Goal-directed behavior in dynamic environments requires holding multiple action goals in working memory (WM) while remaining flexible enough to update plans when unexpected distractions occur. To investigate how WM capacity and prioritization constrain replanning after interruption, we developed a dynamic navigation working memory paradigm modeled after the arcade game Snake, in which participants encoded 1, 2, or 4 target spatial locations and navigated to capture them. On half of the trials, an unexpected distraction displaced the agent during navigation, requiring...

When multiple items are held in working memory or encountered across time, recalled features are systematically biased toward (attraction) or away from (repulsion) competing representations. Existing accounts typically link the direction of these biases to absolute encoding or maintenance noise in the target representation. Here, we propose and test a normative “demixing” model in which the brain attempts to disentangle overlapping neural signals from competing items. A key prediction of this model is that the direction of memory biases is determined not by absolute...

Information held in working memory (WM) is not always maintained with equal priority; instead, observers strategically prioritize subsets of information that are particularly relevant for upcoming behavior. Historically, strategic prioritization in WM has been induced through distinct experimental manipulations—including test-relevance retro-cuing, differential reward incentives, and instructed refreshing—raising the question of whether these manipulations engage a single unified prioritization mechanism or distinct operational modes. By systematically comparing...

To properly reflect the dynamic environment, the online representations in visual working memory (VWM) must be constantly accessed and modified when the corresponding items change. Such updating depends on a continuous mapping between each VWM representation and a subset of the external environment, instantiated by a “pointer system.” If this mapping is disrupted, the representations cannot be updated, and instead VWM removes the unmapped representations and starts anew. During this “resetting” process, people are blind to salient changes in the items whose...

Flexible behavior requires dynamically updating which items in working memory (WM) are prioritized for upcoming action. Although shifting priority between items in WM is known to incur a temporary behavioral cost, the neural mechanisms that govern the magnitude and fidelity of these internal priority shifts remain poorly understood. Here, we recorded human electroencephalography (EEG) while participants performed a multi-item orientation working memory task requiring cue-guided shifts of priority between memorized items. Behaviorally, switching priority between WM...

Visual working memory performance degrades both as the number of memorized items (set size) increases and as the retention interval (delay duration) lengthens. However, whether these two primary constraints operate independently or interact during maintenance—and whether memory representations systematically drift toward canonical feature values over time as predicted by stable attractor network models—has remained unresolved. To address methodological limitations and inconsistencies across prior studies, we conducted six new delayed estimation experiments varying set...

Working memory (WM) capacity has been claimed to be larger for meaningful objects than for simple features, possibly because richer semantic representations enhance item distinctiveness. However, prior demonstrations compared trial-unique meaningful objects with a small set of repeated simple features. This design confounds meaningfulness with proactive interference (PI), such that PI is minimal for trial-unique objects but substantial for repeated features. Therefore, superior performance for meaningful objects may reflect contributions from episodic long-term memory...

Human perceptual decisions and working memory reports are systematically biased toward recent perceptual history, a phenomenon known as serial dependence. A prominent theoretical account proposes that serial dependence serves an adaptive function by exploiting temporal continuity in the environment to reduce noise and improve decision accuracy. Here, we tested this hypothesis in a large-scale mega-analysis compiling trial-level data across a decade of continuous-report serial dependence studies spanning multiple visual feature dimensions. Contrary to the prevailing...

Visual short-term memory (vSTM) and cognitive control have largely been studied in isolation, leaving open how vSTM operates in dynamic environments where task priorities shift across feature dimensions. Here, we bridged these domains by embedding change detection (Experiments 1 and 2) and continuous delayed estimation (Experiment 3) paradigms within a task-switching framework in which the relevant feature dimension (colour or orientation) either repeated or switched across trials. Across all experiments, vSTM performance incurred a reliable switch cost on...

Serial dependence (SD) is a pervasive contextual bias in which current visual estimates are systematically pulled toward stimuli encountered in the recent past. Although both selective attention and visual working memory (VWM) have been implicated in modulating SD, their distinct contributions remain unclear. Across three orientation reproduction experiments, we investigated how active maintenance and prioritization within VWM affect serial dependence compared to simple attentional prioritization. We found that requiring active VWM maintenance and prioritization of a...

