Earlier research has shown that seven-month-old infants prefer to look at real objects over their referents. Which visual cues determine that preference? Motivated by research on adult observers highlighting the significance of motion parallax over other depth cues contributing to a sense of presence and place, we tested the hypothesis that motion parallax alone is sufficient to cause preferential looking to real objects in infants. We presented pairs of displays of toys in different formats: (a) The real three-dimensional toy; (b) a realistic image of that toy presented on screen; (c) the same image, but with added depth-from-motion-parallax. Infants preferred (a) over (b) (57% vs. 43%,  < .01) and (c) over (b) (52% vs. 48%,  < .05), but showed no significant preference between (a) and (c) (51% vs. 49%, n.s.). This supports the hypothesis that motion parallax alone can induce a looking preference comparable to that observed for real objects.

The Flying Bluebottle Illusion is a compelling example of how the perceived trajectory of moving objects can be greatly influenced by other motion sources in the visual scene. In this article, we present a series of simplified variants of the Flying Bluebottle Illusion in which the true motion of a target is a circular orbit around a central point. However, when a similar but offset orbiting motion trajectory is added to a set of surrounding inducers, the perceived trajectory of the target is drastically altered in both extent and direction. In other words, the perceived orbiting motion of the target is "pulled" and distorted by the orbiting motion of the inducers. For simplicity's sake, we refer to the illusory effect revealed by these dueling orbits as the Dueling Orbit Illusion. These simplified variants lend themselves to empirical study with resultant effects that can be readily modeled. Here, we present a series of case examples for how the parameters of the stimuli may be varied to yield predictable effects, describe a straightforward computational model for quantifying the magnitude of the contextual influence, and discuss how the model may be leveraged to gain insight into the phenomenon of induced motion across a range of within and between observer domains.

When human observers are asked to describe the shape of a surface, they often identify an arrangement of surface features like bumps, dimples, ridges, or valleys. The central hypothesis of the present research is that the perceptual representation of three-dimensional shape has a graph-like structure that is defined by patterns of surface curvature, and that this is the structure that artists depict when they produce line drawings of objects. Two experiments were performed, in which observers marked the boundaries of bumps on a shaded surface, or the locations of ridges and valleys. Although they were not specifically instructed about where those features were located, the observers' responses corresponded quite closely with the curvature extrema on each depicted object, and their judgments exhibited a high degree of constancy over changes in the pattern of illumination. The relationship is much weaker between the perceived locations of ridges and valleys and the local extrema of luminance in an image. Although variations of luminance are strongly influenced by the pattern of surface curvature, they are also influenced by local variations in illumination caused by multiple light sources, cast shadows, or indirect reflections. Human observers can somehow distinguish between those two components of luminance variation, but the visual information that makes that possible has yet to be determined.

[This corrects the article DOI: 10.1177/20416695251315382.].

This study investigates the phenomenon of magnification illusion, where the perception of perspective and optical slant angles changes when a scene is magnified. Our findings indicate that magnification influences these angles differently depending on location, which suggests that the illusion might be caused by changes in three-dimensional (3D) interpretation. Our findings reveal that the change of perspective angle interpretation primarily occurred when the stimuli were on the ground and sidewall but not those on the ceiling. Specifically, stimuli on the ceiling exhibit a significant underestimation of optical slant angles, while the perspective angle remains relatively stable. We developed a mathematical model based on the hypothesis of changes in 3D interpretation, which aligns well with our data. It was found that the interpretation of the perspective angle and the optical slant angle changes when a scene is magnified as indicated by the proposed relationship. This research provides the characteristics underlying spatial perception and its alteration under magnification and relative location, with potential applications in virtual reality and augmented reality system designs.

