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Journal of Comparative Psychology... Nov 2021To date, no studies have examined the ontogeny of susceptibility to visual illusions in nonhuman mammals. Our previous study on the perception of the Delboeuf illusion...
To date, no studies have examined the ontogeny of susceptibility to visual illusions in nonhuman mammals. Our previous study on the perception of the Delboeuf illusion by adult cats suggested they perceive this illusion, and that the visual processing involved in size judgment differs in the presence or absence of a misleading surround. We therefore asked whether weanling kittens are susceptible to the Delboeuf visual illusion, as adult cats are. Like the adults, kittens were presented with a series of 2-way food choice tasks where same- or different-size food portions were presented on same- or different-size plates. In control trials, the kittens significantly discriminated between 2 different amounts of food on same-size plates and, like adults, they chose the larger amount; when the difference between the food amounts was greater, the kittens chose the larger amount more reliably. Olfactory control trials confirmed that kittens, like adults, used visual cues when comparing quantities in this setting. In contrast to adults, however, in the illusion trials with same-size food portions on different-size plates, the kittens did not choose either of the 2 different-size plates significantly above chance and so did not appear to perceive the illusion. This suggests heterochronicity in the development of the cat visual system in which the ability to discriminate sizes develops before susceptibility to an illusion using these stimuli. Remaining questions include at what age susceptibility to visual illusions emerges and whether this depends on continued maturation of the brain, on experience of the visual world, or both. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Topics: Animals; Cats; Cues; Discrimination, Psychological; Felis; Female; Illusions; Visual Perception
PubMed: 34435838
DOI: 10.1037/com0000288 -
Attention, Perception & Psychophysics Feb 2024Visual scenes are too complex for one to immediately perceive all their details. As suggested by Gestalt psychologists, grouping similar scene elements and perceiving...
Visual scenes are too complex for one to immediately perceive all their details. As suggested by Gestalt psychologists, grouping similar scene elements and perceiving their summary statistics provides one shortcut for evaluating scene gist. Perceiving ensemble statistics overcomes processing, attention, and memory limits, facilitating higher-order scene understanding. Ensemble perception spans simple/complex dimensions (circle size, face emotion), including various statistics (mean, range), and inherently spans space and/or time, when sets are presented scattered across the visual scene, and/or sequentially in rapid series. Furthermore, ensemble perception occurs explicitly, when observers are asked to judge set mean, and also automatically/implicitly, when observers are engaged in an orthogonal task. We now study relationships among these ensemble-perception phenomena, testing explicit and implicit ensemble perception; for sets varying in circle size, line orientation, or disc brightness; and with spatial, temporal or spatio-temporal presentation. Following ensemble set presentation, observers were asked if a test image, or which of two test images, had been present in the set. Confirming previous results, responses reflected implicit mean perception, depending on test image distance from the mean, and on its being within or outside ensemble range. Subsequent experiments asked the same observers to explicitly judge whether test images were larger, more clockwise, or brighter than the set mean, or which of two test images was closer to the mean. Comparing implicit and explicit mean perception, we find that explicit ensemble averaging is more precise than implicit mean perception-for each ensemble variable and presentation mode. Implications are discussed regarding possible separate mechanisms for explicit versus implicit ensemble perception.
Topics: Humans; Attention; Emotions; Perception; Visual Perception
PubMed: 37821745
DOI: 10.3758/s13414-023-02784-4 -
Neuropsychologia Jan 2024A stable representation of object size, in spite of continuous variations in retinal input due to changes in viewing distance, is critical for perceiving and acting in a...
