Effects of self-paced encoding and practice on age-related deficits in binding three features.

Although much literature suggests that the age-related decline in episodic memory could be due to difficulties in binding features of information, previous studies focused mainly on memory of paired associations rather than memory of multiple bound features. In reality, however, there are many situations that require binding multiple features together simultaneously. Thus, this three-part experimental study using a working memory task examined two fundamental questions: whether and how well older adults perform a working memory task that requires them to bind three features together (Experiment 1), and whether and how much older adults' memory of units of three bound features could be improved by self-paced encoding and 3 weeks practice (Experiments 2 & 3). The results indicated that although older adults performed as well as young adults in remembering one unit of three features, they showed a deficit in remembering two units, making more severe errors than young adults, and the difference between the two age groups increased when remembering three units. However, older adults improved their memory performance substantially by two means: self-paced encoding and practice. The former primarily shortened reaction times while the latter primarily improved memory accuracy. With self-paced encoding, older adults were also capable of binding at least three units during encoding. Thus, it is possible to assume that under an optimal encoding period, the age-related deficits occur probably not at encoding but at retention and/or retrieval.