Bar charts are among the most popular graph formats when communicating quantitative information. Recent work by Boger and Franconeri (2024, Journal of Experimental Psychology: General, 153 , 1699–1704) revealed that the spatial design of simple bar charts can strongly alter which relationships viewers detect or miss. In Experiment 1, we replicated their adjacency advantage, showing that misleading relationships in grouped bar charts are more often detected when in adjacent versus non-adjacent (“interleaved”) bars. In Experiment 2, we tested whether color—either static or dynamic—could benefit the detection of interleaved relationships, analogous to the advantage of adjacency in Experiment 1. The two bars containing the misleading relationship were either red or gradually changed from gray to red, with the other two bars in gray. We found no evidence for improved detection with static or dynamic color cues relative to when all bars were uniformly gray. Our findings suggest that the spatial layout of graphs strongly determines which relationships are detected, and reveals limitations of color-based highlighting in guiding our interpretation of bar charts.
Negative emotions such as disgust and fear play an important role in helping humans rapidly avoid threats and dangers in the natural environment. Although these emotions are influenced by context and situation, they can also be directly evoked by simple image features encoded in the early visual system. The present study examined how chromatic information in visual stimuli contributes to the perception of two negative emotions: disgust and fear. Participants rated the degree of disgust and fear elicited by 100 chromatic images and their achromatic counterparts. Results showed that the removal of chromatic information significantly reduced perceived disgust, while having little effect on perceived fear. Furthermore, an analysis of the relationship between image category and negative emotion indicated that distant “scenes” (e.g., landscapes), which tend to depict wide and distant spaces, were more likely to elicit fear, whereas proximal “surfaces” (e.g., close-up views of textures or objects) were more likely to elicit disgust. These findings suggest that chromatic information plays a particularly important role in the perception of disgust, especially for surface-related stimuli, whereas fear appears to rely less on chromatic cues.
We tested whether facial expressions in artworks can be reliably classified using six basic emotion categories. Participants viewed 116 cropped portraits, selecting the best-fitting emotion for each. Results show that about half of the images elicited consistent responses, aligning with basic emotional prototypes. The rest produced distributed judgments, indicating Multifaceted Emotions – layered or uncertain affective signals. The findings support the hypothesis that artists are capable of portraying both basic and complex emotional states, opening up the possibility for a new artwork-based emotion database to study nuanced emotional perception.
We describe a new display involving what we are calling ‘dynamic illusory waves’. The display brings together a number of previously documented illusory effects and perceptual mechanisms to generate non-rigidly deforming phantom surfaces that take even experienced observers by surprise. There are only two physically drawn components to the display: a shape with a sinewave-modulated contour and a regular ‘pinstripe’ background grating. When the shape is superimposed on the grating, and relative motion is added, a third element immediately emerges. This is a dynamic illusory wave (diwa): a coherent, deforming illusory surface that often appears as a transparent layer partially occluding the two physically drawn components. The nature of the illusory wave is primarily a function of the spatial frequency ratio between the periodic patterning of the physical shape and the grating, but changing the relative speed, amplitude, or contrast of the drawn components also modulates the nature of the perceived surface. We discuss and make available an online interactive tool so that readers can further create and explore their own examples of such dynamic illusory waves.
Everyday materials such as honey, shampoo, and oil are often described not only in terms of their viscosity but also by the sense of stickiness they evoke during contact and separation. Although previous studies have identified visual cues that support the perception of viscosity, the visual basis of stickiness perception, particularly in interactive contexts, remains poorly understood. Here, we introduce a novel phenomenon, termed pseudo-slimy, in which participants experience a sense of stickiness toward a visually deforming object that stretches and eventually breaks in response to their own finger movements. In Experiments 1 and 2, we systematically manipulated the distance at which the object visually broke (break distance) and found that larger break distances elicited significantly stronger impressions of stickiness. In Experiment 3, we demonstrated that the perceived strength of this phenomenon could be quantitatively mapped onto a psychological stickiness scale derived from common viscoelastic materials, showing a significant correlation between adjusted break distances and scale values. Together, these results suggest that the spatial extent of visually induced resistance to separation serves as a powerful cue for stickiness perception. The present findings provide new insights into how humans visually infer material stickiness in interactive situations and offer a potential framework for pseudo-haptic applications that evoke tactile qualities through visual feedback alone.
