Age differences in hypermnesia: word gain versus word loss

A hypermnesic task was administered to 82 younger adults (ages 27-39), 63 middle-aged adults (ages 40-59), and 119 older adults (ages 60-87). Previous research suggests that relational encoding prevents loss of items and item-specific encoding promotes item gains in a hypermnesic task (Klein et al., 1989) and that there are age differences in relational but not item-specific encoding (Luszcz et al., 1990). This information provided the basis for three predictions: (a) There are age differences in hypermnesia, (b) there are age differences in word losses in a hypermnesic task, and (c) there are no age differences in word gains in a hypermnesic task. In order to manipulate type of encoding, a list of words with high association strength (to evoke relational encoding) and words with low association strength (to evoke item-specific encoding) was constructed. The results of this investigation provide support for the encoding manipulation and for all three predictions. In addition, the nature of the age differences in word loss observed suggests that although older adults may be capable of relational encoding, this form of encoding is not as effective at preventing word loss for them as it is for younger adults.