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Johan Wagemans

Johan Wagemans
KU Leuven | ku leuven · Research unit for Experimental Psychology

Professor

About

721
Publications
153,471
Reads
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13,104
Citations
Introduction
I am interested in perceptual organization (e.g., grouping, figure-ground, texture, depth, shape, objects). Specifically, I want to contribute to understanding why things look as they do, at different levels (e.g., phenomenological, psychophysical, computational, neural, ecological). I am also interested in applications of our insights in autism, arts, and sports. For downloads of our publications see www.gestaltrevision.be

Publications

Publications (721)
Poster
Full-text available
The work presented in this poster is still in progress. It provides an example of a modelling procedure for analysing eye movements recorded during art exhibitions with Hidden Markov Models and clustering. I haven''t figured out yet the optimal modelling procedure, including the parameters of the analysis. In particular this poster explores the use...
Poster
Full-text available
The work presented in this poster is still in progress. It provides examples of modelling procedures for analysing eye movements recorded during art exhibitions with Hidden Markov Models and clustering. I haven''t figured out yet the optimal modelling procedure, including the parameters of the analysis. In particular, this poster presents the analy...
Article
Full-text available
Perception of simple temporal patterns has been shown to rely on accentuations in terms of intensity, pitch, or timbre, but also on grouping according to runs of the same events (intervals between successive sounds or light flashes) or significant gaps between them (Garner in The processing of information and structure. Lawrence Erlbaum, 1974; Preu...
Preprint
Full-text available
Gestalt psychologists posited that we always organize our visual input in the best way possible under the given conditions. Both weakening or removing unnecessary details (i.e., leveling) and exaggerating distinctive features (i.e., sharpening) can contribute to achieve a better organization. When will a feature be leveled or sharpened, however? We...
Article
Full-text available
How we perceptually organize a visual stimulus depends not only on the stimulus itself, but also on the temporal and spatial context in which the stimulus is presented and on the individual processing the stimulus and context. Earlier research found both attractive and repulsive context effects in perception: tendencies to organize visual input sim...
Preprint
Full-text available
For many decades, psychologists have acknowledged the importance of using psychological scaling rather than physical scaling when assessing similarity between stimuli or differences in reactions to stimuli. Most of the existing literature focuses on psychological scaling as an explanatory variable rather than as something that needs explanation its...
Article
An eye-tracking and questionnaire study was set up in collaboration with the Van Abbemuseum (Eindhoven, The Netherlands) to investigate the perception and appreciation of three Frank Stella paintings from the 60s ( Tuxedo Park Junction and Effingham I from the collection of the museum and a hand-painted replica of Hiraqla Variation II ). Effingham...
Preprint
Full-text available
Do individuals prefer stimuli that are ordered or chaotic, simple or complex, or that strike the right balance of order and complexity? Earlier research mainly focused on the separate influence of order and complexity on aesthetic appreciation. When order and complexity were studied in combination, stimulus manipulations were often not parametrical...
Article
Previous studies provided evidence in support of attention operating in three-dimensional space, and the iterative and multistage nature of organizational processes in relation to attention and depth. We investigated depth perception and attentional demands in grouping organizations that contain blur as a depth cue. Contrary to previous studies, in...
Article
Full-text available
Visual perception is the result of a highly complex process depending on both stimulus and observer characteristics and, importantly, their interactions. Generating robust theories and making precise predictions in light of this complexity can be challenging, and the interaction of stimulus- and observer-related effects is often neglected or unders...
Article
Full-text available
The purpose of the present note is to draw attention to the potential role of a recently discovered visual illusion in creating traffic accidents. The illusion consists in a compelling and immediate experience that the space behind an occluding object in the foreground is empty. Although the illusion refers to a region of space, which is invisible...
Article
Full-text available
Background Children with cerebral visual impairment (CVI) present heterogeneous visual orienting functions (VOF) and higher-order perception. Multiple assessment methods evaluate CVI, but the relations between them remain unclear. Aim To investigate the relations between VOF and (1) daily life behaviour and (2) visuoperceptual tests in children wi...
