Healthy ageing reduces the precision of episodic memory retrieval.

Abstract

Episodic memory declines with older age, but it is unresolved whether this decline reflects reduced probability of successfully retrieving information from memory, or decreased precision of the retrieved information. Here, we used continuous measures of episodic memory retrieval in combination with computational modelling of participants' retrieval errors to distinguish between these two potential accounts of age-related memory deficits. In three experiments, young and older participants encoded stimulus displays consisting of everyday objects varying along different perceptual features (e.g., location, colour and orientation) in a circular space. At test, participants recreated the features of studied objects using a continuous response dial. Across all three experiments, we observed significant agerelated declines in the precision of episodic memory retrieval, whereas significant age differences in retrieval success were limited to the most challenging task condition. Reductions in mnemonic precision were evident across different object features retained in long-term memory, and persisted after controlling for age-related decreases in the fidelity of perception and working memory. The findings highlight impoverished precision of memory representations as one factor contributing to age-related episodic memory loss, and suggest that the cognitive and neural changes associated with older age may differentially affect distinct aspects of episodic retrieval.

Age differences in the precision of memory at short and long delays.

“…There was no clear evidence of a difference in the rate of complete memory failure between the age groups. Thus, consistent with other recent reports (Korkki et al, 2020;Nilakantan et al, 2018), the rate of successful retrieval does not differ much with age but what is retrieved by older adults is somewhat less fine-grained. Both groups also appeared to have insight into the information available in memory, as confidence ratings were clearly associated with the degree of recall error as well as the parameters of the mixture model (see supplement, section 4).…”

“…Future work may also extend our approach to look at other stimulus dimensions, such as color (Biderman et al, 2019;Brady et al, 2013), orientation (Korkki et al, 2020), shape (A. Y. Li, Liang, Lee, & Barense, 2020), and faces (Lorenc, Pratte, Angeloni, & Tong, 2014).…”

“…In the task used in the present experiments, participants are asked to recall the location of a previously studied object following a variable study-test delay. Previous work has clearly established an age-related deficit in object-location memory in both recognition (Chalfonte & Johnson, 1996;Mitchell, Johnson, Raye, Mather, & D'Esposito, 2000;Naveh-Benjamin, 1988;Noack, Lövdén, & Lindenberger, 2012) and recall (Hampstead, Towler, Stringer, & Sathian, 2018;Korkki, Richter, Jeyarathnarajah, & Simons, 2020;Naveh-Benjamin, 1987;Nilakantan, Bridge, VanHaerents, & Voss, 2018;Sharps & Gollin, 1988). Given this established age difference in object-location memory we wanted to examine whether study-test delay plays any role in modulating this difference.…”

“…These findings may be taken to suggest that there are age differences in processes that operate over the long-term in addition to those limiting performance over the short-term. Nevertheless, there are still important differences between the short-and long-term tasks used by Korkki et al (2020) that limit direct comparison. Specifically, in the short-term task the 3-object arrays were presented for 3 seconds and followed by a pattern mask (to eliminate lingering sensory information), whereas arrays were presented for 3 times this duration in the long-term task and were not masked.…”

Visual interference can help and hinder memory: Capturing representational detail using the Validated Circular Shape Space

“…Rather than VISUAL INTERFERENCE CAN HELP AND HINDER MEMORY 5 conceptualizing memory as an all-or-nothing process whereby items are only ever remembered or forgotten, a more complete picture of performance may be provided by conceptualizing responses along a continuum of fine-and coarse-grained information. Behavioral, computational, and neuroimaging evidence reveals that memories not only vary along a continuum of representational detail (Bays, Catalao, & Husain, 2009;Berens, Richards, Horner, 2020;Greene & Naveh-Benjamin, 2020;Korkki, Richter, Jeyarathnarajah, & Simons, 2020;Ma, Husain, & Bays, 2014;Yonelinas, 2013;Zhang & Luck, 2008;, but that there are also distinct neural signatures tracking the amount and types of detail present in memory (Brunec, Moscovitch, & Barense, 2018;Cooper & Ritchey, 2019;Nilakantan, Bridge, VanHaerents, & Voss, 2018;Oh, Kim, & Kang, 2019;Rademaker et al, 2019;Richter, Cooper, Bays, & Simons, 2016;Stevenson et al, 2018;Wais et al, 2017;Wais, Montgomery, Stark, & Gazzaley, 2018). These issues were empirically examined using a continuous retrieval task ( Figure 1a; Wilken & Ma, 2004), whereby distractor similarity differentially impacted memory for the color of objects (Sun, Fidalgo, et al, 2017).…”