A stable representation of object size, in spite of continuous variations in retinal input due to changes in viewing distance, is critical for perceiving and acting in a real 3D world. In fact, our perceptual and visuo-motor systems exhibit size and grip constancies in order to compensate for the natural shrinkage of the retinal image with increased distance. The neural basis of this size-distance scaling remains largely unknown, although multiple lines of evidence suggest that size-constancy operations might take place remarkably early, already at the level of the primary visual cortex. In this study, we examined for the first time the temporal dynamics of size constancy during perception and action by using a combined measurement of event-related potentials (ERPs) and kinematics. Participants were asked to maintain their gaze steadily on a fixation point and perform either a manual estimation or a grasping task towards disks of different sizes placed at different distances. Importantly, the physical size of the target was scaled with distance to yield a constant retinal angle. Meanwhile, we recorded EEG data from 64 scalp electrodes and hand movements with a motion capture system. We focused on the first positive-going visual evoked component peaking at approximately 90 ms after stimulus onset. We found earlier latencies and greater amplitudes in response to bigger than smaller disks of matched retinal size, regardless of the task. In line with the ERP results, manual estimates and peak grip apertures were larger for the bigger targets. We also found task-related differences at later stages of processing from a cluster of central electrodes, whereby the mean amplitude of the P2 component was greater for manual estimation than grasping. Taken together, these findings provide novel evidence that size constancy for real objects at real distances occurs at the earliest cortical stages and that early visual processing does not change as a function of task demands.
Topics: Humans; Distance Perception; Biomechanical Phenomena; Visual Perception; Movement; Electroencephalography; Size Perception
PubMed: 38081353
DOI: 10.1016/j.neuropsychologia.2023.108746 -
Attention, Perception & Psychophysics May 2024Ensemble perception refers to the ability to accurately and rapidly perceive summary statistical representations of specific features from a group of similar objects....
Ensemble perception refers to the ability to accurately and rapidly perceive summary statistical representations of specific features from a group of similar objects. However, the specific type of representation involved in this perception within a three-dimensional (3-D) environment remains unclear. In the context of perspective viewing with stereopsis, distal stimuli can be projected onto the retina as different forms of proximal stimuli based on their distances, despite sharing similar properties, such as object size and spatial frequency. This study aimed to investigate the effects of distal and proximal stimuli on the perception of summary statistical information related to orientation. In our experiment, we presented multiple Gabor patches in a stereoscopic environment, allowing us to measure the discrimination threshold of the mean orientation. The object size and spatial frequency were fixed for all patches regardless of depth. However, the physical angular size and absolute spatial frequency covaried with the depth. The results revealed the threshold elevation with depth expansion, especially when the patches formed two clusters at near and far distances, leading to large variations in their retinotopic representations. This finding indicates a minor contribution of similarity of the distal stimuli. Subsequent experiments demonstrated that the variability in physical angular size of the patches significantly influenced the threshold elevation in contrast to that of binocular disparity and absolute spatial frequency. These findings highlight the critical role of physical angular size variability in perceiving mean orientations within the 3-D space.
Topics: Humans; Depth Perception; Discrimination, Psychological; Male; Female; Adult; Young Adult; Orientation; Pattern Recognition, Visual; Vision Disparity; Size Perception; Space Perception
PubMed: 38514597
DOI: 10.3758/s13414-024-02881-y -
Journal of Experimental Child Psychology Dec 2022Previous work shows that in adults, illusory embodiment of a virtual avatar can be induced using congruent visuomotor cues. Furthermore, embodying different-sized...
Previous work shows that in adults, illusory embodiment of a virtual avatar can be induced using congruent visuomotor cues. Furthermore, embodying different-sized avatars influences adults' perception of their environment's size. This study (N = 92) investigated whether children are also susceptible to such embodiment and size illusions. Adults and 5-year-old children viewed a first-person perspective of different-sized avatars moving either congruently or incongruently with their own body. Participants rated their feelings of embodiment over the avatar and also estimated the sizes of their body and objects in the environment. Unlike adults, children embodied the avatar regardless of visuomotor congruency. Both adults and children freely embodied different-sized avatars, and this affected their size perception in the surrounding virtual environment; they felt that objects were larger in a small body and vice versa in a large body. In addition, children felt that their body had grown in the large body condition. These findings have important implications for both our theoretical understanding of own-body representation, and our knowledge of perception in virtual environments.