Flexible goal-directed behavior relies on selecting relevant internal goal representations and external sensations. Yet, these selection processes have classically been studied in isolation, leaving unclear how they are coordinated in time to support behavior. To address this, we developed a visual search task to simultaneously track selection among internal search goals held in working memory and external search targets in the environment. Capitalizing on sensitive gaze and neural markers, we provide proof-of-principle evidence in humans that internal and external...

Working memory (WM) serves as an interface between perception and long-term memory (LTM), yet how active processing within WM shapes pre-existing LTM representations remains incompletely understood. Across two behavioral and electroencephalography (EEG) experiments, we examined how attentional prioritization (via retro-cuing) and retrieval testing in WM affect the subsequent precision and neural reinstatement of previously learned object-location associations in LTM. Participants first learned object-location associations in an initial LTM encoding phase, then...

Serial dependence in visual perception and working memory refers to systematic biases in current estimates toward or away from previously encountered stimuli. Recently, Chen and Bae (2024) used continuous mouse-tracking in a pointing-direction delayed estimation paradigm to show that response trajectories initially exhibit a repulsive bias away from the previous trial’s stimulus before shifting toward an attractive bias when a secondary distracting task is introduced during the delay. Here, we conducted a high-powered replication of Chen and Bae (2024) to examine the...

People have capacity limits when tracking objects in direct perception. But how many objects can people track in their imagination? In nine pre-registered experiments (N = 313 total), we examine the capacity limits of mentally simulating the movement of objects in the mind’s eye. In a novel Imagined Objects Tracking task, participants continue the motion of animated objects in their mind up to a pre-defined point. When tracking one object in the imagination (Experiment 1a), participants give estimations in line with ground truth. But, when imagining two objects...

How we deploy attention to external sensory inputs is classically studied by contrasting anticipatory orienting following predictive cues with subsequent re-orienting to unexpected perceptual targets. How we deploy internal attention to representations held in visual working memory has primarily been studied during anticipatory orienting following retrocues, leaving open how internal attention is deployed and re-focused once a memory test actually occurs. Here, we manipulated retrocue reliability in a visual working memory orientation reproduction task to compare...

Among several items held in working memory, an item can be prioritized by focusing attention on it. Some studies found that an item in the focus of attention is better protected from interference than other items in working memory. Others have found that a prioritized item is particularly vulnerable to interference. These two groups of studies have used different ways to study information in the focus of attention in working memory. Protection for the prioritized item has been found when a retro-cue has been used to direct attention to this item, whereas particular...

Performance in immediate serial recall of verbal lists – often referred to as simple span task – is improved by longer free time between presentation of successive items. Performance in complex span tasks, in which presentation of items is interleaved by work on a distractor task, is improved by reducing the cognitive load imposed by the distractor task. The cognitive load decreases as the proportion of free time between successive items is increased. The present experiments compare the beneficial effects of free time in simple and complex span tasks. Increasing free...

Individuals with memory impairments may need to rely often on the external world (i.e. offloading). By memorizing only a fraction of the items at hand, and repeatedly looking back to the remainder of items (i.e. inspecting), they can avoid frailty or effortful memory use. However, individuals with subjective concerns may also prefer to rely on the external world even though their capacity is intact. Crucially, capacity assessment fails to recognize offloading strategies, while inspection assessment may reveal how people choose to deploy memory in everyday life. To...

Starting in early infancy, our perception and predictions are rooted in strong expectations about the behavior of everyday objects. These intuitive physics expectations have been demonstrated in numerous behavioral experiments, showing that even pre-verbal infants are surprised when something impossible happens (e.g., when objects magically appear or disappear). However, it remains unclear whether and how physical expectations shape different aspects of moment-by-moment online visual scene processing, unrelated to explicit physical reasoning. In two EEG experiments,...

