Kevin R Brooks
Macquarie University, Department of Psychology, Faculty Member
- Unmatched (da Vinci) Stereopsis, Stereomotion, Motion in depth, Stereophotography, Psychophysics Toolbox, Psychophysics of vision, and 19 morePsychophysics, Binocular vision, Stereoscopic film, Stereoscopic 3-D, 3D display & stereopsis, Stereopsis, Stereoscopy, Face recognition (Psychology), Face Recognition, Face perception, Depth Perception, Motion perception, Visual perception, Perception, Stereo Vision (Computer Vision), Visual perception (Psychology), Human Factors in Visual Perception, Psychology of Visual Perception, and Perception of Self-Motionedit
- My interest in Perception was stimulated early in life by various visual illusions, and by the discovery that my colo... moreMy interest in Perception was stimulated early in life by various visual illusions, and by the discovery that my colour vision was defective. As an undergraduate, I studied Physics at Imperial College, London (UK), before moving to the University of York (UK) to study Psychology. At the University of Sussex (UK) I completed my doctoral thesis, entitled "Mechanisms of Suprathreshold Stereomotion Perception" under the supervision of Professor George Mather. Following my formal education, I continued my research into the perception of motion in depth as Senior Research Associate at NASA Ames Research Center, Moffett Field, (USA) with Dr. Leland Stone. At the University of New South Wales (Australia), a post-doc with Professor Barbara Gillam allowed me to broaden my interest in depth perception to include issues of unmatched stereopsis. A further post-doctoral appointment to work with Dr. Richard Kemp allowed me to develop a long standing interest in face perception. After a Senior Lectureship at the University of Plymouth (UK), I returned to Australia to my current position.edit
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Research Interests:
Research Interests:
Body image disturbance – a cause of distress amongst the general population and those diagnosed with various disorders – is often attributed to the media’s unrealistic depiction of ideal bodies. These ideals are strongly gendered, leading... more
Body image disturbance – a cause of distress amongst the general population and those diagnosed with various disorders – is often attributed to the media’s unrealistic depiction of ideal bodies. These ideals are strongly gendered, leading to pronounced fat concern amongst females, and a male preoccupation with muscularity. Recent research suggests that visual aftereffects may be fundamental to the misperception of body fat and muscle mass – the perceptual component of body image disturbance. This study sought to establish the influence of gender on these body aftereffects. Male and female observers were randomly assigned to one of four adaptation conditions (low fat, high fat, low muscle, and high muscle bodies) and were asked to adjust the apparent fat and muscle levels of male and female bodies to make them appear as ‘normal’ as possible both before and after adaptation. While neither the gender of observers or of body stimuli had a direct effect, aftereffect magnitude was signifi...
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Research has previously shown that adding consistent stereoscopic information to self-motion displays can improve the vection in depth induced in physically stationary observers. In some past studies, the simulated eye-separation was... more
Research has previously shown that adding consistent stereoscopic information to self-motion displays can improve the vection in depth induced in physically stationary observers. In some past studies, the simulated eye-separation was always close to the observer's actual eye-separation, as the aim was to examine vection under ecological viewing conditions that provided consistent binocular and monocular self-motion information. The present study investigated whether large discrepancies between the observer's simulated and physical eye-separations would alter the vection-inducing potential of stereoscopic optic flow (either helping, hindering, or preventing the induction of vection). Our self-motion displays simulated eye-separations of 0 cm (the non-stereoscopic control), 3.25 cm (reduced from normal), 6.5 cm (approximately normal), and 13 cm (exaggerated relative to normal). The rated strength of vection in depth was found to increase systematically with the simulated eye-s...
