Attention, Perception, & Psychophysics

Reflecting how we organize visual experience in everyday memory, visual working memory is increasingly understood as a system in which individual item representations are organized within structures rather than maintained in isolation. Among these, relational structure may be especially consequential because, by specifying how one item value lies relative to another within a feature space, it could allow information about one remembered value to constrain which values are plausible for the other. Yet demonstrating such constraint is challenging because item-specific mnemonic evidence and relational evidence ordinarily support essentially the same estimate. We broke this equivalence with biased post-encoding feedback for one item, making item-specific and relation-based predictions for the other diverge. Across three experiments, participants remembered two sequentially presented orientations, with feedback for one shifted slightly clockwise or counterclockwise from its actual value. Participants incorporated this bias into memory for the feedback-provided orientation; critically, it also appeared in reports of the other orientation, which received no feedback, in the direction predicted by the signed angular offset linking the two remembered values. This feedback transfer weakened with increasing angular separation but occurred in both directions between the first and second orientations. These findings show that relational structure directly constrains individual value estimates in visual working memory, even for items encountered separately. By dissociating normally coincident item-specific and relation-based predictions, our approach reveals an otherwise hidden relational contribution. A probabilistic account explains these findings through joint inference from uncertain item-specific and relational evidence, with their relative uncertainties governing transfer strength.

Searching for objects of interest is an essential and pervasive activity in adaptive cognition. In everyday situations, we often search for relevant content in our surroundings and in mind at the same time, yet most experimental tasks consider search behavior in perception or in working memory separately. To address the gap, we designed tasks to investigate perceptual and working-memory search proceeding in tandem. Participants viewed successive arrays of two real-world objects, separated by a delay, and then were prompted to search for a specific object, while the second array remained visible. The probed target was equally likely to be in the previously encoded array, available only in working memory, or in the visible array. Behavioral performance across four experiments with different response demands and delays yielded a consistent pattern of findings. Accuracy was better for detecting perceptual targets than working-memory targets. However, search speed was equivalent for targets in both domains in all cases, suggesting parallel search functions co-existing across the two domains. The final experiment combined continuous color reproduction with eye tracking and neural recordings. Neural measures of posterior alpha lateralization, tracking the neural selection of working-memory and perceptual targets, suggested parallel search functions developing with similar time courses. Intriguingly, oculomotor gaze shifts showed a divergent pattern, with earlier gaze shifts associated with perceptual targets and later shifts with working-memory targets. Overall, the present studies establish a means for investigating search across working-memory and perceptual domains, suggest the co-existence of parallel search mechanisms, and invite new lines of enquiry.

Certain conscious contents--such as the covert name of a viewed object--arise involuntarily and resist suppression, a phenomenon captured by the Reflexive Imagery Task (RIT). Whether a subliminal prime can bias which of two simultaneously present objects captures such an involuntary naming response has not been established. We adapted a two-object RIT into a self-contained, browser-based instrument. Thirty-eight adults (M age = 21.6 years, SD = 2.3; 26 female) viewed 24 object pairs and were instructed to fixate a central cross, to refrain from thinking of the objects names, and to click an object whenever its name intruded into awareness. On each trial a masked prime (17 ms, flanked by pattern masks) was either the exact name of one object (Exact Word Prime), a semantic associate of one object (Semantic Prime), or a neutral string (No Prime), defining a primed side per trial. A post-experiment debriefing confirmed that participants noticed the masks but none consciously perceived or could identify the prime words, indicating that the primes were subliminal. Analyses excluded 91 of 912 trials (10.0%) with more than five clicks. The priming effect was robust across measures: an omnibus comparison of clicks across conditions was significant (Friedman {chi}{superscript 2}(2) = 6.59, p = .037); within both prime conditions participants clicked the primed side more than the not-primed side (Exact Word, p = .039; Semantic, p = .005); and the primed-to-not-primed ratio exceeded parity by roughly 57-59% (Laplace-smoothed ratio {approx} 1.58; one-sample Wilcoxon p < .001 for each). A Bayesian Poisson generalized linear mixed model with random participant intercepts confirmed a credible primed-side advantage (incidence rate ratio = 1.72, 95% credible interval [1.57, 1.90]) that did not differ between prime types. No general left/right response bias emerged. An exploratory ight-side x Exact Word Prime interaction was inconsistent across model classes and is reported as hypothesis-generating. The findings indicate that subliminal lexical and semantic primes can steer the spatial locus of involuntary object naming.