I describe some interesting visual phenomena in the work of the artist Robert Fones, including combinatorial use of simple forms to generate three-dimensional shapes, a preference for lighting from overhead and to the left, the convex-concave ambiguity, and subtle but effective cues to lighting direction.
Symbolic numerical thinking is a signature human cognition, yet its foundations remain unclear. The prevailing perspective holds that numerical abilities build on a non-symbolic visual number sense that extracts numerosity from the environment. However, recent evidence suggests a sensorimotor number system also tracks the numerosity of internally self-generated actions. Whether this system supports the development of mathematical skills is unknown. In a series of psychophysical tasks, we measured precision (Weber fraction) for estimating, without counting, the number of (i) self-generated hand actions, (ii) visual-temporal flashes, and (iii) dot ensembles. Precision in the action-based numerosity estimation task explained about 30% of the variance in mental calculation ability — three and 15 times higher than spatial and temporal visual numerosity, respectively. This link remained strong even after regressing out the variance explained by natural development (age), verbal and non-verbal reasoning, non-numerical motor abilities, and visual numerosity estimation precision (R 2 ≈ 26%). These findings provide the first evidence for a specific link between the sensorimotor number system and mathematical competence, suggesting a foundational role of sensorimotor numerical processes in the development of symbolic human numerical cognition.
Anaglyphs are displays in which the left and right eye images are presented in different colours, such as red and cyan, and they are viewed through filters of the same colours so that each eye sees a different image. They have typically been used to present slightly different images to each eye so that they are seen in relief - stereoscopic depth. Anaglyphs have become increasingly popular as a means for printing and projecting stereoscopic drawings and photographs. The general standard now is for red/left eye, cyan/right eye filters for viewing similarly coloured printed or projected images and these are recommended for viewing the anaglyphs in this article. Despite the disdain for anaglyphs in visual science, they have been used extensively in visual art and education. However, anaglyphs can be constructed that yield displays that would be difficult to produce for refracting or reflecting stereoscopes.
In this article, I briefly review evidence accumulated over the past two decades that number should be considered a primary perceptual attribute. I concentrate primarily on adaptation studies, but also show how these have been reinforced with other psychophysical methods, as well as pupillometry, EEG and imaging studies. There have been at least two major challenges to number being a primary perceptual attribute, and to adaptation itself, which I discuss. I conclude speculating on the functional role of adaptation to numerosity perception, and suggesting areas requiring further research.
Physical touch plays an important role in various forms of immersive entertainment, influencing emotional engagement, presence, and narrative immersion. In this narrative historical review, we explore the significance of direct interpersonal (social) touch in entertainment contexts. This includes theme parks, immersive theater, participatory performance art, and digitally mediated touch (e.g., haptic feedback in virtual reality [VR], gaming, and film). By analyzing examples such as Disneyland character interactions, Sleep No More, and audience participation in The Rocky Horror Picture Show, we examine how physical touch enhances immersion by helping to break the fourth wall and by fostering audience agency. Additionally, we compare direct human touch with digitally mediated touch (e.g., haptic feedback in VR) and discuss their respective advantages and limitations. While digital touch offers flexibility and scalability, it often lacks the warmth (both literally and metaphorically), texture, and emotional nuance of actual human interaction and can struggle to reproduce the social meaning and attribution that shape affective touch. The review also highlights a number of the key challenges and boundary conditions in implementing physical touch in the context of entertainment, such as cultural variations in norms and comfort around interpersonal touch, privacy/consent concerns, hygiene concerns, and technical constraints. Future research directions include the integration of physical touch with emerging technologies, personalization of touch-based experiences, and the role of multisensory interactions in enhancing immersive storytelling. Understanding the mechanisms and impact of physical touch in entertainment can inform the design of future multisensory experiences, increasing audience engagement and emotional connectivity while minimizing harm and exclusion.
