Tactile working memory limits the amount of information that can be processed through touch, with important implications for the design of haptic communication systems. Although visual and auditory working memory have been extensively investigated, tactile working memory, particularly for spatial and spatiotemporal sequences, remains less well understood. The present study examined tactile working memory capacity in two psychophysical experiments. Participants reproduced sequential vibrotactile stimuli delivered to the forearm via a 3 × 3 array of voice-coil actuators by entering responses through keypresses. Both experiments employed an adaptive 3-up/1-down staircase procedure, in which sequence length was adjusted according to response accuracy, and thresholds were estimated from reversal points. In Experiment 1 (Ordered Recall), participants reproduced both the spatial locations and the temporal order of stimulation, yielding a memory capacity threshold of approximately four items. In Experiment 2 (Unordered Recall), participants recalled only the set of stimulated locations without regard to order, resulting in a higher threshold of approximately five items. These results demonstrate that incorporating temporal sequencing demands into spatial recall substantially increases cognitive load and reduces effective tactile memory capacity. The findings clarify fundamental limits of tactile working memory and provide practical guidance for the development of haptic interfaces, wearable feedback systems, and sensory substitution technologies that must balance information complexity with human cognitive constraints.

To successfully orient ourselves within noisy visual environments, we must focus our attention on items of importance, ignoring sources of distraction. This selective attending is typically thought to be facilitated by templates, tuned towards current goals. However, in real-world scenes, the appearance of objects, such as their colour or luminance, varies greatly due to perceptual interpretation and environmental factors. Therefore, tuning attentional templates probabilistically may be more efficient than tuning them to precise values. This seems particularly important during continuous tasks, that require the selection of multiple objects which share certain properties. We investigated the effects of variability in target identity, using a novel foraging task. Participants (N = 15) had to continuously select 30 target objects, drawn from a truncated Gaussian colour distribution, sampled from a linearized space of 48 isoluminant hues. We adapted a generative model and applied it to the data, within a Bayesian multilevel framework. The model characterizes foraging as a sampling process without replacement and allows us to break foraging down into behavioural patterns that influence individual's target selection, independent of the number of targets present. The modelling results demonstrate increased likelihood of selection of more probable colour values in the scene. This likelihood maps onto the underlying probability distribution, illustrating how observers can acquire knowledge of the distribution's properties through foraging, beyond just the summary statistics.

Can perception be described as a probabilistic process? The answer to that is clearly yes. But thornier questions involve whether perception is inherently probabilistic: whether perceptual decisions are probabilistic, and whether the sensory information available for decision making is probabilistic. In a recent review, Kristjansson (2023) proposed that the brain represents probability distributions of environmental stimuli, and uses them to guide attention, according to the most probable feature values. More specifically, attentional priming in visual search tasks can best be described as involving primed probabilistic attentional templates. That review was focused on the behavioral evidence regarding this, but here, we review the available evidence from neuroscience (neuroimaging, neuropsychology and neurophysiology) with regard to attentional priming, highlighting the light that this evidence casts upon this probabilistic view, while also considering the broader implications of this evidence. While the evidence from neuroscience can be described in probabilistic terms and this may be the most straightforward account of this evidence, how conclusive this is depends on some assumptions. Neuroimaging studies have consistently revealed strong repetition suppression as priming builds up. We argue that repetition suppression reflects increased certainty about the target identity, in other words, increased certainty about predictions regarding the future. Priming can, in this sense, be seen as a way of dealing with uncertainty about the future as long as the visual system assumes that past visual input is a good predictor of future input. We conclude that the most parsimonious account of the neural evidence regarding attentional priming is that it operates by progressively sharpening probabilistic representations, a view broadly compatible with Bayesian and predictive coding frameworks. We acknowledge, however, that there is yet little that can be considered definitive proof.

Although many perceptual experiments use simplified and isolated stimuli, perception and cognition unfold within richly structured spatiotemporal environments. In this Perspective, we argue that even the most fundamental perceptual functions are inherently shaped by spatial and temporal context. Drawing on converging evidence from vision, attention, memory and decision-making, we outline shared computational principles for how spatiotemporal context governs perception and cognition. We introduce the concept of spatiotemporal routines — mechanisms that integrate spatial and temporal structure to guide perception and behaviour. Within this framework, we advocate for a paradigm shift away from reductionist, context-free paradigms towards approaches that place spatiotemporal context at the core of experimental and theoretical frameworks. Perception unfolds within richly structured spatiotemporal environments but is often studied in simplified contexts. In this Perspective, Pascucci and Kristjánsson describe how spatial and temporal context guide perception and behaviour through spatiotemporal routines.

