Retrospective attention enhances visual working memory in the young but not the old: An ERP study

Abstract

Behavioral evidence from the young suggests spatial cues that orient attention toward task relevant items in visual working memory (VWM) enhance memory capacity. Whether older adults can also use retrospective cues (“retro-cues”) to enhance VWM capacity is unknown. In the current event-related potential (ERP) study, young and old adults performed a VWM task in which spatially informative retro-cues were presented during maintenance. Young but not older adults’ VWM capacity benefitted from retro-cueing. The contralateral delay activity (CDA) ERP index of VWM maintenance was attenuated after the retro-cue, which effectively reduced the impact of memory load. CDA amplitudes were reduced prior to retro-cue onset in the old only. Despite a preserved ability to delete items from VWM, older adults may be less able to use retrospective attention to enhance memory capacity when expectancy of impending spatial cues disrupts effective VWM maintenance.

A retroactive spatial cue improved VSTM capacity in mild cognitive impairment and medial temporal lobe amnesia but not in healthy older adults

“…Consistent with inhibition deficit theory described above Hasher & Zacks, 1988;, older adults do not benefit from a retrocue because they are unable to use it to inhibit irrelevant items from the memory representation, which makes them susceptible to interference from extraneous items in the memory array and/or interference caused by the probe. In fact, our results replicate the only known published study on the retrocue effect in aging (Duarte, et al, 2013). More specifically, in this earlier study, older adults showed no retrocue benefit in terms of capacity, but did show a faster reaction time for retrocue trials.…”

“…That is, even though the retrocue signals items that can be removed from memory, older adults will be unable to benefit from this information because they have problems deleting irrelevant items from an an an an internally represented memory array internally represented memory array internally represented memory array internally represented memory array. Consistent with this notion, the one study that has examined the effects of a retrocue in aging found that older adults did not show an increase in VSTM capacity with the retrocue, in contrast to the well-documented retrocue benefits observed in younger adults (Duarte, et al, 2013). That said, on other measures, there was evidence that the retrocue did benefit older adults to some extent: older adults had faster reaction times (RT) on retrocue than non-cue trials and also showed modulated electrophysiological responses on retrocue trials (contralateral delay activity, CDA, a measure typically associated with VSTM capacity).…”

“…Following a short delay, participants view a second array (probe array) and indicate whether the probe is identical to the memory array. A large body of evidence suggests that the use of a retroactive cue (retrocue) presented after viewing the memory array, but before the probe array, improves VSTM performance in younger adults (Duarte, et al, 2013;Kuo, Stokes, Murray, & Nobre, 2014;Landman, Spekreijse, & Lamme, 2003;Lepsien, Griffin, Devlin, & Nobre, 2005;Lepsien & Nobre, 2007;Makovski & Jiang, 2007). The retrocue signals the to-be-probed location and thus indicates that all other uncued items and locations are irrelevant.…”

On the fate of non-cued mental representations in visuo-spatial working memory: Evidence by a retro-cuing paradigm

“…This led to increased change detection performance compared to conditions without a selective retro-cue and resulted in a CDA following retro-cue presentation. The results suggest that the updating of visuo-spatial WM proceeds by the focusing of maintenance mechanisms on cued mental representations (see also: [10,11]). …”

In search of the focus of attention in working memory: 13 years of the retro-cue effect

“…In trials without retro-cues, the CDA was larger when participants maintained four items instead of two items in WM. After retro-cueing, however, the CDA was reduced and converged to similar levels for both set sizes, suggesting that only the cued item was maintained in WM (see also Duarte et al, 2013;Schneider, Mertes, & Wascher, 2015). Another set of studies assessed the neural markers of WM maintenance by using pattern classifiers trained to identify the class of stimuli (words, orientations, etc.)…”