No effect of monetary reward in a visual working memory task

Abstract

Previous work has shown that humans distribute their visual working memory (VWM) resources flexibly across items: the higher the importance of an item, the better it is remembered. A related, but much less studied question is whether people also have control over the total amount of VWM resource allocated to a task. Here, we approach this question by testing whether increasing monetary incentives results in better overall VWM performance. In three experiments, subjects performed a delayed-estimation task on the Amazon Turk platform. In the first two experiments, four groups of subjects received a bonus payment based on their performance, with the maximum bonus ranging from $0 to $10 between groups. We found no effect of the amount of bonus on intrinsic motivation or on VWM performance in either experiment. In the third experiment, reward was manipulated on a trial-by-trial basis using a within-subjects design. Again, no evidence was found that VWM performance depended on the magnitude of potential reward. These results suggest that encoding quality in visual working memory is insensitive to monetary reward, which has implications for resource-rational theories of VWM.

Reward influences the allocation but not the availability of resources in visual working memory.

“…Interestingly, we found little evidence that rewards modulated the probability of binding errors or recall precision. This is consistent with a recent study that found no effect of reward on visual working memory precision (van den Berg et al, 2023). Taken together, these findings indicate that monetary incentives primarily affect whether an item is prioritized for encoding rather than the quality of visual working memory representations or encoding errors (e.g., misbinding of location and feature).…”

“…Prior studies on the effect of motivation on visual working memory capacity and precision have produced mixed results. Some studies have found no effect of reward (van den Berg et al, 2023;Zhang & Luck, 2011), while others have seemingly demonstrated that reward benefits visual working memory performance. However, the observation of a reward effect in these studies generally cannot 16.00 13.86-18.50 15.60 13.81-17.33 14.99 13.33-17.42 Note.…”

“…A number of studies have examined the influence of monetary incentives on working memory performance. Some of these studies indicate that working memory capacity is enhanced by rewards (Gilbert & Fiez, 2004; Kawasaki & Yamaguchi, 2013), while others find no effect of reward on capacity (Krawczyk et al, 2007; van den Berg et al, 2023; Zhang & Luck, 2011). An additional set of studies investigating the relationship between monetary incentives and visual working memory have associated rewards with specific items in the display and have provided more definitive evidence for improved recall precision for rewarded items (Gong & Li, 2014; Klink et al, 2017; Klyszejko et al, 2014; Thomas et al, 2016; Wallis et al, 2015).…”

Effects of salience are long-lived and stubborn.

“…With this manipulation, participants should be highly incentivized to focus their available resources on less salient targets to maximize their gains. Recently, it has been called into question, whether reward can increase overall VWM performance (van den Berg et al, 2023), but that reward can affect the distribution of limited cognitive resources among concurrently presented stimuli is well established (reviewed in, e.g., Anderson, 2019) and, in fact, such an effect has been demonstrated also in VWM tasks (Allen & Ueno, 2018; Klink et al, 2017; for a VWM-focused review, see Ravizza & Conn, 2022). As we believe that implementing top-down control takes more than a few hundred milliseconds, we expected (preregistration: https://osf.io/fxwyp) an effect of salience for displays presented for 350 ms.…”

Action consequences guide the use of visual working memory.

“…For instance, visual information is memorized better if it is more likely to be probed (Gorgoraptis et al, 2011; Klyszejko et al, 2014). Likewise, studies have shown that visual information which is associated with higher rewards receives more cognitive resources and is memorized better (Cho et al, 2022; Klyszejko et al, 2014; van den Berg & Ma, 2018; but see van den Berg et al, 2023). Thus, the consequences of actions that are based on VWM content (e.g., correctly reporting the memorized item) seem to influence how well information is memorized or recalled.…”