The Functional Foundations of Episodic Memory Remain Stable Throughout the Lifespan

Abstract

It has been suggested that specific forms of cognition in older age rely largely on late-life specific mechanisms. Here instead, we tested using task-fMRI (n = 540, age 6–82 years) whether the functional foundations of successful episodic memory encoding adhere to a principle of lifespan continuity, shaped by developmental, structural, and evolutionary influences. We clustered regions of the cerebral cortex according to the shape of the lifespan trajectory of memory activity in each region so that regions showing the same pattern were clustered together. The results revealed that lifespan trajectories of memory encoding function showed a continuity through life but no evidence of age-specific mechanisms such as compensatory patterns. Encoding activity was related to general cognitive abilities and variations of grey matter as captured by a multi-modal independent component analysis, variables reflecting core aspects of cognitive and structural change throughout the lifespan. Furthermore, memory encoding activity aligned to fundamental aspects of brain organization, such as large-scale connectivity and evolutionary cortical expansion gradients. Altogether, we provide novel support for a perspective on memory aging in which maintenance and decay of episodic memory in older age needs to be understood from a comprehensive life-long perspective rather than as a late-life phenomenon only.

Hippocampal-cortical functional connectivity during memory encoding and retrieval

“…Approximate guessing rates for each individual was estimated by the number of incorrect answers to Q3, as the participants had indicated that they remembered the association in Q2, but then chose the wrong answer. These were subtracted from the number of correct answers before calculating the recollection index to correct for guessing (Sneve et al, 2015; Vidal-Piñeiro et al, 2021). The task presentation was controlled with E-Prime 2.0.…”

“…In case of 'No' answer to either Q1 or Q2 the trial ended without further questions. For memory analysis, a recollection index was calculated, correcting for guessing, by subtracting the number of incorrect answers to Q3 from the number of correct answers to Q3 6,55 . The recollection index, presented as the percentage of all trials, was 44% (sd = 19%).…”

Integration of GWAS and brain transcriptomic analyses in a multiethnic sample of 35,245 older adults identifies DCDC2 gene as predictor of episodic memory maintenance

“…As we age, our cognitive abilities deteriorate, 1 without necessarily progressing to dementia. One of the earliest and most striking cognitive changes in the aging process is the alteration of memory.…”