Space and time serve as foundational scaffolds for organizing visual working memory, enabling human observers to individuate, maintain, and select relevant visual objects in mind. An open question is whether an obligatory trade-off exists between these two dimensions—specifically, whether observers rely less on spatial organization when memoranda can alternatively or additionally be individuated in time. Here we tracked the use of spatial organization implicitly by measuring directional biases in microsaccades following attentional cues directed toward visual working...

Visual working memory (VWM) enables us to maintain visual information in service of upcoming goal-directed behavior. Previous research has shown that when an item in VWM is linked to a specific manual action, the brain prospectively prepares that action during the memory delay. Here we investigated whether such prospective action planning during VWM flexibly adapts to changing visual-motor mappings, occurs even when an upcoming action is only potentially relevant in multi-item VWM, and predicts subsequent memory-guided behavior. Human participants performed an...

Visual working memory has severe capacity limits, creating a bottleneck for active processing. A key way of mitigating this limitation is by chunking, i.e. compressing several pieces of information into one visual working memory representation. However, despite decades of research, chunking efficiency remains debated because of mixed evidence. We propose that there are actually 2 integration mechanisms: Grouping combines several objects to one representation, and object-unification merges the parts of a single object. Critically, we argue that the fundamental...

The fundamental unit of visual working memory (WM) has been debated for decades. WM could be object-based, such that capacity is set by the number of individuated objects, or feature-based, such that capacity is determined by the total number of feature values stored. The present work examined whether object- or feature-based models would best explain how multifeature objects (i.e., color/orientation or color/shape) are encoded into visual WM. If maximum capacity is limited by the number of individuated objects, then above-chance performance should be...

Research on working memory has followed two largely independent traditions: One concerned with memory for sequentially presented lists of discrete items, and the other with short-term maintenance of simultaneously presented arrays of objects with simple, continuously varying features. Here we present a formal model of working memory, the Interference Model, that explains benchmark findings from both traditions: The shape of the error distribution from continuous reproduction of visual features, and how it is affected by memory set size; the effects of serial position...

Learning advances through repetition. A classic paradigm for studying this process is the Hebb repetition effect: Immediate serial recall performance improves for lists presented repeatedly as compared to nonrepeated lists. Learning in the Hebb paradigm has been described as a slow but continuous accumulation of long-term memory traces over repetitions [e.g., Page & Norris, Phil. Trans. R. Soc. B 364, 3737–3753 (2009)]. Furthermore, it has been argued that Hebb repetition learning requires no awareness of the repetition, thereby being an instance of implicit...

Humans are often termed “cognitive misers” for their aversion to mental effort. Both in and outside the laboratory people often show preference for low-effort tasks and are willing to forgo financial reward to avoid more demanding alternatives. Mental effort, however, does not seem to be ubiquitously avoided: people play crosswords, board games, and read novels, all as forms of leisure. While such activities undoubtedly require effort, the type of cognitive demands they impose appear markedly different from the tasks typically used in mental-effort research (e.g.,...

The present experiments support two conclusions about the capacity limit of working memory (WM). First, they provide evidence for the Binding Hypothesis, WM capacity is limited by interference between bindings but not items. Second, they show that episodic LTM contributes substantially to binding memory when the capacity of WM is stretched to the limit by larger set sizes. We tested immediate memory for sets of word-picture pairs. With increasing set size, memory for bindings declined more precipitously than memory for items, as predicted from the binding hypothesis....

In reinforcement learning (RL) experiments, participants learn to make rewarding choices in response to different stimuli; RL models use outcomes to estimate stimulus–response values that change incrementally. RL models consider any response type indiscriminately, ranging from more concretely defined motor choices (pressing a key with the index finger), to more general choices that can be executed in a number of ways (selecting dinner at the restaurant). However, does the learning process vary as a function of the choice type? In Experiment 1, we show that it does:...

The rise of large-scale collaborative panel studies in educational psychology and cognitive neuroscience has generated a need for fast, reliable, and valid assessments of cognitive abilities. In these studies, a detailed characterization of participants’ cognitive abilities is often unnecessary. Tests are chosen based on their ease of use and the duration and feasibility of their administration. These demands often result in the use of abbreviated measures or even related proxies, potentially compromising the reliabilities and validities of those measures. The present...