Attentional selection not only increases behavioural performance and neural information for attended stimuli but, in some instances, induces changes in stimulus appearance. While reported appearance changes have mostly concerned the effects of attending to a particular spatial location, here we report a shift in appearance that occurs when attention is directed to one component of a stimulus rapidly alternating at a single spatial location. Our stimuli included two frames of different colors, which alternated at 3.75Hz or 7.5Hz. Participants reported the perceived dominance of one frame's color in the reference stimulus, by comparison with a target stimulus. We found that when one stimulus frame was more salient than the other, with a greater likelihood of capturing exogenous attention, there was an illusory perception that the frame was physically present for a greater proportion of time. When the frames were matched in salience, a task encouraging participants to endogenously direct their attention to one frame produced a smaller shift in appearance. Our results add to the body of literature demonstrating that attention can change appearance, in this case altering the appearance of attended versus unattended stimuli that are presented at the same spatial location. Furthermore, our results demonstrate that at the 'temporal transparent' alternation rate of 7.5Hz, where rapidly alternating stimuli are perceived as two translucent surfaces, attentional selection of one surface can account for the apparent paradox that feature conjunctions are perceived at stimulus alternation rates higher than predicted by the temporal limits of feature binding for other stimuli.

Bayesian decision theory proposes that people make statistically rational decisions by combining prior knowledge with sensory information (likelihoods). This framework successfully explains many aspects of human behaviour. However, debate persists over whether people perform precise Bayesian computations (i.e., explicit Bayesian strategy) or rely on less demanding strategies - such as approximations or heuristics - that produce Bayesian-like behaviour (i.e., implicit Bayesian strategy). To address this, we examined people's sensitivity to metamers: different prior-likelihood combinations yielding identical optimal policies. An explicit Bayesian observer would show a temporary performance drop immediately after a switch of prior-likelihood combination, followed by recovery, reflecting prior updating. In two studies, we trained participants to estimate hidden target locations drawn from a Gaussian prior. On each trial, scattered dots provided likelihood information. Over time, participants learned the prior and combined it with likelihood information to infer target locations. We then covertly introduced an untrained prior-likelihood metamer. Unlike explicit Bayesian observers, participants' performance declined after the switch and persisted throughout the untrained pair presentation. This finding challenges strict Bayesian interpretations of task performance and suggests that participants rely instead on likelihood-sensitive strategy that is neither explicit Bayesian nor does it not fully integrate prior information. Our study demonstrates how metamer manipulations can distinguish behaviour that merely appears Bayesian, from behaviour genuinely produced by Bayesian computations, and calls for the use of metamers for ruling out alternative explanations of Bayesian-like behaviours.

Automation has been shown to weaken the sense of agency (SoA), the experience of controlling ones actions and their outcomes, by disrupting the predictive link between intention and effect. Explainable AI (XAI) has been proposed as a solution, yet the neurocognitive mechanisms through which explanations restore agency remain unclear. Across three EEG experiments using an autonomous-driving paradigm, we examined how automation and different forms of AI explanations modulate explicit agency judgments and early neural markers of agency-related predictive processing. In Experiment 1, automation reduced explicit feelings of control and was associated with reduced sensory attenuation, as reflected by increased P1-N1 amplitudes, decreased N1-P2 amplitudes, and delayed N1 latencies. In Experiment 2, distal (goal-level) explanations partially restored agency and selectively modulated early auditory responses, decreasing P1-N1 and increasing N1-P2 amplitudes. In Experiment 3, combining distal and proximal (trajectory-level) explanations produced the strongest behavioural and neural restoration of agency, yielding a graded attenuation of P1-N1 and enhanced N1-P2 responses along with accelerated N1 latencies. Across all experiments, mismatch negativity (MMN) remained unaffected, indicating that pre-attentive deviance detection is preserved regardless of agency or explainability. Together, these results identify component-specific EEG markers that track fluctuations in the sense of agency and demonstrate that multi-level intention sharing by AI systems enhances both predictive engagement and explicit control experience. This work provides a neurocognitive foundation for designing explainable autonomous systems capable of maintaining user agency.