Research Interests:
Research Interests: Psychology, Cognitive Science, Psychophysics, Perception, Psychophysics of vision, and 15 moreVisual perception, Binocular vision, Motion perception, Stereopsis, Trajectory, Humans, Depth Perception, Female, Male, Adult, Motion in depth, Stereomotion, Motion Aftereffect, Monocular Vision, and Random Allocation
Laboratory-based studies of perceived speed show that, under most circumstances, perceived speed is reduced as a function of contrast. However, a recent investigation of perceived vehicular speed while driving around a closed road circuit... more
Laboratory-based studies of perceived speed show that, under most circumstances, perceived speed is reduced as a function of contrast. However, a recent investigation of perceived vehicular speed while driving around a closed road circuit showed no such effect (Owens, Wood, & Carberry, 2010, Perception, 39: , 1199-1215). We sought to probe the source of this discrepancy, asking whether the presence or absence of stereoscopic motion information might account for the difference in results. In a two-alternative forced-choice psychophysical speed-discrimination task, observers compared the speed of high- and low-contrast driving clips filmed with a 3-D camera and presented either stereoscopically (3-D) or monoscopically (2-D). Although perceived speed was reduced at low contrast, the size of this misperception was equivalent for 2-D and 3-D presentations. However, the inclusion of stereoscopic cues to vehicular speed caused significant improvements in the precision of speed judgments. It is concluded that although stereopsis can provide access to valuable information on perceived speed, contrast-independent speed estimation as demonstrated by Owens et al. (2010) is more likely to reflect the use of the full visual field in a real driving situation (compared with limited field of view simulations), or the additional contributions of nonvisual cues rather than stereopsis.
Research Interests: Psychology, Cognitive Science, Perception, Visual perception, Motion perception, and 15 moreHuman Factors in Visual Perception, Humans, Depth Perception, Female, Male, Young Adult, Driving Simulation, Vection, Adult, Graphic Driving Simulator, Speed Perception, Driving Simulators, Egomotion, Automobile driving, and Psychomotor Performance
Stereomotion (binocularly specified motion-in-depth) studies have established the existence of several cues to speed. For binocular features, cues involve (a) changes in disparity over time ('changing disparity', CD), or (b)... more
Stereomotion (binocularly specified motion-in-depth) studies have established the existence of several cues to speed. For binocular features, cues involve (a) changes in disparity over time ('changing disparity', CD), or (b) differences in the velocities of features between the eyes ('interocular velocity difference', IOVD). Although the precision of these has been studied, their accuracy has not. We performed a 2AFC stereomotion speed discrimination experiment (N= 4) to ascertain the relative perceived speed of RDS (CD and IOVD cues) ...
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The history of the expression of three-dimensional structure in art can be traced from the use of occlusion in Palaeolithic cave paintings, through the use of shadow in classical art, to the development of perspective during the... more
The history of the expression of three-dimensional structure in art can be traced from the use of occlusion in Palaeolithic cave paintings, through the use of shadow in classical art, to the development of perspective during the Renaissance. However, the history of the use of stereoscopic techniques is controversial. Although the first undisputed stereoscopic images were presented by Wheatstone in 1838, it has been claimed that two sketches by Jacopo Chimenti da Empoli (c. 1600) can be to be fused to yield an impression of stereoscopic depth, while others suggest that Leonardo da Vinci's Mona Lisa is the world's first stereogram. Here, we report the first quantitative study of perceived depth in these works, in addition to more recent works by Salvador Dalí. To control for the contribution of monocular depth cues, ratings of the magnitude and coherence of depth were recorded for both stereoscopic and pseudoscopic presentations, with a genuine contribution of stereoscopic cues revealed by a difference between these scores. Although effects were clear for Wheatstone and Dalí's images, no such effects could be found for works produced earlier. As such, we have no evidence to reject the conventional view that the first producer of stereoscopic imagery was Sir Charles Wheatstone.
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Prolonged exposure to images of narrow bodies has been shown to induce a perceptual 18 aftereffect, such that observers’ point of subjective normality (PSN) for bodies shifts towards 19 narrower bodies. The converse effect is shown for... more
Prolonged exposure to images of narrow bodies has been shown to induce a perceptual
18 aftereffect, such that observers’ point of subjective normality (PSN) for bodies shifts towards
19 narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level
20 stimuli, object attention (attention directed to the object) and spatial attention (attention
21 directed to the location of the object) have been shown to increase the magnitude of visual
22 aftereffects, while object-based attention enhances the adaptation effect in faces. It is not
23 known whether featural attention (attention directed to a specific aspect of the object) affects
24 the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of
25 Caucasian observers to different featural information in body images, by asking them to rate
26 the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner
27 than average. PSNs for body fatness were taken at baseline and after adaptation, and a change
28 in PSN (ΔPSN) was calculated. A body size adaptation effect was found, with observers who
29 viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a
30 reduced PSN. However, manipulations of featural attention to body fatness or sex typicality
31 produced equivalent results, suggesting that featural attention may not affect the strength of
32 the body size aftereffect.
