Can the elderly benefit from unitization? – Effects of different unitization manipulations on age-related associative memory deficit

With the aging process, older adults performed significantly poorer than young adults at remembering the relationships between pieces of information. This phenomenon is known as age-related associative memory deficit. Associative Deficit Hypothesis posits that this deficit stems from hippocampal atrophy in older adults, leading to a decline in their ability to bind information and an impairment in hippocampus-dependent recollection. Fortunately, unitization is a strategy that not only promotes information binding but also promotes familiarity to support associative memory. This study systematically examined the effects of different unitization manipulations on this deficit through three experiments. Experiment 1 revealed that the influence of bottom-up unitization on associative memory was modulated by changes in level of unitization, but its moderating effect on the relationship between unitization and age-related deficit was not significant. Experiments 2 and 3 indicated that, compared to the concept definition task, which exacerbated age-related deficit (Experiment 2), the top-down unitization with interactive imagery task could alleviate this deficit (Experiment 3). When estimating the contribution of familiarity and recollection to associative memory, the three experiments consistently revealed that, compared to young adults, older adults demonstrated significantly reduced recollection, while familiarity remained relatively intact, as well as that unitization could promote familiarity to support older adults' associative memory. In summary, the current study has systematically examined the impact of different unitization manipulations on age-related associative memory deficit, and provided some experimental evidence for interventions to alleviate such deficit.