Self-face representation refers to an internal image of one's own face that does not necessarily match its physical properties. A previous study showed that remembered facial features located centrally or on the right side, such as the nose and right eye, tend to shift rightward. However, this rightward bias may result from using the right index finger to report locations. The present study examined whether the bias would occur when participants used the left index finger, following Mora et al.'s procedure in which participants, with their eyes closed, pointed to locations on a transparent acrylic board as if the designated facial features were projected in parallel in front of the board. Twenty-eight participants pointed to designated facial features using either their right or left index finger. The reported locations were recorded digitally and compared with the actual feature locations. When using the right finger, a rightward bias appeared for all central and right-side facial features. When using the left finger, all left-side facial features shifted leftward, indicating a leftward bias. Importantly, the rightward bias remained for all right-side facial features. These results suggest that the bias reflects both a general tendency toward rightward shifting and an artifact related to the side of the reporting finger.
The slimming effect of striped clothing has long been a research topic in the field of visual perception. Some studies have supported the Helmholtz illusion, which suggests that clothing with horizontal lines makes a person appear thinner than clothing with vertical lines. However, other studies argued that these experiments lacked ecological validity, as it seemed unlikely that stimuli with vertical and horizontal stripes were present concurrently. Therefore, perceptual anchoring should be incorporated into the experimental procedure. While previous studies used only pencil stripes as the research object, this study employed both pencil and equidistant stripes, introducing five different stripe spacing types. This study conducted three comparisons regarding the perception of body image in striped clothing using a survey (n = 214): Experiment 1 identified the horizontal style that appears the slimmest; Experiment 2 identified the vertical style that appears the slimmest; Experiment 3 compared the effects of horizontal and vertical stripes across five garment styles on body image perception, including which style makes the body look slimmer, enhances the figure more effectively, and is more visually appealing. The results show that the horizontally pencil-striped dress (1 × 2 h in our nomenclature) is perceived as the slimmest. Second, while a pencil stripe pattern may make the body appear slimmer when oriented horizontally, an equidistant stripe pattern may do this when oriented vertically instead (1 × 1 v from back). Third, there are slight differences between the perceptions of males and females.
Gloss perception depends on several surface properties, but most studies measure these effects only one or two at a time. Here, we test whether a three-dimensional version of maximum likelihood conjoint measurement (3D-MLCM) can be used to capture the combined influence of multiple cues on gloss. Observers judged which of two surfaces looked glossier while specular reflectance, albedo, and bumpiness were varied together. The additive model showed clear and reliable contributions of both albedo and bumpiness in addition to specular reflectance, and model comparisons confirmed that these cues significantly affected gloss judgments. The full model further revealed that these effects change with gloss level: bumpiness strongly influenced perceived gloss at low specular reflectance but had little effect at high gloss levels. These results show that 3D-MLCM provides stable, interpretable measurements and is a practical method for studying complex interactions between visual features that influence visual appearance.
Patrick Hughes' "Reverspectives" typically have a three-dimensional structure consisting of protruding, truncated pyramids but they appear to recede into the distance because of the perspective images on the sides of the pyramids. More recently, PH has created "Solid Hollows" which have a receding (hollow) three-dimensional structure but they appear to protrude. In this paper, we have attempted to describe both the similarities and differences between "Reverspectives" and "Solid Hollows". We conclude that perspective is not a mere "secondary cue" (Helmholtz, 1910) in the perception of Reverspectives but instead perspective dominates over binocular disparity when the viewing distances are greater than 50-100 cm. For "Solid Hollows", perspective also plays a role in the (perceived) reversed depth, as does the visual system's inherent bias for seeing objects as convex.
Emotion perception of the target face within an emotional crowd is influenced by the intensity of surrounding emotional faces. The present study investigated whether participants perceived the target face's emotional intensity as more aligned with the crowd's emotional intensity (i.e., assimilation effect of facial emotion perception in an emotional crowd). Participants estimated the emotional intensity of the target face within a crowd consisting of multiple emotional faces (angry/happy crowd in Experiment 1 and Experiment 3; angry/happy/fearful crowd in Experiment 2). Results across the first two experiments established a consistent assimilation effect: when embedded within a low-intensity angry or fearful crowd, negative target faces were perceived as less intense than their objective baseline. After accounting for potential confounds related to facial morphological features, Experiment 3 replicated these findings, confirming the stability of this perceptual bias. Notably, this assimilation effect was valence-specific, appearing consistently for negative emotions but failing to emerge for happy faces. Additionally, we found that individuals with a higher level of depression tended to underestimate the happy intensity of the happy face within a happy crowd. Across three experiments, the present study revealed that the negative face's emotional intensity perception within a negative crowd exhibited an assimilation effect.
