The vulnerability of memory as a function of age
Perhaps the most dramatic age-related change in memory function in infancy is in the length of time over which memories are retained. The changes indicate decreases in the vulnerability of memory traces with age. Based on performance on imitation-based tasks, described earlier, the length of time over which infants retain memories of specific past events increases over the first two years of life. As suggested by inspection of Fig. 1, in the first year, retention is limited to hours and days, whereas by the end of the second year of life, infants remember novel experiences over delays of 12 months or more (Bauer et al., 2000; see Bauer, 2009, 2013, and Lukowski & Bauer, 2014, for summaries). These data lend themselves to interpretation in terms of differential forgetting: there is greater vulnerability of memory in younger relative to older infants, resulting in age-related differences in how long memories are retained.