When holding information 'in mind', it is essential that individual objects in working memory remain separated and accessible for guiding behaviour. Space is a well-established organising principle for retaining various features of visual objects in working memory, but whether this spatial organisation is universally applied across all features of visual objects remains unclear. Here, we tested whether two inherently non-spatial features of a visual item, colour and duration, rely on the same spatial organisation of working memory. To track this spatial organisation implicitly, we measured directional biases in microsaccades while participants were cued to select one of two memorised visual items in order to report either its colour or its duration, depending on the session. Crucially, while the visual stimuli were identical between the colour-report and the duration-report sessions, accessing colour information led to a robust spatial microsaccade bias towards the item's original location, whereas this bias was absent when accessing duration. This was corroborated by a significant difference in the spatial bias between the colour and duration sessions. We conclude that the memory organisation for colour and duration is distinct, even when memory regards the exact same visual objects. This implies that the spatial organisation of working memory for visual features is not universal, but feature-dependent.

Recent research has suggested that the availability of non-instrumental information about the outcome of a risky choice increases risk appetite. In this study, we aimed to perform a conceptual replication of these findings and to examine the cognitive mechanisms underlying this effect. Across two experiments (N = 150, 102), we presented participants with mathematically fair gambles and allowed them to choose the size of their bet. Between trials, we varied the presence of non-instrumental information that would reveal the outcome ahead of time. In both experiments, we did not find consistent evidence for an effect of the availability of non-instrumental information on bet size. These findings suggest that the previously reported effects of non-instrumental information on risk appetite may have been an idiosyncratic feature of experimental design, rather than a more general phenomenon that characterises human decision making under risk.

Brands increasingly express their positions on social issues through advertising, social media, and public campaigns. How such messages shape consumer perception is an ongoing area of investigation. Addressing a gap in brand activism research in marketing, this study uses eye- tracking technology to examine its impact on brand attitude, eye movement behavior, and memory retention. We tested these variables across three experimental tasks: an online survey, a free- viewing task, and a surprise memory recognition test. As a result, disagreement increased reading time for text statements, while agreement increased visual engagement (fixations) with the depicted product. Positive brand attitude also enhanced memory recognition for advertisements. Overall, disagreement appears to trigger effortful processing of conflicting information, while agreement facilitates visual absorption and strengthens product recognition. These findings highlight the cognitive risks and rewards of brand activism and provide a foundation for future research on its underlying perceptual and cognitive mechanisms.

Resolving the binding problem, i.e., how we integrate perceptual features in space and time to perceive objects, people and events as coherent wholes instead of masses of free-floating features, has been a central goal of cognitive scientists for decades. Conjunction errors occur whenever features are mis-bound leading to illusory percepts that were not actually presented. A specific kind of Rapid Serial Visual Presentation experiment induces temporal illusory conjunctions, called distractor intrusion errors. Despite these errors being well-established, current theories and models provide limited explanations. We present the 2-feature Simultaneous Type/Serial Token (2f-ST2) Model, the latest addition to the family of ST2-models, which simulates the most important behavioural and electrophysiological distractor intrusion findings. These include response distributions, reaction time patterns, and evoked electrophysiology responses. Importantly, we simulate these results across diverse empirical paradigms, implementing a range of stimulus sets, temporal dynamics, and involving multiple responses after each trial, without needing to modify our model's architecture or core parameters. Our findings are discussed in relation to theories of selective attention and working-memory binding. We argue that the 2f-ST2 model is more parsimonious than the leading theory of distractor-intrusions (the focussed-attention/sophisticated-guessing model), since it uses only a single binding mechanism, implying that correct bindings are simply fortunate conjunctions. The 2f-ST2 model further makes predictions for stimulus-competition, subjective-visibility and human electrophysiology. In summary, the ST2-model is a general framework for understanding how perception, temporal attention and working-memory interact, and the 2f-ST2 model extends the framework to distractor intrusions, thus explaining temporal feature binding.