Article
Full-text available
Children with cerebral visual impairment (CVI) exhibit a very heterogeneous clinical visuoperceptual picture, which implies that a targeted individualized and adaptive therapy is necessary. Serious games for CVI are limited, especially those that train multiple visuoperceptual skills in an individualized and adaptive manner without the frequent man...
Article
Full-text available
Perceptual organisation is hypothesised as a key in the perception and appreciation of abstract art. Here, we investigated how relational and compositional features affected the perception and aesthetic appreciation of Black Square and Red Square by Kazimir Malevich (1915). We studied how (i) the presence and obliquity of the red square and (ii) th...
Article
Full-text available
Background According to Bayesian hypotheses, individuals with Autism Spectrum Disorder (ASD) have difficulties making accurate predictions about their environment. In particular, the mechanisms by which they assign precision to predictions or sensory inputs would be suboptimal in ASD. These mechanisms are thought to be mostly mediated by glutamate...
Poster
Full-text available
How we perceive a visual form not only depends on the currently presented shape, but also on the temporal context in which it is shown. Earlier research found both attractive and repulsive context effects in perception. Tendencies to see the current stimulus similar to how the previous stimulus was seen (i.e., hysteresis, attraction) co-exist with...
Article
Lay abstract: We have an internal representation of the world that guides our behavior, helps us predicting what comes next and therefore, reducing uncertainty. For instance, after hearing the noise of a door opening, we usually expect to see a person appearing, whose features differ depending on the context. In this example of associative learnin...
Article
Full-text available
We review and revisit the predictive processing inspired “Gestalts as predictions” hypothesis. The study of Gestalt phenomena at and below threshold can help clarify the role of higher-order object selective areas and feedback connections in mid-level vision. In two psychophysical experiments assessing manipulations of contrast and configurality we...
Article
Full-text available
Generative adversarial networks (GANs) enable computers to learn complex data distributions and sample from these distributions. When applied to the visual domain, this allows artificial, yet photorealistic images to be synthesized. Their success at this very challenging task triggered an explosion of research within the field of artificial intelli...
Article
Full-text available
Categorization of visual stimuli at different levels of abstraction relies on the encoding of relevant diagnostic features present at different spatial scales. We used the Eidolon Factory, an image-manipulation algorithm that introduces random disarray fields across spatial scales, to study how such a process flexibly combines perceptual informatio...
Article
The aim was to develop a visuoperceptual profile schema reflecting visuoperceptual strengths and weaknesses, using neuropsychological tests. Secondly, this schema was used to quantify individual visuoperceptual profiles of children with and without cerebral visual impairment (CVI), and to identify differences in their profiles. Clinical records (20...
Article
Full-text available
Bayesian predictive coding theories of autism spectrum disorder propose that impaired acquisition or a broader shape of prior probability distributions lies at the core of the condition. However, we still know very little about how probability distributions are learned and encoded by children, let alone children with autism. Here, we take advantage...
Article
Full-text available
Current theories propose that our sense of curiosity is determined by the learning progress or information gain that our cognitive system expects to make. However, few studies have explicitly tried to quantify subjective information gain and link it to measures of curiosity. Here, we asked people to report their curiosity about the intrinsically en...
Article
Purpose: Published reports suggest that nonoptimal visual search behavior is associated with false negatives in chest x-ray interpretation. Eye movement modeling example (EMME)-based training interventions, that is, interventions showing models of visual search to trainees, have been shown to improve visual search as well as task accuracy. Approach...
Article
The majority of studies showing multisensory attention benefits have focused on brief audiovisual events. Here we examined whether attention benefits can occur for auditory and visual signals that change in synchrony over time. In the first two experiments, we found no evidence that attention was captured more by synchronous compared to asynchronou...