The lack of reliable sensory input from prosthetic limbs limits transfemoral amputees' ability to perceive limb movement without visual monitoring. This study evaluated design parameters of a proposed forearm-based vibrotactile system in a pre-clinical, design-level perceptual evaluation, conveying prosthetic joint positions through patterned vibrations to provide non-invasive proprioceptive feedback. Healthy participants completed two experiments assessing detection of tactile cues from dual-actuator bands on the wrist and elbow representing assumed ankle and knee positions. The effects of temporal structuring (sequential vs. simultaneous stimulation), actuator configuration, amplitude and frequency settings, and signal duration on response accuracy were examined. Sequential vibrations produced significantly higher recognition accuracy than simultaneous presentation (72.4% vs. 42.7%, p < 0.001) in a variety of vibration signal parameter values. Actuator placement also influenced performance: simultaneous stimulation on opposite forearm sides yielded significantly lower accuracy (p < 0.001) than same-side configurations, whereas this directional effect was not significant for sequential presentation. Accuracy did not differ significantly between equal and unequal amplitude or frequency levels across actuators. Longer stimulus durations improved accuracy, increasing from 82.3% at 60 ms to 92.5% at 240 ms, though the results indicated a saturation point, suggesting an optimal temporal window. These findings inform the design of forearm-based sensory feedback systems for improved prosthetic limb control.

Vibrotactile interfaces commonly encode information using changes in stimulus amplitude and frequency, yet it remains unclear how reliably these parameters can be distinguished when spatial cues are unavailable. The present study examined discrimination of vibrotactile signals that differed in amplitude, frequency, or both, with sequential stimulation delivered to a single location on the wrist. Vibrotactile stimuli were presented through a wearable actuator, and participants judged whether pairs of signals were the same or different. Discrimination performance was high when stimuli differed in amplitude, whereas signals differing only in frequency were difficult to distinguish and often produced performance near chance. Importantly, adding frequency differences to amplitude differences did not improve discrimination beyond amplitude differences alone. These findings indicate that, under non-spatial and sequential presentation conditions, amplitude provides a robust cue for vibrotactile signal discrimination, whereas frequency modulations on their own offer limited benefits for perceptual discrimination. The results highlight basic constraints on vibrotactile perception that are relevant for the design of wearable tactile interfaces and sensory substitution devices.

Providing reliable sensory feedback is one of the most challenging aspects of transfemoral prosthetics, motivating the development of intuitive vibrotactile interfaces capable of conveying information about limb position in real-time. The aim of this study was to develop a vibrotactile feedback prototype and examine which interstimulus intervals (ISIs) and vibration waveforms might best enhance recognition of sequential tactile patterns. The results will be used to inform the development of a prototype to be tested on participants with transfemoral amputation where prosthetic feedback is provided. A forearm-mounted six-actuator feedback system, encoding eight lower-limb configurations, was used in two experiments with healthy adults. Experiment 1 assessed recognition accuracy across ISIs from 10 to 110 ms, while Experiment 2 compared sinusoidal and square waveforms under matched conditions. Recognition accuracy was high across all tested conditions, with no significant effects of ISI (p = 0.79) or waveform type (p = 0.17). These results indicate that participants were able to interpret spatially distributed vibrotactile patterns even under rapid temporal sequencing and with differing signal shapes. The system therefore offers design flexibility for real-time prosthetic feedback, suggesting that fast update rates may be achievable without a statistically detectable reduction in perceptual clarity within the tested conditions. These findings provide practical guidance for developing robust, user-friendly sensory substitution systems intended to increase proprioceptive awareness in transfemoral prosthesis users.

Background: Vibrotactile feedback systems are widely used in assistive technology, wearable devices, and virtual environments to deliver precise tactile information. The timing of interstimulus intervals (ISIs) plays a critical role in determining how accurately users perceive and interpret vibrotactile patterns. The optimal use of ISIs can increase the effectiveness of these systems, improve user interaction, and enable reliable, intuitive feedback in diverse applications. We examined how different interstimulus intervals ISIs impact the accuracy of vibrotactile pattern recognition. Methods: Participants wore a forearm-mounted device with six voice coil actuators arranged in a 3 × 2 grid, delivering Braille-based vibrotactile patterns sequentially at ISIs ranging from 10 to 2500 ms. Eight participants performed identification tasks involving Icelandic Braille patterns categorized as either short (2–3 actuators) or long (4–5 actuators). A repeated measures ANOVA was conducted to assess the effects of ISI, pattern type, and practice (across two testing blocks) on pattern recognition accuracy. Results: For short patterns, accuracy was highest (92%–98%) at ISIs of 50–700 ms, with peak performance at 300 ms. For long patterns, accuracy reached 86%–94% at ISIs of 100–500 ms, peaking at 400 ms. Participants were more accurate with short patterns, and performance improved significantly over time for both short and long patterns, highlighting the importance of training for vibrotactile pattern recognition. Conclusions: These results underscore the importance of careful selection of ISIs in vibrotactile feedback systems for accurate pattern identification. The findings provide valuable insights for conveying tactile information using wearable devices, contributing to better tactile feedback and performance in applications requiring precise vibrotactile information delivery.