18 aftereffect, such that observers’ point of subjective normality (PSN) for bodies shifts towards
19 narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level
20 stimuli, object attention (attention directed to the object) and spatial attention (attention
21 directed to the location of the object) have been shown to increase the magnitude of visual
22 aftereffects, while object-based attention enhances the adaptation effect in faces. It is not
23 known whether featural attention (attention directed to a specific aspect of the object) affects
24 the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of
25 Caucasian observers to different featural information in body images, by asking them to rate
26 the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner
27 than average. PSNs for body fatness were taken at baseline and after adaptation, and a change
28 in PSN (ΔPSN) was calculated. A body size adaptation effect was found, with observers who
29 viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a
30 reduced PSN. However, manipulations of featural attention to body fatness or sex typicality
31 produced equivalent results, suggesting that featural attention may not affect the strength of
32 the body size aftereffect.
Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the " ideal " images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown.... more
Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the " ideal " images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass – variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear " normal " before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia). Body size misperception is a phenomenon wherein people believe themselves or others to be larger or smaller than they actually are 1–3. In research conducted in a broad range of populations, and in both adolescents and adults, as many as half of participants have been found to misperceive their body weight 4–8. This is concerning in two respects 3. First, individuals who are underweight or normal-weight according to accepted classifications but who believe themselves to be overweight are likely to have high levels of body dissatisfaction and, in turn, increased risk of mental health problems such as eating disorders, anxiety and depression 9–11. Further, a recent study involving a multisensory illusion induced using a virtual reality setup has shown a causal link between changes in perceived body size and changes in body dissatisfaction 12. Conversely, individuals who are overweight or obese but who believe themselves to be of normal or otherwise acceptable weight may be less motivated to make efforts to reduce body weight, and less likely to seek help for obesity-related medical problems 6,8,13. To date, research addressing body size misperception has tended to focus on socio-cognitive processes, such as internalization of the " ideal " images of male and female bodies portrayed in the popular media 7,14,15 or, in the case of underestimation of body size among overweight individuals, increased exposure to obesity in everyday life and a consequent change in what is considered a " normal and healthy " body weight 3,8,16. As a consequence, little is known about the perceptual mechanisms underpinning body size misperception. However, there is growing
Research Interests: Psychophysics, Perception, Psychophysics of vision, Human Perception and Performance, Eating Disorders, and 19 moreVisual perception, Adaptation, Body Image, Eating Disorders and Body Image, Muscle Dysmorphia, Body Image (Psychology), Eating Disorders and Obesity, Male body image, Body dysmorphic disorder, Adaptation Aftereffects, Aftereffect, Psychology of Visual Perception, Mass media and body image, Mass Media and the Effects on Body Image, Visual Psychophysics, Body Image Satisfaction, Male Eating Disorders, Body Dysmorphia, and Muscle Dysmorphia An Underrecognized Form of Body Dysmorphic Disorde
The perception of speed is susceptible to manipulations of image contrast, both for simple sine wave and more complex stimuli, such that low-contrast patterns generally appear slower than their high-contrast equivalents. It is not known... more
The perception of speed is susceptible to manipulations of image contrast, both for simple sine wave and more complex stimuli, such that low-contrast patterns generally appear slower than their high-contrast equivalents. It is not known whether the crucial factor is the contrast of the underlying Fourier components or the contrast of the overall complex pattern. Here, two experiments investigate this issue using compound gratings, comprising two vertical sine wave stimuli with equal contrast, but a 3:1 spatial frequency ratio. Component gratings were summed in ''peaks add'' and in ''peaks subtract'' phase, creating conditions with either (a) identical component contrasts, despite differences in overall pattern contrast or (b) differences in component contrasts despite identical overall pattern contrast. Experiment 1 demonstrated that the perceived speed is determined by the contrast of the components regardless of relative phase and hence of overall pattern contrast. Experiment 2 replicated this result while eliminating potential explanations based on differences in spatial frequency content. Along with previous compound grating and plaid studies, the data support a two-stage velocity estimation process involving the derivation of separate speed signals for each Fourier component, followed by integration of these signals across spatial scales. Creative Commons CC-BY: This article is distributed under the terms of the Creative Commons Attribution 3.0 License (http://www.creativecommons.org/licenses/by/3.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sage-pub.com/en-us/nam/open-access-at-sage).