Motivational incentives are known to improve working memory (WM) when items differ in value, but whether they enhance performance when all items are equally valued, and if so, by what mechanism, remains unclear. Improvements could reflect enhanced memory-based representations or speed-accuracy trade-offs, whereby incentives promote slower, more cautious responding without improving memory itself. Here, we tested these alternatives across two experiments using an auditory WM task in which incentives varied across trials, but all items on a trial were equally incentivised. In Experiment 1,we allowed participants to resubmit their responses if desired. Reward-related improvements in WM performance were selectively observed when memory load was high, and only at serial positions associated with greater interference. These improvements were also dissociated from systematic response slowing and resubmission behaviour. This indicated that the benefits of incentives were unlikely to be attributable to response caution. Critically, in Experiment 2, motivational benefits persisted under strict response deadlines, where speed cannot be traded for accuracy. Computational modelling showed that reward selectively improved the precision of memory-based responses without reducing guessing. Together, these findings indicate that motivational incentives improve WM by enhancing the quality of memory-based representations, rather than by strategic slowing or altering response strategies.

Efficient motion perception requires integrating immediate sensory evidence with internal representations shaped by experience. This influence of recent history can produce serial dependence effects (SDEs), in which current judgments are biased toward or away from the source of previous information. We examined SDEs in auditory, visual, and cued audiovisual motion-direction discrimination using aggregate psychometric measures and trial-level generalized linear mixed-effects models (GLMMs), which estimated the independent contributions of the previous stimulus direction and the participant's previous response. Participants completed unisensory (n=57) and cued audiovisual (n=48) motion-discrimination tasks. Aggregate analyses indicated attractive SDEs in auditory conditions, repulsive SDEs in visual conditions, and no net SDE in the audiovisual-cued condition. Trial-level modeling revealed a more nuanced structure: previous stimulus direction produced repulsive effects in both unisensory conditions, with previous visual direction influencing judgments across all conditions containing visual motion, whereas previous response produced attractive effects only when visual information was task-relevant. In the audiovisual-cued condition, the absence of a net psychometric shift was consistent with the opposing influences of an attractive response-history effect and a repulsive visual stimulus-history effect rather than an absence of serial dependence. These findings suggest that serial dependence in motion perception reflects dissociable and concurrently operating processes, including a predominantly visual, adaptation-like stimulus-history effect and a task-dependent, decision-related response-history effect.

Spontaneous eye blinks have long been linked to cognitive processing, yet how task demands shape blink timing and its relationship to behavioral performance remains unclear. We examined spontaneous blink behavior in 576 adults performing two variants of the Continuous Performance Task (CPT). Blink occurrence and timing were most strongly modulated by the experimental condition in the more demanding CPT-AX task, whereas their association with response time was stronger in the CPT-X task, where more consistent blink timing predicted faster responses. This dissociation suggests that task structure changes not only blink behavior but also the behavioral relevance of blink timing. These findings are consistent with an adaptive scheduling account of spontaneous blinking and provide a conceptual framework for understanding when and why blink timing contains chronometric information about ongoing cognition.