The image intensity depends on the illumination, the reflectance properties of objects but also on the reflectance and absorption properties of any intervening media. In this study we present observers with glossy objects behind partially transmissive materials. The transparent layer causes an achromatic color shift and compression in luminance contrast, which can affect the perception of the specular reflections of the object behind the layer. In two distinct experiments, we examine how an achromatic color shift and the compression of luminance contrast affect perceived gloss. Thanks to the maximum likelihood conjoint measurement paradigm, we estimate the contamination of different transparent layers on perceived gloss. In the follow-up experiment, observers were asked to match the albedo and the gloss of surfaces seen in plain view to surfaces seen behind a transparent layer. Our results indicate a high degree of gloss constancy with some small but significant contribution of the transparent layer when estimating gloss, especially in the case of light-colored transparent layers. Overall, gloss is significantly overestimated.

Illumination conditions inside and outside cast shadows typically differ significantly in both intensity and in chromaticity. However, our daily experiences suggest that we generally have no difficulty in stably perceiving surface color in cast shadows. In this study, two experiments were conducted to measure the extent to which color constancy holds within cast shadows. We constructed a scene with colored hexagons illuminated by two projectors simulating "sunlight" and "skylight." Part of the scene included a cast shadow, illuminated only by the skylight, where a subjective white point was measured. We also created a condition in which a cast shadow was not perceived as a shadow. Results showed that color constancy generally holds well in shadows, and the color of skylight had varying effects depending on observers. Perceiving a cast shadow as a shadow had no effect. Overall, these findings are consistent with our daily experiences, in which we stably judge objects' color even within cast shadows.

A multimodal Ganzfeld (MMGF) consists of homogeneous stimulation in both the visual and auditory modalities. Exposure to this unique perceptual environment can elicit the awareness of hallucinatory percepts. The nature of these hallucinatory percepts, and specifically the frequency of visual, auditory and multisensorial hallucinations, remains unclear. In this study, an MMGF refers to the stimulation paradigm itself. The perceptual experiences elicited, however, can be unimodal (occurring in one modality), multisensory (simultaneous but thematically unrelated across modalities), or multimodal (thematically integrated across modalities), allowing us to assess multisensory integration in the MMGF. Employing a multimethod approach in which we combine quantitative and qualitative measures, we conducted three experiments, using a between-subjects design with three noise conditions, that is, no-noise, white-noise, and brown-noise. Experiments 1 and 2 were conducted in a laboratory Ganzfeld (GF) space, Experiment 3 was conducted in a GF art installation in a museum context. We conducted half-open interviews, analyzed using inductive content analysis, to grasp the subjective experience and assess congruency of visual and auditory hallucinations. We found that visual hallucinations were frequently reported, but auditory hallucinations were less common. The most consistently reported auditory hallucinations, and importantly, multisensory integrated hallucinations, were water-related, suggesting a potential influence of noise, particularly brown noise, possibly due to its resemblance to water sounds. Our findings also indicate a predominantly unimodal focus on the visual aspect among participants, alongside instances of attention switching between modalities.

Numerous studies have explored the mechanisms of heading estimation from optic flow and ensemble coding in other features, yet none have examined ensemble coding's role in heading estimation. This study addressed this gap through two experiments. Participants sequentially viewed three (experiment 1) or five/seven (experiment 2) optic flow-simulated headings, then reported specific directions. Results revealed that individual heading accuracy declined with increasing numbers, while estimates closely matched ensemble representations, demonstrating ensemble coding in heading estimation. Notably, ensemble coding accuracy remained unaffected by heading quantity, indicating its capacity-free nature-unlike capacity-limited individual heading processing. The discovered summary statistics of motion may help us to better understand the navigation in complex environments (e.g., how pedestrians/drivers judge their self-motion directions), which could potentially contribute to real-world implications.