Visual illusions serve as a window into the altered perceptual experiences of individuals with psychiatric disorders. One such is the induced Roelofs effect, where the perceived position of a small stimulus is shifted toward the midline of a distractor frame surrounding the stimulus, as the shift is more pronounced in individuals with schizophrenia. The present work extends the induced Roelofs effect assessment to bipolar disorder. Healthy controls, patients with bipolar disorder, and patients with schizophrenia were shown a dot stimulus placed inside a frame whose horizontal position could vary, and they were asked to determine whether the dot position was to their left or to their right. The induced Roelofs effect was minimal in healthy controls, large in schizophrenia, and intermediate in bipolar disorder. No association between the effect size and psychotic symptomatology or cognitive abilities was found. Yet, a nonlinear, concave association was found between the total pharmacological load and the illusion size. The results suggest that the illusion is related to alterations in sensory processing, which are common to both bipolar disorder and schizophrenia, hence showing their potential utility in clinical evaluations, which currently tend to overlook the sensory domain.
The present study provides evidence that simple manual reaction time (RT) can be shortened by task irrelevant Kanizsa-like illusory figures emerging as completed perceptual units in the observer's visual system. This type of behavioral effect allows to evaluate the role of a perceived figure constituted by brightness enhancement, illusory contours and depth stratification by maintaining constant retinal size and average luminance of the inducers in modulating RT. Using two different versions of the inducers, with the same retinal size and different average luminance, we found that simple RT was shortened by the presence vs absence of the figure with significant faster response in the illusory condition than no-illusory condition in the two versions of the inducers. These results confirm previous works that provide evidence on the relationship between simple RT and perceptual/phenomenal features.
In filmmaking, a neutral face paired with an emotional context can convey a congruent emotion-a phenomenon known as the Kuleshov effect. However, past research has yielded mixed findings on the existence of the Kuleshov effect, possibly due to methodological variability; we therefore implemented a boundary-test paradigm that combined normed static context images with dynamic facial stimuli separated by an explicit context-rating step to examine how visual context shapes the evaluation and categorization of faces under such conditions. We hypothesized that positive context would elevate facial valence ratings (and vice versa), while evoking different-than-neutral emotions in a neutral face when categorized. Thirty-two participants first rated the valence of a context image on a 7-point Likert scale. They then viewed a video of a neutral face, evaluated its valence on the same scale, and explicitly categorized the expression by selecting one of five predefined emotion labels (neutral, angry, happy, sad, disgusted). Analyses using linear mixed-effects models confirmed that positive contexts led to higher facial valence ratings, while negative contexts led to lower ones; by contrast, multinomial regression revealed no effect of context on emotional categorization. Our findings suggest that while visual context can bias evaluative judgments of facial expressions, it does not necessarily alter their emotional categorization under conditions where cinematic continuity is absent, highlighting the boundaries of the Kuleshov effect in line with previous studies.
Gloss perception, a crucial visual ability, poses computational challenges for human and machine vision when estimating surface glossiness. The Dichoptic Color Difference Threshold (DCDT) is a quantitative metric to assess the minimal discernible color variation in binocular luster perception. In this study, we investigated the relationship between binocular luster and color hue, color difference, and luminance factors by quantifying and measuring DCDTs under binocular equivalent luminance conditions. Additionally, we fitted a quadratic logarithmic function model to describe the association between binocular luster and luminance factors. The experiments and data analysis presented in this article demonstrate that luminance significantly influences binocular luster. These research findings provide robust support for luster reproduction in three-dimensional system design.
Both the art of photography and the art of magic are replete with surreal body illusions. In this short note, we illustrate how many of these illusions can be understood as variants of the illusion of absence, in which the space behind an occluder is experienced as compellingly empty.