Preprint
Full-text available
How we perceptually organize a visual stimulus depends not only on the stimulus itself, but also on the temporal and spatial context in which the stimulus is presented as well as on the individual processing the stimulus and context. Earlier research found both attractive and repulsive context effects in perception (Snyder, Schwiedrzik, Vitela, & M...
Article
Gestalt psychology has traditionally ignored the role of attention in perception, leading to the view that autonomous processes create perceptual configurations that are then attended. More recent research, however, has shown that spatial attention influences a form of Gestalt perception: the coherence of random-dot kinematograms (RDKs). Using ERPs...
Preprint
Full-text available
Do aesthetic preferences for images of neatly organized compositions (e.g., images collected on blogs like Things Organized Neatly©) generalize across cultures? In an earlier study (Van Geert & Wagemans, 2019), focusing on stimulus and person properties related to order and complexity, Dutch-speaking participants (N = 421) indicated their preferenc...
Preprint
Full-text available
Visual perception is the result of a highly complex process depending on both stimulus and observer characteristics and importantly, their interactions. Generating robust theories and making precise predictions in light of this complexity can be challenging and the interaction of stimulus- and observer-related effects is often neglected or understa...
Article
Full-text available
According to the predictive coding framework, percepts emerge from combinations of sensory input and prior knowledge, whose relative contributions depend on their reliability. Recent predictive coding theories suggest that Autism Spectrum Disorder (ASD) could be characterized by an atypical weighting of priors. Here, we assessed whether individuals...
Article
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that remains poorly understood. Recent predictive coding theories suggest that atypical perceptual learning could play a central role in ASD. Here, we used two behavioral experiments to investigate prior learning and adjustment in ASD. In Experiment 1, 54 adults (31 neurotypical [NT] a...
Article
The occurrence of implicit processing of stimuli during inattentional blindness is still a matter of debate, and a better understanding of this issue can ultimately offer insights on the relation between attention and consciousness. To assess the evidence available in the current debate, in this study we conducted a systematic review of papers that...
Article
Full-text available
The use of technology has been proposed to improve decision-making in sport officials. The implementation of the video Assistant Referee (VAR) in association football is one example of how technology can be used to assist decision making, although its impact remains unknown. In 2195 competitive football matches across 13 countries, the VAR conducte...
Preprint
Categorization of visual stimuli at different levels of abstraction (superordinate, basic, subordinate) relies on the encoding of relevant diagnostic features present at different spatial scales. We used the Eidolon Factory, an image-manipulation algorithm that introduces random disarray fields across spatial scales, to study how such a process fle...
Article
Full-text available
Faces convey an assortment of emotional information via low and high spatial frequencies (LSFs and HSFs). However, there is no consensus on the role of particular spatial frequency (SF) information during facial fear processing. Comparison across studies is hampered by the high variability in cut-off values for demarcating the SF spectrum and by di...
Preprint
Full-text available
We report a study designed to determine the most efficient means of pursuing sonic seasoning in international marketing. For the first time, music chosen to trigger specific emotional responses was directly and cross-culturally compared with music chosen as crossmodally congruent with specific taste/flavors (the latter usually regarded as ‘sonic se...
Article
Full-text available
Graffiti art is a controversial art form, and as such there has been little empirical work assessing its aesthetic value. A recent study examined image statistical properties of text-based artwork and revealed that images of text contain less global structure relative to fine detail compared to artworks. However, previous research did not include g...
Article
In radiology, 60% to 80% of diagnostic errors are perceptual. The use of more efficient visual search behaviors is expected to reduce these errors. We collected eye-tracking data from participants with different levels of experience when interpreting chest X-rays during the completion of a pathology-detection task. Eye-tracking measures were assess...
Article
Numerous examples of meaningful inter-individual differences in visual processing have been documented in low- and high-level vision. For mid-level vision or perceptual organization, vision scientists have only recently started to study the inter-individual differences structure. In this study, we focus on orientation and proximity as emergent feat...