The color appearance of #TheDress image varies across individuals. The color of pixels in the image distributes mostly in blue-achromatic-yellow color direction, and so are the perceived color variations. One of the potential causes is differences in the degree of perceiving light-blue pixels as a part of white clothing under a skylight, referred to as "blue bias." A deep neural network (DNN) application was used to simulate individual differences in blue bias, by varying the percentage of such scenes in the training-image set. A style-transfer DNN was used to simulate a "color naming" procedure by learning pairs of natural images and their color-name labels as pixel-by-pixel maps. The models trained with different ratio of blue-bias scenes were tested using the #TheDress image. The averaged results across trials showed a progressive change from blue/black to white (gray)/gold, indicating that exposure or attention to blue-bias scenes could have caused the individual differences in the color perception of #TheDress image. In an additional experiment, we manipulated the relative number of artificially blue- or yellow-tinted images, instead of varying the ratio of blue-bias scenes, to train the DNN. If the blue-bias scenes are equivalent with blue-tinted images of scenes taken under daylight, this manipulation should yield similar result. However, the resulting outputs did not produce a white/gold image at all. This suggests that exposure to skylight scenes alone is insufficient; the scenes must contain unequivocally white objects (such as snow, white clothing, or white road signs) in order to establish a "blue bias" in human observers.

Humans use distinct exploratory procedures (EPs) in active touch, which are typically specialized for materials with particular properties: for example, pressing for deformable objects such as cushions, or stroking to test a fabric's smoothness Further, humans can use abstract visual priors for fine-tuning of exploratory movement parameters such as exploration direction. We here test the usage of visual priors in the planning of material-specific EPs, using real-life materials and a naturalistic visual virtual reality environment. We show that humans are better at selecting specialized EPs at initial touch when they have access to valid prior visual information on the material: They used specialized EP earlier, with higher probability, and explored materials for a shorter time. We conclude that visual prior information increases the efficiency of haptic explorations by anticipatory planning of appropriate movement schemes.

We discovered a new type of assimilative color induction. An achromatic target with a white background was placed in the center of a concentric chromatic gradient that caused the glare effect. The target frequently appears to be in the same hue as the gradient. We discussed lower-level factors such as lateral inhibition and spatial summation functions, and higher-level factors such as illumination estimation.

This study investigates how the method used by participants to assess the beauty of pictures influences their preference for the compositional rules of symmetry, balance, and proximity. The hypothesis that production methods (actively arranging picture elements) prompt a local perspective, favoring proximity, while evaluation tasks (rating precomposed pictures) elicit a global perspective, favoring symmetry and balance, was tested in two experiments. Experiment 1 demonstrated that (positional) symmetry was preferred over balance, and balance over proximity, when participants rated precomposed pictures. Experiment 2, employing a production method with movable elements, showed a frequent use of proximity, yet also a tendency toward (positional) symmetry. The combined results indicate that assessment methods substantially impact the preferred composition rules.

The rise of social media has raised concerns about its addictive potential and impairments in mental health and cognitive functions, including distortions in time processing. Emerging evidence suggests social media addicts tend to misestimate the amount of time spent using social media, hinting at possible problems with their cognitive time-processing. This study aimed to investigate the impact of social media addiction on basic time perception using controlled experimental paradigms. Forty participants scoring ≥24 on the Bergen Social Media Addiction Scale with ≥5 hr daily usage were recruited, alongside 40 controls. After excluding individuals craving, fear of missing out for social media, or test anxiety during experiment, final samples included 36 addicts and 37 controls. Time reproduction (motor timing) and bisection (perceptual timing) tasks were administered, distinguishing subsecond (<1 s) and suprasecond (>1 s) intervals. Tasks used neutral gray stimuli to avoid social media cues and included pretask rest to control physiological arousal. Social media addicts exhibited significant deficits in suprasecond bisection task, demonstrated by lower subjective equality points (1,430.69 vs. 1,549.32 ms) and higher Weber ratios (0.41 vs. 0.29), indicating both time overestimation and reduced time sensitivity. No significant group differences were observed in reproduction tasks or in subsecond bisection task. These findings establish that social media addiction selectively impairs suprasecond perceptual timing, characterized by overestimation and diminished sensitivity. These findings establish a novel cognitive deficit linked to addictive social media use, with potential clinical implications for intervention strategies targeting distorted time processing.