Research Interests:
Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers' point of subjective normality (PSN) for bodies shifts toward narrower bodies. The converse effect is shown for... more
Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers' point of subjective normality (PSN) for bodies shifts toward narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object) and spatial attention (attention directed to the location of the object) have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object) affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (PSN) was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.
Research Interests: Psychophysics, Psychophysics of vision, Visual attention, Visual perception, Attention (Psychology), and 8 moreBody Image, Eating Disorders and Body Image, Visual Attention (Psychology), Body Image (Psychology), Adaptation Aftereffects, Media and Body Image, Visual Psychophysics, and Body Image Satisfaction
Counter-terrorism and crime prevention often depend on our ability to match images of unfamiliar faces. For example, when issuing passports, staff must establish an applicant's identity by comparing the submitted photograph witht those in... more
Counter-terrorism and crime prevention often depend on our ability to match images of unfamiliar faces. For example, when issuing passports, staff must establish an applicant's identity by comparing the submitted photograph witht those in the database of current passports to ensure that multiple documents are not issued to the same person under different names. Previous research has shown that this is a difficult and error prone task. We suggest that this 'passport problem' may be due to an over-reliance on the appearance of external facial features that can be unreliable cues to identity. Compatible with this explanation, we demonstrate that in difficult trials involving a change of appearance or attempted fraud involving a similar looking foil, participants are better able to determine whether two images are of the same person when shown only the internal features of the faces rather than whole images. This discovery has significant practical implications and could form the basis of a procedure to improve the detection of identity fraud.
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PURPOSE. A clinical diagnosis of stereoblindness does not necessarily preclude compelling depth perception. Qualitative observations suggest that this may be due to the dynamic nature of the stimuli. The purpose of this study was to... more
PURPOSE. A clinical diagnosis of stereoblindness does not necessarily preclude compelling depth perception. Qualitative observations suggest that this may be due to the dynamic nature of the stimuli. The purpose of this study was to systematically investigate the effectiveness of static and dynamic stereoscopic stimuli. METHODS. Stereoscopic stimuli were presented on a passive polarized stereoscopic monitor and were manipulated as follows: static disparity (baseline condition), dynamic disparity (change in z-location), change in stimulus pattern, change in z-location with pattern change, change in x-location (horizontal shift), a control (nil-disparity signal). All depth-detection thresholds were measured simultaneously using an adaptive four-alternative-forced-choice (4AFC) paradigm with all six conditions randomly interleaved. RESULTS. A total of 127 participants (85 women, 42 men; mean [SD] age, 21 [5] years) with visual acuity better than 0.22 logMAR in both eyes were assessed. In comparison to the static disparity condition, depth-detection thresholds were up to 50% lower for the dynamic disparity conditions, with and without pattern change (P < 0.001). The presence of a changing pattern in isolation (P ¼ 0.71) or a horizontal shift (P ¼ 0.41) did not affect the thresholds. CONCLUSIONS. Dynamic disparity information facilitates the extraction of depth in comparison to static disparity signals. This finding may account for the compelling perception of depth reported in individuals with no measurable static stereoacuity. Our findings challenge the traditional definition of stereoblindness and suggest that current diagnostic tests using static stimuli may be suboptimal. We argue that both static and dynamic stimuli should be employed to fully assess the binocular potential of patients when considering management options.
