Longitudinal Changes in Component Processes of Working Memory

Abstract

Working memory (WM) entails maintenance and manipulation of information in the absence of sensory input. This study investigated the trajectories and neural basis of these component processes of WM functions in aging. Longitudinal human functional magnetic resonance imaging (fMRI) data are presented from 136 older individuals (55–80 years) who were scanned at baseline and again 4 years later. We obtained evidence that age-related changes in parietal and frontal components of the WM core network are dissociable in terms of their role in maintenance of perceptual representations and further manipulation of this information, respectively. Individual difference analyses in performance subgroups showed that only prefrontal changes in fMRI activation were accompanied by changes in performance, but parietal brain activity was related to study dropout. We discuss the results in terms of possible neurobiological causes underlying separable aging-related declines in inferior parietal cortex and lateral prefrontal cortex that differentially affect WM functions.

No metabolic “default mode” of human brain function

“…Whereas maintenance required only maintaining information in WM, the manipulation condition also required the active transformation of task information in WM. Robust fMRI responses to the task in canonical WM areas, FPN and DAN, have been reported in prior studies 74,75 . Prior to scanning, participants practiced four 1-minute blocks in each condition to ensure they fully understood the tasks.…”

Omega-3 PUFA metabolism and brain modifications during aging

“…However, a more recent study demonstrated that smaller hippocampus size is significantly associated with lower performance in episodic memory, working memory, processing speed, and executive function tasks 102 . Similarly to motor function, it has been shown that older adults recruit additional brain regions during memory tasks [103][104][105] .…”

Testing the influence of musical expertise on novel word learning across the lifespan using a cross-sectional approach in children, young adults and older adults

“…The aging human brain is characterized by grey (Crivello, Tzourio-Mazoyer, Tzourio, & Mazoyer, 2014;Jäncke, Mérillat, Liem, & Hänggi, 2015) and white (Bender, Völkle, & Raz, 2016;Hirsiger et al, 2016) matter changes in cortical (Crivello et al, 2014) and subcortical (Ziegler et al, 2012) brain regions. Such anatomical alterations are accompanied by an inter-individual variable decline of several cognitive functions (Shafto & Tyler, 2014), including attention (Erel & Levy, 2016;Fama & Sullivan, 2015), short-term memory, working memory (Rhodes & Katz, 2017;Rieckmann, Pudas, & Nyberg, 2017) as well as episodic memory (Fjell et al, 2016). However, due to compensatory functional mechanisms that are reflected by the recruitment of auxiliary brain regions or increased functional connectivity, there is no simple relationship between aging, brain changes and the preservation of cognitive functions (Shafto & Tyler, 2014).…”