Julesz constructed stereograms in which surfaces in depth could be seen with two eyes but not with either eye alone. He noted that such enclosed surfaces in depth never occur in natural scenes. In contrast, extended stereoscopic surfaces are a natural feature of binocular vision. Examples of constructed textured surface stereograms are presented as anaglyphs. They satisfy the criterion of revealing depth seen with two eyes which is concealed from each eye alone. A wide range of carrier patterns can be employed to construct complex stereoscopic surfaces. Stereoscopic inclusions can be embedded within modulated surface depths in the same anaglyphs, and conventional stereoscopic images (photographs) can be incorporated within constructed stereograms. Textured surface stereograms offer the possibility of extending the artistic expression of stereoscopy.

To localize tactile events in external space, our perceptual system must transform skin-based locations into an external frame of reference. Such a transformation has been reported to involve reference frames that are unrelated to tactile sensations, such as eye position, which supports the idea that a visual reference frame is a single unified frame of reference for transforming spatial information from all sensory modalities. However, it remains unclear how tactile events are perceptually localized during saccadic eye movements. In this study, we presented a single tactile stimulus at a fixed location on the skin and investigated the time course of its localization before, during, and after a saccade. Participants reported the perceived location of the tactile stimulus in a visually aligned virtual space. We found that the tactile stimulus was mislocalized in the direction of the saccade. This mislocalization appeared even before the presentation of the saccade target and continued until 500 ms after saccade onset. These findings demonstrate that tactile localization is influenced by saccade planning or preparation and suggest that the time course of tactile localization during a saccade may differ from previously reported patterns of visual localization during a saccade.

When climbing a mountain, one is sometimes surprised at how the mountain turns out to be much taller than one initially believed. Wishful thinking easily comes to mind as an explanation for this, but we illustrate how this misjudgment may also be explained as a consequence of the perceptual experience of amodal volume completion.

Some occluders evoke the compelling impression that the space behind them is empty. Stage magicians use this illusion of absence to produce objects out of thin air. The generic view principle predicts that the illusion of absence should increase with decreasing occluder size. We investigated this prediction in experiments where participants saw a partly occluded scene and the same scene without the occluder, revealing a piece of fruit. They then rated (1) how easy it felt to imagine that the fruit was hidden behind the occluder and (2) how likely they thought it was that the fruit was hidden behind the occluder. Both ratings increased with increasing occluder area. This shows that the illusion of absence increases with decreasing occluder area, as predicted by the generic view principle. These findings could provide a starting point for future studies aiming to understand and prevent road accidents involving obstructions of view.

Understanding others' listening experiences is an instance of social metacognition. We investigate attributed listening experiences to fictional others in two online experiments involving two groups, young and older adults with normal hearing. We assessed the similarity between the judgement they gave for themselves and for two fictional characters (same or different age), with respect to listening experiences and effort required across various listening scenarios. In Exp. 1, all characters were described as having normal hearing; in Exp. 2, we introduced one additional older character with hearing loss. In both experiments, younger adults judged the older characters as experiencing more effort, irrespective of hearing loss. Instead, older adults reported to experience less effort than older characters, irrespective of characters' hearing status and judged themselves closer to the young character. These findings show disparities in metacognitive auditory perspective taking in young and older adults, documenting a potential self-serving bias of older adults.

Face pareidolia refers to perceiving facial features on inanimate objects. Previous studies have identified gender differences in pareidolia, but the factors behind these differences remain unclear. This study examined potential influences, including task requirement, low-frequency information encoding ability, and cognitive style. University student participants reported what they saw in face-like object images and rated their face-likeness. A delayed matching task with blurred faces assessed encoding ability, and the Navon task examined cognitive style. Results showed that gender differences were influenced by task demands: women were more likely than men to perceive faces in objects, and this was not related to facial configuration processing. Additionally, a global processing tendency predicted higher pareidolia in women but not in men. Our findings suggest that gender differences in pareidolia are shaped by judgment criteria, with women adopting more relaxed criteria. This research contributes to understanding gender differences in social cognition.

