and were themselves shaped by the early memory of Jesus.
Some aspects of the memory can endure a long time, while others are more fickle. “The memory of a romantic first meal out with a partner may take on a different mood when the relationship falters,” said Tomonori Takeuchi and Richard Morris at the University of Edinburgh, in an article accompanying the study. “In these cases, memory of the place remains accurate, but the positive associations with that place are lost.”
In short, I believe the monumental act of the written Gospel forever changed the historical memory of Jesus, even among those who may have actually known him (although by this time, it would have been very few).