One day while gardening, Greg tripped over a coil of wound-up hose and fell face first on the pavement. He suffered damage to his hippocampal region, and while recovering in the hospital, he consistently greeted his friends and family as though he was seeing them again for the first time in a long time. Greg often forgot what he was doing during the day. However, he could still recall, without effort, adventures from his teenage years. MOST likely, Greg has what would be called ____