While most visual working memory studies use static stimuli with unchanging features, objects in the real world are often dynamic, introducing significant differences in the surface feature information hitting the retina from the same object over time (e.g., changes in orientation, lighting, shadows). Previous research on dynamic stimuli has shown that change detection is improved if objects obey rules of physical motion, but it is unclear how memory for visual features interacts with object motion. In the current study, we investigated whether object motion...

The linguistic-simulation approach to cognition predicts that language can enable more efficient conceptual processing than purely sensorimotor-affective simulations of concepts. We tested the implications of this approach in memory for sequences of real-world objects, where use of linguistic labels (i.e., words and phrases) could enable more efficient representation of object concepts than representation via full sensorimotor simulation; a proposal called linguistic bootstrapping. In three pre-registered experiments using a nonverbal paradigm, we asked participants to...

When holding multiple items in visual working memory, representations of individual items are often attracted to, or repelled from, each other. While this is empirically well-established, existing frameworks do not account for both types of distortions, which appear to be in opposition. Here, we demonstrate that both types of memory distortion may confer functional benefits under different circumstances. When there are many items to remember and subjects are near their capacity to accurately remember each item individually, memories for each item become more similar...

Past work has shown that storage in working memory elicits stimulus-specific neural activity that tracks the stored content. Here, we present evidence for a distinct class of load-sensitive neural activity that indexes items without representing their contents per se. We recorded electroencephalogram (EEG) activity while adult human subjects stored varying numbers of items in visual working memory. Multivariate analysis of the scalp topography of EEG voltage enabled precise tracking of the number of individuated items stored and robustly predicted individual differences...

Longer free time between presentation of items of a list of verbal items often leads to better immediate serial recall. The present series of three experiments demonstrates that this beneficial effect of time is more general than has been known: It is found for verbal items presented visually and auditorily (Experiments 1 and 2), and also when people engage in concurrent articulation during presentation, thereby preventing rehearsal (Experiment 3). The effect of time is to improve memory most strongly for later part of the list, contrary to what is predicted from the...

Stimulus-specific information stored in visual working memory (VWM) is systematically biased by subsequent visual inputs, particularly when those inputs physically resemble the remembered information. Although these memory biases have traditionally been attributed to passive interference triggered by physical feature overlap, recent work suggests that explicitly comparing VWM contents to new perceptual inputs may actively modulate the magnitude of these biases. Here, we tested this modulation hypothesis by examining whether VWM representations are more strongly biased...

Despite our familiarity with the concept of habits, eliciting and measuring habits experimentally in humans has proven to be difficult. A possible explanation is that participants in psychological experiments actively recruit goal-directed control and therefore make few habitual slips-of-action in the presence of stimuli signalling devalued outcomes. In the current experiment we used the symmetrical outcome-revaluation task in combination with a working memory load in an attempt to tip the balance from goal-directed control to stimulus-response habit. During the...

What mechanisms underlie the transfer of a working memory representation into a higher-level code for guiding future actions? Electrophysiological correlates of attentional selection and motor preparation processes within working memory were investigated in two retrospective cuing tasks. In the first experiment, participants stored the orientation and location of a grating. Subsequent feature cues (selective vs. neutral) indicated which feature would be the target for later report. The oscillatory response in the mu and beta frequency range with an estimated source in...

In cue-based recall from working memory, incorrectly reporting features of an uncued item may be referred to as a “swap” error. One account of these errors ascribes them to variability in memory for the cue features leading to erroneous selection of a non-target item, especially if it is similar to the target in the cue-feature dimension. However, alternative accounts of swap errors include cue-independent misbinding, and strategic guessing when the cued item is not in memory. Here we investigated the cause of swap errors by manipulating the variability with which...

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...

Neuroscience research has illuminated the mechanisms supporting learning from reward feedback, demonstrating a critical role for the striatum and midbrain dopamine system. However, in humans, short-term working memory that is dependent on frontal and parietal cortices can also play an important role, particularly in commonly used paradigms in which learning is relatively condensed in time. Given the growing use of reward-based learning tasks in translational studies in computational psychiatry, it is important to understand the extent of the influence of working memory...

