Temporally-graded retrograde amnesia (TGRA) refers to a phenomenon of premorbid memory loss whereby information acquired recently is more impaired than information acquired more remotely. Studies of human amnesia have illuminated this phenomenon (Hodges, 1994; Squire and Alvarez, 1995), but such studies necessarily rely on retrospective methods and imperfect tests. Studies in experimental animals have the advantage that retrograde amnesia can be studied prospectively, the locus and extent of brain lesions can be determined accurately, and the timing and strength of original learning can be precisely controlled. The socially transmitted food preference (STFP) task has been one of the most productive rodent behavioral tasks to study TGRA (Clark et al., 2002).