Topics: Adult; Body Image; Body Size; Child, Preschool; Humans; Illusions; Size Perception; Virtual Reality
PubMed: 35964343
DOI: 10.1016/j.jecp.2022.105518 -
Frontiers in Psychology 2021Previous studies have shown that our perception of stimulus properties can be affected by the emotional nature of the stimulus. It is not clear, however, how emotions...
Previous studies have shown that our perception of stimulus properties can be affected by the emotional nature of the stimulus. It is not clear, however, how emotions affect visually-guided actions toward objects. To address this question, we used toy rats, toy squirrels, and wooden blocks to induce negative, positive, and neutral emotions, respectively. Participants were asked to report the perceived distance and the perceived size of a target object resting on top of one of the three emotion-inducing objects; or to grasp the same target object either without visual feedback (open-loop) or with visual feedback (closed-loop) of both the target object and their grasping hand during the execution of grasping. We found that the target object was perceived closer and larger, but was grasped with a smaller grip aperture in the rat condition than in the squirrel and the wooden-block conditions when no visual feedback was available. With visual feedback present, this difference in grip aperture disappeared. These results showed that negative emotion influences both perceived size and grip aperture, but in opposite directions (larger perceived size but smaller grip aperture) and its influence on grip aperture could be corrected by visual feedback, which revealed different effects of emotion to perception and action. Our results have implications on the understanding of the relationship between perception and action in emotional condition, which showed the novel difference from previous theories.
PubMed: 34650465
DOI: 10.3389/fpsyg.2021.651885 -
Cureus Jun 2022While the American standard of beauty idolizes unattainable thinness, social media exposure has been instrumental in crafting a more inclusive perception of beauty.
BACKGROUND
While the American standard of beauty idolizes unattainable thinness, social media exposure has been instrumental in crafting a more inclusive perception of beauty.
METHODS
Using several websites with public data on models, we gathered body measurements and characteristics of both plus-size and the overall top 10 paid mainstream models. We then collected social media data for these models using the social media analytics tool called Social Blade. We compared social media data between plus-size and mainstream models.
RESULTS
While plus-size models have increased BMI, the waist/hip ratio was 0.74 on average, compared to 0.71 in mainstream models. The average social media following among the top 10 plus-size models was 3.8 million compared to 38 million amongst the top 10 mainstream models (p = 0.039). There was no significant difference between the average likes per post, average comments per post, and total posts between the top mainstream models and top plus-size models (p-values 0.11, 0.12, and 0.15, respectively).
CONCLUSION
With the changing societal body image in America, plus-size models have gained in popularity and positively impacted a body-inclusive model of beauty. However, the mainstream model still prevails as the social media powerhouse of influence.
PubMed: 35785000
DOI: 10.7759/cureus.25584 -
PloS One 2022Simply inspecting one's own body can reduce clinical pain and magnification of body parts can increase analgesia. Thus, body perceptions seem to play an important role...
INTRODUCTION
Simply inspecting one's own body can reduce clinical pain and magnification of body parts can increase analgesia. Thus, body perceptions seem to play an important role for analgesia. Conversely, pain may also affect bodily perceptions. Therefore, we evaluated the effects of clinical and/or experimental pain on perceived hand size in fibromyalgia patients (FM) and healthy controls (HC).
METHODS
To investigate the effects of chronic and/or acute pain on size perception we compared hand size estimates of 35 HC and 32 FM patients at baseline and during tonic mechanical pain stimuli applied to one ear lobe. Mechanical stimuli were adjusted for each individual pain sensitivity to achieve a rating of 4 ± 1 VAS (0-10) units. Photographs of each subject's hands were digitally manipulated to produce a monotonic series of 5 images larger and 6 smaller than actual size which were then presented to the participants in ascending and descending order (total number of images: 12).