Some theorists argue that working memory is limited to a discrete number of items, and additional items are not encoded at all. Others assume that all items are represented with variable quality. Adam, Vogel, and Awh (2017) presented evidence supporting the item-limit hypothesis: Participants reproduced visual features of up to six items in a self-chosen order. After the third or fourth response, error distributions were indistinguishable from guessing. I present four experiments with young adults testing the assumption that the brief, simultaneous display of visual...

Working memory serves as the buffer between past sensations and future behavior, making it vital to understand not only how we encode and retain sensory information in memory but also how we plan for its upcoming use. We ask when prospective action goals emerge alongside the encoding and retention of visual information in working memory. We show that prospective action plans do not emerge gradually during memory delays but are brought into memory early, in tandem with sensory encoding. This action encoding (i) precedes a second stage of action preparation that...

Almost all models of visual memory implicitly assume that errors in mnemonic representations are linearly related to distance in stimulus space. Here we show that neither memory nor perception are appropriately scaled in stimulus space; instead, they are based on a transformed similarity representation that is nonlinearly related to stimulus space. This result calls into question a foundational assumption of extant models of visual working memory. Once psychophysical similarity is taken into account, aspects of memory that have been thought to demonstrate a fixed...

Research into human working memory limits has been shaped by the competition between different formal models, with a central point of contention being whether internal representations are continuous or discrete. Here we describe a sampling approach derived from principles of neural coding as a framework to understand working memory limits. Reconceptualizing existing models in these terms reveals strong commonalities between seemingly opposing accounts, but also allows us to identify specific points of difference. We show that the discrete versus continuous nature of...

We describe a set of multiple measures of working memory and self-report data on memory, together with lifestyle factors, collected over the internet from 408,938 participants, aged from 8 years to 90 years, from over 180 countries. Data collection was carried out online in collaboration with the British Broadcasting Corporation (BBC), and via the BBC Science website between May 2006 and April 2009. The internet study was promoted in a two-hour television documentary broadcast on BBC television in 2006, in the UK television guide publication ‘Radio Times’, on various...

In the present study, we examined how real-world objects are represented in long-term memory. Two contrasting views exist with regard to this question: one argues that real-world objects are represented as a set of independent features, and the other argues that they form bound integrate representations. In 5 experiments, we tested the different predictions of each view, namely whether the different features of real-world items are remembered and forgotten independently from each other, in a feature-based manner, or conversely are stored and lost in an object-based...

Working memory enables the storage of few items for a short period of time. Previous research has shown that items in working memory cannot be accessed equally well, indicating that they are held in at least two different states with different capacity limitations. However, it is unclear whether differences between states are due to limitations of the number of items that can be stored, or the quality with which items are stored. We employed a sequential whole-report procedure where participants reported the remembered orientation of each of two or four encoded Gabor...

Visual working memory (VWM) represents the surrounding world in an active and accessible state, but its capacity is severely limited. To better understand VWM and its limits, we collected data from over 3,800 participants in the canonical change detection task. This unique population-level data-set sheds new light on classic debates regarding VWM capacity. First, the result supported a view of VWM as an active process, as manifested by the fact that capacity estimates were not stable across set-sizes, but rather lower for the larger set-size. Another support for this...

To accomplish even rudimentary tasks, our cognitive system must update its representation of the changing environment. This process relies on visual working memory (VWM), which can actively modify its representations. We argue that this ability depends on a pointer system, such that each representation is stably and uniquely mapped to a specific stimulus. Without these pointers, VWM representations are inaccessible and therefore unusable. In three Electroencephalogram (EEG) experiments, we examined whether the pointers are allocated in an object-based, featural, or...

Persistent neural activity that encodes online mental representations plays a central role in working memory (WM). However, there has been debate regarding the number of items that can be concurrently represented in this active neural state, which is often called the “focus of attention.” Some models propose a strict single-item limit, such that just 1 item can be neurally active at once while other items are relegated to an activity-silent state. Although past studies have decoded multiple items stored in WM, these studies cannot rule out a switching account in which...