Shading is an important monocular cue for three-dimensional (3D) perception, whereby 3D shape can be inferred from shading patterns across an object, in a process termed . Shape-from-shading has been characterised as a pre-attentive process that occurs in parallel across the visual field. Recent evidence, however, has challenged this notion, suggesting that it consists of an early pre-attentive process and a later stage of processing that is reliant on top-down attention. Here, we use event-related potentials (ERPs) to test this claim whilst participants were instructed either to ignore or to attend to shaded stimuli that could be perceived as two-dimensional (2D) and 3D. We found that 3D stimuli evoked a larger N1 component than 2D stimuli in both attended and unattended conditions, implying an early, pre-attentive processing stage in shape-from-shading. This activity was lateralised to the right hemisphere when participants attended to the stimuli, in accordance with the right hemisphere advantage in top-down attention. Further, when participants attended to the stimuli, a larger N2 component for 3D compared to 2D shape was found, suggesting a late, top-down process for identifying 3D shape. These findings provide evidence for two distinct stages of processing for shape-from-shading and suggest that attention is necessary for the perception of shape-from-shading.

In dynamic visual scenes, many materials-including cloth, jelly-like bodies, and flowing liquids-undergo non-rigid deformations that convey information about their physical state. Among such cues, we focus on deformation-based motion-defined as the spatial shifts of image deformation. Studying deformation-based motion is essential because it lies at the intersection of motion perception and material perception. This study examines how two fundamental properties-spatial frequency and displacement speed-jointly shape the perception of deformation-based motion. We focused on these parameters because, in luminance-based motion perception, spatial frequency and displacement speed have been shown to critically influence motion sensitivity. Across three experiments using sequentially deformed 1/f noise images as a neutral background, we systematically manipulated the spatial frequency components of the deformation and the speed at which these deformations were displaced. Results showed that direction discrimination performance was strongly modulated by the interaction between spatial frequency and displacement speed. Suppressing local deformation cues improved discrimination at low frequencies, suggesting that local signals may interfere with global motion inference. These findings reveal how the spatial structure and dynamics of image deformation constrain motion perception and provide insights into how the brain interprets dynamic visual information from non-rigid materials.

When interacting with technology, humans often deal with delays between an action and the desired action outcome. Through delay adaptation these delays will become less detrimental to visuomotor performance over time. Delay adaptation has been shown for a variety of tasks and control modes, from simple button presses causing a beep or flash to continuous target-tracking tasks. Here we investigated whether the delay adaptation is specific for the control mode used, when the task itself remained unaltered. To this end, participants performed a target tracking task in which they controlled a cursor item either by moving a stylus on a graphics tablet or by pressing the arrow keys on a keyboard. We found that delay adaptation occurred for both these types of control modes, but observed no transfer to the other control mode. This indicates that delay adaptation is specific to the control mode used during adaptation.

In real life, people perceive nonexistent faces from face-like objects, called face pareidolia. Face-like objects, similar to averted gazes, can direct the observer's attention. However, the similarities and differences in attentional shifts induced by these two types of stimuli remain underexplored. Through a gaze cueing task, this study compares the cueing effects of face-like objects and averted gaze faces, revealing both commonalities and distinct underlying mechanisms. Our findings demonstrate that while both types of stimuli can elicit attentional shifts, the mechanisms differ: averted gaze faces rely on processing local features like gaze direction, whereas face-like objects leverage their global configuration to enhance attentional shifts by triggered eye-like features. These findings advance the understanding of the processing mechanisms underlying the perception of face-like objects, and how the brain represents facial attributes even when physical facial stimuli are absent. This study provides a valuable theoretical foundation for future investigations into the broader applications of face-like stimuli in human perception and attention.

