Although we believe these two factors represent the most parsimonious explanation for the present results, we cannot rule out the potential contribution of age-related changes during encoding. Indeed, an important challenge associated with explicit memory tests is the difficulty of separating contributions of processes operating during encoding to the resulting quality of stimulus representations. For example, it is possible that older adults are more likely than younger adults to preferentially focus on semantic as compared with perceptual object information during encoding, thus reducing the availability of perceptual details at test and increasing reliance on semantic gist (Brainerd & Reyna, 2002; Koutstaal et al., 1997, 2003). Although we tried to minimize this possibility by using a perceptually oriented encoding task to encourage comparable processing of images by older and younger adults, it is difficult to completely rule out when concrete, meaningful objects are used as stimuli. Nevertheless, existing evidence argues against the idea that age differences during encoding, and in particular a tendency to predominantly focus on semantic information at the expense of perceptual detail, can account for the pattern of results presented here, as elaborated below.