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Autobiographical memory research has largely focused on effortful, generative retrieval processes, particularly in cognitive ageing literature. However, recent evidence has shown that autobiographical memories are often retrieved directly, without effortful retrieval processes. In the present study, we examined the retrieval characteristics and the phenomenological qualities of directly and generatively retrieved memories in younger and older adults. Participants recalled autobiographical memories in response to word-cues and reported whether each of their memories was retrieved directly (i.e., memory popped into mind) or generatively (i.e., they actively searched for it), and provided ratings for several retrieval and phenomenological characteristics. Overall, directly retrieved autobiographical memories were recalled faster and with less effort, were more recent, more frequently rehearsed, more vivid, and more positive in valence than generatively retrieved memories. Importantly, while younger adults recalled a higher number of generatively retrieved autobiographical memories than older adults, there were no age effects on the number of directly retrieved memories. We also established the parallel-form reliability of the word-cue method in eliciting autobiographical memories by comparing two sets of word-cues. The results provide novel insights on the dissociable effects of retrieval type and ageing on autobiographical memories. Theoretical and practical implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

Self-knowledge is a type of personal semantic knowledge that concerns one's self-image and personal identity. It has most often been operationalized as the summary of one's personality traits ("I am a stubborn person"). Interestingly, recent studies have revealed that the neural correlates of self-knowledge can be dissociated from those of general semantic and episodic memory in young adults. However, studies of "dedifferentiation" or loss of distinctiveness of neural representations in ageing suggest that the neural correlates of self-knowledge might be less distinct from those of semantic and episodic memory in older adults. We investigated this question in an event-related potential (ERP) study with 28 young and 26 older adults while they categorised personality traits for their self-relevance (self-knowledge conditions), and their relevance to certain groups of people (general semantic condition). Participants then performed a recognition test for previously seen traits (episodic condition). The amplitude of the late positive component (LPC), associated with episodic recollection processes, differentiated the self-knowledge, general semantic, and episodic conditions in young adults, but not in older adults. However, in older adults, participants with higher composite episodic memory scores had more differentiated LPC amplitudes across experimental conditions. Moreover, consistent with the fact that age-related neural dedifferentiation may be material and region specific, in both age groups some differences between memory types were observed for the N400 component, associated with semantic processing. Taken together, these findings suggest that declarative memory subtypes are less distinct in ageing, but that the amount of differentiation varies with episodic memory function. [ABSTRACT FROM AUTHOR]