RESULTS
FM and HC participants' clinical pain ratings at baseline were 3.3 (3.1) and .3 (.8) VAS units, respectively. At baseline, FM participants selected significantly smaller hand images than HC as representative of their actual size (p < .02). During application of tonic experimental pain, the image size chosen to represent their actual hand size decreased significantly in FM participants and HC (p < .001) but this decrease was not different between groups (p > .05). Hand size estimates of FM participants correlated negatively with their clinical pain ratings (p < .04).
CONCLUSION
The decreased hand size perception of FM patients and HC was associated with their clinical and/or experimental pain, supporting the hypothesis that pain can result in visual body distortions.
Topics: Analgesia; Fibromyalgia; Humans; Pain; Pain Measurement; Pain Threshold
PubMed: 35877689
DOI: 10.1371/journal.pone.0270701 -
PloS One 2023Birth weight is a consistent predictor of morbidity and survivability in infancy and later life. This study aims to assess the accuracy of the mother's perception of...
Birth weight is a consistent predictor of morbidity and survivability in infancy and later life. This study aims to assess the accuracy of the mother's perception of size at birth to predict low birth weight(LBW). This study used data from Nepal Demographic and Health Survey (NDHS 2016). Information about 5060 mother pairs was obtained from the NDHS dataset. However, birth weight data were available for 3095 children, and therefore they were only included in the further analysis. The predictive accuracy of the mother's perception of size at birth to predict LBW was measured by sensitivity, specificity, positive predictive value, and negative predictive value. Factors associated with the discordance among the mother's perception of birth size and birth weight were calculated using multinomial logistic regression analysis. The mother's perception of birth size had low sensitivity (62%) and positive predictive value (46.7%) but high specificity (90.1%) and negative predictive value (94.4%) to predict the LBW. The overall agreement between birth weight(<2500gram vs > = 2500 grams) and the mother's perceived size at birth (small vs average or above average) was 86% (Kappa = 0.45, 95%CI: 0.40-0.51), which is composed of a higher share of the agreement to identify non-LBW babies(79%) and a low share to identify LBW babies (7%). Among the five categories of mothers' perception of size at birth and birth weight, the agreement was 67.2% (Kappa = 0.29, 95% CI: 0.26-0.33). Education status, ethnicity, multiple births, and sex of the newborn child were significantly associated with the discordance between the mother's perceived size at birth and birth weight. A moderate agreement was found among the mother's perception of birth size and birth weight. Mothers were more likely to correctly identify non-LBW babies compared to LBW babies based on their perception of size at birth. Efforts should be intensified to promote the practice of weighing the baby at birth.
Topics: Infant, Newborn; Pregnancy; Female; Humans; Birth Weight; Nepal; Infant, Low Birth Weight; Perception; Demography
PubMed: 36693063
DOI: 10.1371/journal.pone.0280788 -
Cognitive Research: Principles and... Jul 2022A common problem in video conferences is gaze direction. In face-to-face communication, it is common that speaker and listener intermittently look at each other. In a...
A common problem in video conferences is gaze direction. In face-to-face communication, it is common that speaker and listener intermittently look at each other. In a video-conference setting, where multiple participants are on the screen, things are complicated and not necessarily optimal. If the listener feels looked at when the speaker looks into the camera, how tolerant is the listener for slight deviations? And does this depend on the position of the speaker's tile on the screen, or the size of the tile? In a first experiment, participants from a student population judged whether they are looked at, while vertical gaze direction of the looker was varied. Furthermore, the position of the tile on the screen varied. The results showed that a slightly upward directed gaze was optimal for the direct gaze judgment, with a width of ± 4 degrees. Optimal gaze direction was somewhat higher for tiles at the bottom of the screen. A second experiment tested the effect of size on the perception of horizontal gaze directions. Size was found to increase the gaze cone. The paper concludes with some recommendations for a setup of video conference systems, optimized for perceived gaze contact.
Topics: Communication; Emotions; Humans; Judgment; Perception; Videoconferencing
PubMed: 35867185
DOI: 10.1186/s41235-022-00418-1