Unitization Based Memory Enhancement in Younger and Older Adults

Memory for episodic associations declines with ageing due to decreased recollection abilities. Unitization-the encoding of multiple items as one integrated entity-has been shown to support familiarity-based retrieval that is independent of recollection and is relatively preserved in healthy ageing. Accordingly, unitization has been proposed as a promising strategy to attenuate age-related associative deficits, but evidence regarding its utility was lacking. The current study aimed to establish unitization as a viable mnemonic strategy. First, to ensure that unitization can attenuate the age-related associative deficit for initially unrelated materials, top-down unitization was used. Namely, participants were given an initially unrelated word pair in the context of either a definition which allows the words to be encoded as a unitized compound or a sentence in which the words are encoded as separate entities. Second, to ensure that unitization can be used as a self-initiated strategy, participants also completed the task by generating their own binding information (definitions/sentences). As expected, a unitization effect had emerged, such that associative memory was enhanced following definition encoding. However, this effect only occurred when binding information was provided. Additionally, a general memory advantage for the self-generation condition had emerged, but this was (generally) similar across unitization conditions and age groups. Taken together, the results show that unitization can be used as a mnemonic strategy under certain conditions, and highlight additional steps that should be taken before it can be effectively used beyond lab settings.