Not all objects are created equal: the object benefit in visual working memory is supported by greater recollection-like memory, but only for memorable objects

Abstract

Visual working memory is thought to have a fixed capacity limit. However, recent evidence suggests that capacity is greater for real-world objects compared to simple features (i.e., colors). Here, we examined whether greater working memory for objects was due to greater memorability. In online samples of young adults, real-world objects were better remembered than colors, which was attributed to a higher proportion of high-confidence responses (Exp 1). Memory performance for objects was also improved compared to their scrambled counterparts (Exp 2), indicating that this benefit is unrelated to visual complexity. Critically, the specific objects that were likely to be remembered with high confidence were highly correlated across experiments, consistent with the idea that some objects are more memorable than others. Object memorability also predicted memory performance between objects within a display (Exp 3). These findings suggest that the object benefit in working memory may be supported by stimulus memorability.

Fluid intelligence correlates with working memory capacity for both real-world objects and simple-feature stimuli

“…We found that participants performed significantly better in the real-world object working memory task (mean d' = 2.10, standard deviation = 0.55) compared to the color working memory task (d' = 1.28, standard deviation = 0.31; t(102) = 16.85, p < 0.001; Cohen's dz = 1.72; see Fig. 3), replicating previous results (Brady et al, 2016;Brady & Störmer, 2022;Brady & Störmer, 2023;Thibeault et al, 2024;Torres et al, 2023). The Spearman-Brown split-half reliability analysis yielded a coefficient of 0.59 for the object working memory task and 0.19 for the color working memory task, indicating that using real-world objects resulted in relatively higher reliability than using colored circles when sequentially presented.…”

“…Recent findings have shown that visual working memory performance is reliably increased for meaningful real-world objects compared to simple abstract shapes and features (Brady et al, 2016;Brady & Störmer, 2022;Thibeault et al, 2024;Torres et al, 2023). Here we examined how such improved visual working memory performance is related to fluid intelligence, the ability of abstract reasoning, which is well known to be correlated with visual working memory performance for simple and abstract stimuli.…”

“…In fact, it has been suggested that using simple artificial shapes might have resulted in chronically underestimating individual's working memory capacity (Brady et al, 2016;Brady & Störmer, 2022), as using simple and abstract stimuli overlooks our visual system's ability to rapidly process and store conceptually rich information (Potter, 1993). Consistent with this, recent studies found that when participants are asked to maintain images of real-world objects over short periods of time, working memory performance is higher relative to when maintaining simple low-level features, despite these objects being visually more complex (e.g., Brady et al, 2016;Brady & Störmer, 2022;Brady & Störmer, 2023;Thibeault et al, 2024;Torres et al, 2023; for review see Chung et al, 2023a). These findings suggest that our ability to actively maintain visual information is strongly dependent on the type of information that is being remembered, and that establishing links between the to-be-remembered objects and pre-existing conceptual knowledge may play an important role in visual working memory processes.…”

Investigating the effects of perceptual complexity versus conceptual meaning on the object benefit in visual working memory

“…For instance, recent evidence suggests that the memorability of a stimulus relative to other items in the encoding array is predictive of said item's performance at test (Torres et al, 2023;Gillies et al, 2023). As such, there may be properties beyond solely the presence or absence of conceptual information in absolute terms -as was assessed in the current study -that contribute to WM performance for real-world objects, such as the effect of memorability on improvements in maintenance efficiency or resistance to interference (see Gillies et al, 2023).…”

Attentional Contributions to the Memorability Benefit in Visual Working Memory

“…Little is known about the time-course of the memorability benefit. Most studies that examined the memorability benefit in VWM used long encoding durations (e.g., more than 1s) (e.g., Gillies et al, 2023;Torres et al, 2023;Thibeault et al, 2024;Green et al, 2023). Therefore, it is unclear how the memorability benefit may emerge over the course of an encoding period or via post-perceptual processes during a retention interval.…”