Early selection versus late correction: Age-related differences in controlling working memory contents.

Abstract

We examined whether a reduced ability to ignore irrelevant information is responsible for the age-related decline of working-memory (WM) functions. By means of event-related brain potentials we will show that filtering is not out of service in older adults but shifted to a later processing stage. Participants performed a visual short-term memory task (change-detection task) in which targets were presented along with distractors. To allow early selection, a cue was presented in advance of each display, indicating where the targets were to appear. Despite this relatively easy selection criterion, older adults’ filtering was delayed as indicated by the amplitude pattern of the contralateral delay activity. Importantly, WM-equated younger adults did not show a delay indicating that the delay is specific to older adults and not a general phenomenon that comes with low WM capacity. Moreover, the analysis of early visual potentials revealed qualitatively different perceptual/attentional processing between the age groups. Young adults exhibited stronger distractor sensitivity that in turn facilitated filtering. Older adults, in contrast, seemed to initially store distractors and to suppress them after the fact. These early-selection versus late-correction modes suggest an age-related shift in the strategy to control the contents of WM.

Contralateral delay activity is not a robust marker of cognitive function in older adults at risk of mild cognitive impairment

“…CDA amplitude was calculated by subtracting ipsilateral from contralateral activity from 350 to 850 ms following the onset of the memory array at three posterior electrodes (P5/P6, PO7/PO8 and CP3/CP4). The time window selected was based on previous studies (Newsome et al, ; Schwarzkopp et al, ). Electrode selection was based on Newsome et al ().…”

“…Some studies have shown that older adults exhibit reduced differentiation of CDA amplitudes across set sizes relative to younger adults, suggesting that the CDA is sensitive to age‐related cognitive changes (Sander, Werkle‐Bergner, & Lindenberger, ; Stormer, Li, Heekeren, & Lindenberger, ). However, other studies have failed to find differences in CDA amplitudes across older and younger age groups (Jost, Bryck, Vogel, & Mayr, ; Schwarzkopp et al, ).…”

“…The CDA waveform is therefore thought to provide an online index of WM processing (Feldmann‐Wüstefeld, Vogel, & Awh, ). In recent years, the CDA has become increasingly popular as a marker of age‐related WM decline (Du, Ji, Chen, Tang, & Han, ; Schwarzkopp, Mayr, & Jost, ; Wiegand et al, ). Some studies have shown that older adults exhibit reduced differentiation of CDA amplitudes across set sizes relative to younger adults, suggesting that the CDA is sensitive to age‐related cognitive changes (Sander, Werkle‐Bergner, & Lindenberger, ; Stormer, Li, Heekeren, & Lindenberger, ).…”

Contralateral Delay Activity is not sensitive to cognitive decline in older adults at risk of Mild Cognitive Impairment

“…The CDA has become increasingly popular as an index of age-related WM changes (Du, Ji, Chen, Tang, & Han, 2018). However, existing evidence regarding the effects of both age and performance level on CDA amplitudes is equivocal (Jost, Bryck, Vogel, & Mayr, 2011; Sander, Werkle-Bergner, & Lindenberger, 2011; Schwarzkopp, Mayr, & Jost, 2016; Stormer, Li, Heekeren, & Lindenberger, 2013). One possible explanation is that atypical CDA waveforms reflect pathological decline, rather than normal aging.…”

Negative Affect Influences Electrophysiological Markers of Visual Working Memory in Mildly Stressed Older Adults

“…Specifically, detrimental aging effects were found to be most prominent in earlier time intervals of the CDA, which is thought to represent the selection and encoding of visual information (Yamaguchi et al, 1995 ; Gazzaley et al, 2008 ; Jost et al, 2011 ; Störmer et al, 2013 ). Schwarzkopp et al ( 2016 ) explored these age-related differences alongside filtering efficiency (FE), the ability to filter out irrelevant stimuli whilst maintaining the relevant, and suggested that older adults rely on the earlier CDA interval to filter out irrelevant information; whereas, younger adults did so much earlier in time via sensory selection processes. These results indicate that there may be a fundamental dissociation between functional processes and overall performance in working memory as people age.…”