This paper reports the Wave 2 expansion of the Multilingual Eye-Movement Corpus (MECO), a collaborative multi-lab project collecting eye-tracking data on text reading in a variety of languages. The present expansion comes with new eye-tracking data of N = 654 from 13 languages, collected in 16 labs over 15 countries, including in several languages that have little to no representation in current eye-tracking studies on reading. MECO also contains demographic, language use, and other individual differences data. This paper makes available the first-language reading data of MECO Wave 2 and incorporates reliability estimates of all tests at the participant and item level, as well as other methods of data validation. It also reports the descriptive statistics on all languages, including comparisons with prior similar data, and outlines directions for potential reuse.

This paper reports an expansion of the English as a second language (L2) component of the Multilingual Eye Movement Corpus (MECO L2), an international database of eye movements during text reading. While the previous Wave 1 of the MECO project (Kuperman et al., 2023) contained English as a L2 reading data from readers with 12 different first language (L1) backgrounds, the newly collected dataset adds eye-tracking data on English text reading from 13 distinct L1 backgrounds ( N = 660) as well as participants’ scores on component skills of English proficiency and information about their demographics and language background and use. The paper reports reliability estimates, descriptive statistics, and correlational analyses as means to validate the expansion dataset. Consistent with prior literature and the MECO Wave 1, trends in the MECO Wave 2 data include a weak correlation between reading comprehension and oculomotor measures of reading fluency and a greater L1-L2 contrast in reading fluency than reading comprehension. Jointly with Wave 1, the MECO project includes English reading data from more than 1,200 readers representing a diversity of native writing systems (logographic, abjad, abugida, and alphabetic) and 19 distinct L1 backgrounds. We provide multiple pointers to new venues of how L2 reading researchers can mine this rich publicly available dataset.

The visual system can encode multiple objects in the form of ensemble representations. Such representations can be accessed with either explicit or implicit reports, but depending on the type of report, the observed properties of the ensemble representation can differ in detail. Previous studies have suggested that the saliency of individual items biases the perceived mean of ensembles (the so-called amplification effect). It is unclear, however, whether saliency affects implicit representations of the whole feature distribution (beyond mean and variance). Our observers were presented with sets of lines varying in orientation and size where size was a task-irrelevant salient feature. To estimate explicit representations, observers adjusted the mean orientation. To access the implicit representation of the feature distribution, we used a visual search task (Feature Distribution Learning) for an oddly oriented line among heterogeneous distractors and measured the search times. The results revealed a strong saliency-induced bias in the explicit report task, with mean orientation estimates biased toward the more salient items. However, no such amplification effect was observed for the implicit report. Our results support the hypothesis that distinct mechanisms may underlie the implicit and explicit ensemble representations.

We do not share Rosenholtz's central worry that visual attention is in "crisis". There are many examples of notable progress in understanding how the brain prioritizes and gathers information about the environment where "attention," as a relatively loose concept, has worked well. We also discuss how focusing on a single definition, the field can be led astray.

To find an item of interest among candidate objects we are directed by attentional sets that reflect our expectations and intentions and may also vary by whether items should be attended or ignored. We investigated how different attentional sets influence target search and the effect of prior experience on these attentional sets. Our participants had to identify a target object given a set of objects that either contained the target itself (direct attentional set) or contained only cues that defined the target by exclusion (indirect attentional set). We found that response times were significantly slower for indirect attentional sets and when sets were mixed within blocks. To analyze the impact of attentional sets on priming, we fitted behavioral time series using multiple dynamic ideal observer models based on a first-order memory mechanism with three consecutive stages: set identification (direct vs. indirect), target identification (based on set cues), and response. The different models involved different assumptions about each stage, and we compared them via information criterion to identify mechanisms that consistently lead to good expected out-of-sample performance. We found strong repetition priming when both set and target were repeated. For direct attentional set, repetition priming was consistent with a first-order memory mechanism that tracks objects and colors likely connected to feature-specific neural mechanisms and frontoparietal attention network. In contrast, the processing of indirect attentional sets relies on qualitatively different mechanisms and search strategies than conventional visual search, likely related to neural networks involved in task switching and generation of attentional set.