Article
In his search to create ‘instantaneously capturable’ paintings, Frank Stella started to use Day-Glo alkyd paints as a vehicle to communicate his simple, striped designs. Up till now, art criticism has neglected the visual impact of these fluorescent colours on this concept of ‘instantaneous art’. By presenting participants with Stella’s designs (fl...
Article
Artistic photography is an interesting, but often overlooked, medium within the field of empirical aesthetics. Grounded in an art–science collaboration with art photographer Dominique Genin, this project focused on the relationship between the complexity of a photograph and its aesthetic appeal (beauty, pleasantness, interest). An artistic series o...
Article
Full-text available
Object recognition relies on a hierarchically organized ventral visual stream, with both bottom-up and top-down processes. Here, we aimed at investigating the neural underpinnings of perceptual organization along the ventral visual stream in Autism Spectrum Disorders (ASD), and at determining whether this would be associated with decreased top-down...
Article
Full-text available
Images differ in their memorability in consistent ways across observers. What makes an image memorable is not fully understood to date. Most of the current insight is in terms of high-level semantic aspects, related to the content. However, research still shows consistent differences within semantic categories, suggesting a role for factors at othe...
Article
Full-text available
Visual perception in individuals with autism spectrum disorder (ASD) is often debated in terms of enhanced local and impaired global perception. Deficits in global motion perception seem to support this characterization, although the evidence is inconsistent. We conducted a large meta-analysis on global motion, combining 48 articles on biological a...
Article
Full-text available
Aim: To investigate the underlying factor structure of the 46-item Flemish cerebral visual impairment (CVI) questionnaire, differentiate the factor scores of children with and without CVI, and examine the impact of comorbidities on factor scores. Method: The records of 630 children (386 males, 244 females; median age 77mo; interquartile range 63...
Article
The challenges raised in this article are not with information theory per se, but the assumptions surrounding it. Neuroscience isn't sufficiently critical about the appropriate ‘receiver’ or ‘channel’, focuses on decoding ‘parts’, and often relies on a flawed ‘veridicality’ assumption. If these problematic assumptions were questioned, information t...
Article
Observers can search for a target stimulus at a particular speed and accuracy. Adding an identical context to each stimulus can improve performance when the resulting stimuli form clearly discriminable configurations. This search advantage is known as the configural superiority effect (CSE). A recent study showed that embedding these stimuli in noi...
Article
Full-text available
Why do people like images of neatly organized compositions, collected on blogs like Things Organized Neatly? (http://thingsorganizedneatly.tumblr.com/) We explored which factors might contribute to aesthetic preferences for these images of a set of objects, or parts of objects, organized in a neatly or tidy way, focusing on both stimulus and person...
Article
Full-text available
We investigated task-set control processes and chunking in 16 novices and 16 amateur musicians, who produced unimanual rhythms in three experimental conditions: low-level timing tasks required isochronous tapping at constant target durations; sequencing tasks consisted of individual rhythmic patterns comprising multiple target durations; the task-s...
Article
Full-text available
Behavioral and electroencephalography (EEG) data were analyzed from 30 participants performing a demanding, attention-capturing task in which they had to detect an occasional decrement of luminance of small discs. Crucially, numerous white segments in the background were presented either in random orientations or configuring a contour shape of a sq...
Poster
Full-text available
Previous studies showed that multisensory information is more likely to be attended than unisensory information. These studies typically show that brief auditory stimuli affect detection of visual stimuli. However, it is unclear whether multisensory stimuli affect attention when auditory and visual information are integrated based on temporal synch...
Poster
Full-text available
In this study, we revisited the relation between aesthetics and memorability, for the first time controlling for semantic category. The focus is thereby on the “how” of depicting (i.e., a beautiful image of a subject), rather than on the “what” (i.e., an image of a beautiful subject). We preselected 400 candidate image pairs, matched on semantic ca...
Article
Perceptual-cognitive skills enable an individual to integrate environmental information with existing knowledge to be able to process stimuli and execute appropriate responses on complex tasks. Various underlying processes could explain how perceptual-cognitive skills impact on expert performance, as articulated in three theoretical accounts: (a) t...