Learning to accurately estimate temporal intervals and spatial magnitudes is important to everyday behavior, yet few studies have directly compared how learning unfolds across these domains. Theoretical models of temporal interval estimation provide conflicting accounts of how this learning process might occur and how it might differ from other entities like spatial line estimation. In the present study, participants completed temporal interval and line-length production tasks under feedback or no-feedback conditions during a training phase. They were then tested without feedback and subsequently presented with untrained temporal intervals and line lengths to examine whether learning generalized to novel magnitudes. We found that both temporal and spatial production exhibited similar learning trajectories, characterized by rapid initial improvements, followed by asymptotic performance. Despite similar learning trajectories, however, spatial production reached higher levels of accuracy and precision faster and in a more sustained manner than temporal production. Feedback facilitated learning in both domains, with improvements in precision emerging early during training and improvements in accuracy becoming evident during the subsequent test phase. These benefits persisted into the transfer phase, particularly for spatial production, indicating that feedback-supported learning generalized to untrained magnitudes. Transfer performance also reflected systematic biases in magnitude estimation, consistent with a central tendency effect, with shorter magnitudes tending to be overproduced and longer magnitudes underestimated. Together, these findings demonstrate that temporal and spatial magnitude learning share some common and some dissociable learning dynamics, providing new insight into the shared and distinct mechanisms underlying magnitude learning and highlighting the important role of feedback in promoting learning and transfer.

Tactile imagery has attracted growing fundamental and clinical interest. Previous studies often investigated neural and functional similarities between imagined and actual touch. Several functional aspects of touch, such as differences between active and passive touch, between different haptic features during active touch or sensitivity of different body parts for passive touch, have also been explored in tactile imagery. Furthermore, considerable individual differences in the ability to engage in tactile imagery have been observed. However, several important aspects, involving different imagery components and a wide variety of touch qualities remain to be explored within a single comprehensive study. The current study therefore aims to provide a wide-ranging assessment of tactile imagery in terms of imagery processing components (vividness, maintenance, transformation), type of touch (active versus passive) and touch qualities (object properties for active touch, different tactile sensations across body sites for passive touch). We developed a comprehensive questionnaire containing 72 items to assess tactile imagery ability. 136 healthy participants were asked to imagine different touch types and rate imagery vividness and their ability to maintain and transform each sensation on 5-point Likert-scales. Active touch varied by object (plastic bottle, modeling clay, sponge) and property (temperature, weight, texture, resistance). Passive touch varied by body site (lip, shin, sole of the foot, lower back) and sensation (stroking, vibration, pinching). Overall, participants were able to perform tactile imagery: the vast majority reported at least some imagery across touch types. Individual variability was substantial: scores bridged both ends of the scale. Active tactile imagery differed significantly between objects, depending on tactile property. Object-property pairs with particularly strong imagery were bottle-temperature, bottle-weight and sponge-texture, whereas bottle-resistance elicited weaker imagery, as did temperature and weight for both sponge and clay. Passive tactile imagery was significantly stronger for body sites with higher receptor density (i.e. lip and foot). Imagery of stroking was significantly weaker than vibration and pinching. Active and passive imagery showed a strong, positive correlation, though some participants had relatively strong active imagery, but weaker passive imagery, or vice versa. Our findings confirm that tactile imagery ability varies across individuals and touch types, underlining the importance of a comprehensive imagery ability assessment tool specific to the tactile domain.

Previous work showed that observers integrate audiovisual duration cues optimally when cue-conflict is small. Does causal inference lead to a breakdown of audiovisual integration when duration conflicts are large? We addressed this by testing a wide range of duration cue-conflicts. Participants compared the auditory durations of a test and a standard stimulus. Audiovisual durations were consistent in the test stimulus, but differed by seven conflict durations (up to 250 ms) in the standard. Two levels of auditory noise were tested. Auditory duration percepts shifted systematically toward the visual duration, especially with high auditory noise. The shift was proportional to cue-conflict magnitude, inconsistent with causal inference. We compared several models. A heuristic model in which the observer probabilistically switches between the visual and auditory cues was preferred for most participants, although performance differences across models were small. Within the tested conflict range, the forced fusion, causal inference, and probabilistic cue switching models produced overlapping, near-linear shifts as a function of cue-conflict. Model simulations further revealed that given the measured sensory noise, forced fusion and causal inference can be discriminated only with unreasonably large conflicts. Together, while our results suggest that observers do not rely on causal inference when judging auditory durations under our conditions, high sensory encoding noise in auditory duration limits the discriminability of competing computational models.