This article explores audiovisual associations within the context of contemporary and experimental music practices, particularly focusing on sound-based music. While extensive studies exist on crossmodality in relation to traditional music genres (such as classical instrumental music), the perceptual potential of sound-based music remains an underexplored field of psychological research. In an online procedure, 152 participants were exposed to six musical excerpts from spectralism and electronic-glitch music and were asked to rate the extent to which each audio matched with six ad hoc generated black and white abstract images. Statistical analysis revealed that ratings were highly consistent across participants, indicating that they may rely on a shared set of implicit perceptual criteria rooted in Gestalt and morphodynamic features common to both auditory and visual stimuli. In particular, smoothness, continuity, numericity, symmetry, and spectrotemporal dimensions emerged as the primary factors influencing the association ratings. We discuss the implication of these findings both for crossmodal research and musicology, and suggest some directions for future research in audiovisual associations using sound-based music.

A large and a small disk with radii and , side by side, exchange positions repetitively at 1.33 Hz. The motion is ambiguous. If < 0.8 then observers perceive a single large disk jumping back and forth across a small static disk. But if / > 0.8, observers perceive two static disks that expand and contract in counter phase, with no motion across the gap between the disks. Observers respond to the movement of the , which is greatest when < 0.8.

Two spots moving simultaneously along the same path in opposite directions can appear either to bounce or stream. Bouncing is promoted by spots that turn back and retrace their path. Streaming is promoted by same-size spots, moving along a straight path and viewed peripherally. Both percepts are driven by Gestalt grouping.

Pilots show superior visual processing capabilities in many visual domain tasks. However, the extent to which this perceptual advantage extends to multisensory processing requires validation. In this study, we examined multisensory integration of auditory and visual information in both pilot and control groups, utilizing two sound-induced flash illusions (SIFI) tasks: the fission illusion, where one flash coupled with two beeps is perceived as two flashes; and the fusion illusion, where two flashes with a single beep are perceived as one flash. Sixty-six participants were instructed to discern whether they observed one or two flashes while discounting irrelevant auditory beeps, across six conditions: one flash (1F), two flashes (2F), one flash/one beep (1F1B), one flash/two beeps (1F2B), two flashes/one beep (2F1B), and two flashes/two beeps (2F2B). We varied six stimulus onset asynchronies (SOAs) between auditory and visual events (25-150 ms) to assess the participants' temporal binding window (TBW). Signal detection theory was employed to analyze the group differences in illusion reports. The findings suggest that, while pilots are less susceptible to SIFI in either fission or fusion conditions, they only exhibit narrower TBW in the fusion condition, where pilots demonstrated a more gradual change in their susceptibility as SOA increases. In the fission condition, the group difference was primarily driven by visual sensitivity, whereas in the fusion condition it also likely reflected pilots' distinct multisensory integration mechanisms. Two alternative possibilities are discussed to explain the group differences and the different multisensory integration patterns in fission and fusion conditions.

Travelling longitudinal waves provide a novel visual motion stimulus that supports the perception of stereoscopic travelling waves from a phased array of sinusoidal oscillations.

Olfactory function plays a vital role in daily life but tends to decline with age, affecting health and wellbeing. While previous studies suggest a link between physical activities and olfactory function in older adults, the relationship between cognitive activity and olfactory function remains unclear, as do the combined effects of both activities. This cross-sectional study examined associations between physical and cognitive activity and three domains of olfaction (identification, sensitivity, and memory) in 583 community-dwelling older adults. Both types of activity were positively associated with overall olfactory performance. Physical activity exhibited the strongest link with olfaction identification, while cognitive activity was more closely related to olfaction memory. Furthermore, participants engaging in moderate-to-high levels of both activities achieved the best overall olfactory scores. These findings suggest that a combined lifestyle of physical exertion and cognitive engagement may help preserve olfactory function in aging, with implications for autonomy, safety, and quality of life.