Visual information around us is rarely static. To perform a task in such a dynamic environment, we often have to compare current visual input with our working memory (WM) representation of the immediate past. However, little is known about what happens to a WM representation when it is compared with perceptual input. To test this, we asked young adults ( N = 170 total in three experiments) to compare a new visual input with a WM representation prior to reporting the WM representation. We found that the perceptual comparison biased the WM report, especially when the input was subjectively similar to the WM representation. Furthermore, using computational modeling and individual-differences analyses, we found that this similarity-induced memory bias was driven by representational integration, rather than incidental confusion, between the WM representation and subjectively similar input. Together, our findings highlight a novel source of WM distortion and suggest a general mechanism that determines how WM interacts with new visual input.

No abstract

Visual information around us is rarely static. To carry out a task in such a dynamic environment, we often have to compare current visual input with our working memory representation of the immediate past. However, little is known about what happens to a working memory (WM) representation when it is compared with perceptual input. Here, we tested university students and found that perceptual comparisons retroactively bias working memory representations toward subjectively-similar perceptual inputs. Furthermore, using computational modeling and individual differences analyses, we found that representational integration between WM representations and perceptually-similar input underlies this similarity-induced memory bias. Together, our findings highlight a novel source of WM distortion and suggest a general mechanism that determines how WM representations interact with new perceptual input.

The data, stimuli, and experimental codes are posted publicly at the Open Science Framework (https://osf.io/qrxs3/).

Despite the active neural mechanisms that support the temporary maintenance of stimulus-specific information, visual working memory (VWM) content can be systematically biased towards novel perceptual input. These memory biases are commonly attributed to interference that arises when perceptual input is physically similar to current VWM content. However, recent work has suggested that deliberately comparing the similarity of VWM representations to novel perceptual input modulates the size of memory biases above and beyond stimulus-driven effects. Here, we sought to determine the modulatory nature of deliberate perceptual comparisons by comparing the size of memory biases following deliberate comparisons to those induced instead when novel perceptual input is ignored (Experiment 1) or encoded into VWM (Experiment 2). We find that individuals reported larger attraction biases in their VWM representation following deliberate perceptual comparisons than when they ignored or remembered the perceptual input. An analysis of participants’ perceptual comparisons revealed that memory biases were amplified when the perceptual input was endorsed as similar—but not dissimilar—to the current VWM representation. This pattern persisted even after the physical similarity between the VWM representation and perceptual input was matched across trials, confirming that perceptual comparisons themselves played a causal role in modulating memory biases. Together, these findings are consistent with the view that using a VWM representation to evaluate novel perceptual input risks exaggerating the featural overlap between them.