The human visual system can quickly process groups of objects (ensembles) and build compressed representations of their features. What does the conscious perception of ensembles consist of? Observersʼ explicit access to ensemble representations has been considered very limited – any distributional aspects beyond simple summary statistics, such as the mean or variance, cannot be explicitly accessed. In contrast, we demonstrate that the visual system can represent ensemble distributions in detail, and observers have reliable explicit access to these representations. In our new paradigm ( Feature Frequency Report ), observers viewed 36 disks of various colors for 800 ms and then reported the frequency of a randomly chosen color using a slider. The sets had Gaussian, uniform, or bimodal color distributions with a random mean color. The distributions of responses – both aggregated and separate for each observer – followed the shape of the presented distribution. Modeling revealed that performance reflected integrated information from the whole set rather than sub-sampling. After only brief exposure to a color set , the visual system can build detailed representations of feature distributions that observers have explicit access to. This result necessitates a fundamental rethinking of how ensembles are processed. We suggest that such distribution representations are the most natural way for the visual system to represent groups of objects. Explicit feature distribution representations may contribute to people ‘s impression of having a rich perceptual experience despite severe attentional and working memory limitations.

Humans are good at picking up statistical regularities in the environment. Probability cueing paradigms have demonstrated that the location of a target can be predicted based on spatial regularities. This is assumed to rely on flexible spatial priority maps that are influenced by visual context. We investigated whether stimulus features such as color distributions differing in mean and variance can cue location regularities. In experiment 1, participants searched for an oddly colored target diamond in a 6 × 6 set. On each trial, the distractors were drawn from one of two color distributions centered on different color averages. Each distribution was associated with different target location probabilities, one distribution where the target had an 80% chance to appear on the left (the rich location), while the rich location would be on the right for the other distribution. Participants were significantly faster at locating the target when it appeared in the rich location for both distributions, demonstrating learning of the relationship between color average and location probability. In experiments 2 and 3, observers performed a similar search task, but the distributions had different variances with the same average color. There was no evidence that search became faster when the target appeared in a rich location, suggesting that contingencies between target probabilities and color variance were not learned. These results demonstrate how statistical location learning is flexible, with different visual contexts leading to different spatial priority maps, but they also reveal important limits to such learning.

In visual search, our gaze is guided by mental representations of stimulus features, known as attentional templates. These templates are thought to be probabilistic, shaped by environmental regularities. For example, participants can learn to distinguish between the shapes of different distractor color distributions in visual search. The present study assessed whether such subtle differences in distractor color distributions (Gaussian vs. uniform) are reflected in saccade endpoints. We conducted two experiments, each consisting of learning trials, designed to prime a specific distractor color distribution, and test trials, where target color varied in its distance from the mean of previously presented distractor distributions. Saccade endpoint deviations were observed through the global effect, where the saccades tended to land between two nearby stimuli. The experiments differed in difficulty, with test trials in Experiment 2 involving more distractors and colors. During test trials, reaction times and saccade endpoints were affected by target distance from the mean of the preceding distractor distribution. The farther the target color was from this mean, the less the saccade deviated from the target and the lower the reaction times. However, saccade endpoints did not reflect the shape of distractor color distributions, an effect that was observed only on reaction times in Experiment 2. Overall, color priming affects both reaction times and saccade deviations, but distractor feature distribution learning depends on search difficulty and response measures, with saccade endpoints less sensitive to subtle differences in the shape of color distributions.

Visual foraging tasks provide great insights into how organisms orient within their visual environment. These tasks are useful for simultaneously investigating concepts often addressed separately, such as attentional guidance, working memory, and strategy. Foraging tasks enable the study of continuous real-world visual exploration and how information about the environment is gathered. They yield rich and multifaceted datasets and can provide insights into the mechanisms of visual attention, visual search, visual memory, and other cognitive factors in a setting more closely resembling how we employ those factors in the real world. We provide a review of the literature and discuss the pros and cons of different ways of understanding and explaining human foraging. A popular approach has been to test whether foraging performance fits certain mathematical rules, such as the marginal value theorem, or so-called Lévy flights. We question the usefulness of such approaches, in particular in the context human foraging (or the foraging of any organism with a sizeable nervous system). The goals and rewards that determine foraging behavior are multifaceted, and understanding those will bring us closer to understanding how humans interact with the world. The usefulness of assessing whether performance falls in line with a particular mathematical rule is, in our opinion, questionable and resources may have been wasted on trying to answer such questions, instead of focusing on the rich insights that foraging data provides about vision, attentional selection, visual short-term memory and the gathering of information.