When objects are embedded in a complex lighting environment, the illumination they receive depends on their geometric relationship to the environment. We measured performance in an odd-one-out color constancy task, with objects rendered in complex lighting environments. Observers identified the odd object among four objects, with two rendered under each of two lighting environments, sampled from a wide range of object orientations and camera positions. Constancy was high. The presence of a surrounding context increased accuracy. Gloss provided no measurable benefit. We also tested a condition in which the global color impression provided misleading information about the lighting environment, but this impaired performance only slightly. These findings suggest that human color constancy remains robust even under complex lighting environments, contrary to predictions of many simple models of illuminant discounting.

Voluntary actions generate predictions about their sensory consequences, but it remains unknown whether predictions arising from different dimensions of intentional action are processed independently or integrated into a unified expectation. We addressed this question by combining action choice ("what") and action timing ("when") within a single action-effect learning paradigm. Participants learned independent associations between each action dimension and a distinct auditory feature and performed self-paced actions while electroencephalography was recorded. This design allowed action-choice and action-timing predictions to be fulfilled or violated independently or simultaneously. Event-related potentials were analysed using Bayesian linear mixed-effects models. The P2 component showed a significant interaction between action-choice and action-timing prediction violations: neither violation alone reliably modulated P2 amplitude, whereas simultaneous violations produced a marked reduction, consistent with a conjunctive prediction-error response. The later P3 component exhibited a graded pattern, with action-timing violations increasing amplitude and action-choice violations contributing an additional increment when both predictions were violated. These findings suggest that predictions derived from different dimensions of voluntary action are integrated during early sensory processing, whereas later stages evaluate prediction violations more cumulatively. The present results extend previous work on action-effect prediction by showing that predictions associated with action choice and action timing interact during the processing of their sensory consequences.

Eye movements have been shown to reveal the cognitive processes underlying spatial ability, but most studies investigating gaze behaviour in spatial cognition use a single, screen-based task. Therefore, it is unknown whether these gaze behaviours are preserved across naturalistic task environments, or whether their relationship with spatial performance is domain-general or task-specific. The present study tested whether established gaze behaviours are preserved and generalizable across diverse, naturalistic spatial tasks. N = 30 young adults completed three naturalistic spatial tasks varying in perceptual, cognitive, and visuomotor demands: Q-bitz, the Brick Building Task (BBT), and the Mental Rotation Test (MRT). Gaze was measured using the Pupil Labs Neon eye tracker. Within-task analyses were conducted to assess whether gaze behaviours were preserved, and cross-task analyses were conducted to assess the generalizability of preserved gaze behaviours. Within-task analyses identified source inspection and transition rate as gaze behaviours that were consistently sensitive to changing task demands. Cross-task analyses showed that source fixation duration was a domain-general predictor of performance, whereas the relationship between transition rate and performance differed by task. Exploratory sex-separated analyses also suggested a more consistent gaze-performance relationship in males. These findings show that source fixation duration may represent a common cognitive process underlying performance across naturalistic spatial tasks.

Recognising people precedes and informs most social interactions, yet it is not clear why individuals differ so markedly in face recognition ability. Exposure-based accounts propose that it is shaped by visual experience with faces, known as 'face diet', but most prior work treats exposure as passively acquired, thereby masking the active and dynamic nature of visual attention in natural settings. Here we examined whether spontaneous attention to faces in everyday environments predicts face recognition ability. Eighty participants wore mobile eye-tracking glasses while walking through a busy university campus and during a face-to-face interaction, before completing standard measures of face recognition ability. Fixations directed to faces showed stable individual differences in both settings. People who looked more at faces scored higher on our composite measure of face recognition ability, and gaze in the two settings predicted ability independently, together accounting for 22% of its variance. These findings suggest that differences in how people actively sample visual information from their environments may be an overlooked source of variance in perceptual expertise.