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Body size misperception is common amongst the general public and is a core component of eating disorders and related conditions. While perennial media exposure to the " thin ideal " has been blamed for this misperception, relatively... more
Body size misperception is common amongst the general public and is a core component of eating disorders and related conditions. While perennial media exposure to the " thin ideal " has been blamed for this misperception, relatively little research has examined visual adaptation as a potential mechanism. We examined the extent to which the bodies of "self" and "other" are processed by common or separate mechanisms in young women. Using a contingent adaptation paradigm, experiment 1 gave participants prolonged exposure to images both of the self and of another female that had been distorted in opposite directions (e.g., expanded other/contracted self), and assessed the aftereffects using test images both of the self and other. The directions of the resulting perceptual biases were contingent on the test stimulus, establishing at least some separation between the mechanisms encoding these body types. Experiment 2 used a cross adaptation paradigm to further investigate the extent to which these mechanisms are independent. Participants were adapted either to expanded or to contracted images of their own body or that of another female. While adaptation effects were largest when adapting and testing with the same body type, confirming the separation of mechanisms reported in experiment 1, substantial misperceptions were also demonstrated for cross adaptation conditions, demonstrating a degree of overlap in the encoding of self and other. In addition, the evidence of misperception of one's own body following exposure to " thin " and to " fat " others demonstrates the viability of visual adaptation as a model of body image disturbance both for those who underestimate and those who overestimate their own size.
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The dominant evolutionary theory of physical attraction posits that attractiveness reflects physiological health, and attraction is a mechanism for identifying a healthy mate. Previous studies have found that perceptions of the healthiest... more
The dominant evolutionary theory of physical attraction posits that attractiveness reflects physiological health, and attraction is a mechanism for identifying a healthy mate. Previous studies have found that perceptions of the healthiest body mass index (weight scaled for height; BMI) for women are close to healthy BMI guidelines, while the most attractive BMI is significantly lower, possibly pointing to an influence of sociocultural factors in determining attractive BMI. However, less is known about ideal body size for men. Further, research has not addressed the role of body fat and muscle, which have distinct relationships with health and are conflated in BMI, in determining perceived health and attractiveness. Here, we hypothesised that, if attractiveness reflects physiological health, the most attractive and healthy appearing body composition should be in line with physiologically healthy body composition. Thirty female and 33 male observers were instructed to manipulate 15 female and 15 male body images in terms of their fat and muscle to optimise perceived health and, separately, attractiveness. Observers were unaware that they were manipulating the muscle and fat content of bodies. The most attractive apparent fat mass for female bodies was significantly lower than the healthiest appearing fat mass (and was lower than the physiologically healthy range), with no significant difference for muscle mass. The optimal fat and muscle mass for men's bodies was in line with the healthy range. Male observers preferred a significantly lower overall male body mass than did female observers. While the body fat and muscle associated with healthy and attractive appearance is broadly in line with physiologically healthy values, deviations from this pattern suggest that future research should examine a possible role for internalization of body ideals in influencing perceptions of attractive body composition, particularly in women.
Research Interests: Evolutionary Psychology, Body Image, Health, Male body image, Drive for Muscularity and Body Dissatisfaction Among Athletes and Non Athletes, and 8 morePercentage of body fat (PBF), Drive for Muscularity, Body Image, Body Fat, Physical Attractiveness, Muscularity-oriented Disordered Eating, Body Image Between Males and Females, Body fat percentage, and Muscularity
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Research Interests: Psychology, Cognitive Science, Psychophysics, Perception, Photography, and 13 morePsychophysics of vision, Visual perception, Face recognition (Psychology), Adolescent, Visual perception (Psychology), Humans, Body perception, Form perception, Female, Young Adult, Waist to Hip Ratio, Adult, and Body Shape
Research Interests: Bioinformatics, Computer Vision, Visual perception, Computational Neuroscience, Life Sciences, and 16 moreMachine Vision, Model, Biomedical Research, Illusions, Illusion, Cortex, Optical Illusions, Visual, Muller-Lyer illusion, Computational, Clinical Sciences, Computational Cognitive Neuroscience, Computational neurosciences, Computational/ Interdisciplinary Neuroscience, HMAX Model, and Neurosciences
Abstract To examine the spatial scale of the mechanism supporting the perception of motion-in-depth defined by binocular disparity cues, we measured stereomotion speed discrimination thresholds as a function of stimulus width using a 2IFC... more
Abstract To examine the spatial scale of the mechanism supporting the perception of motion-in-depth defined by binocular disparity cues, we measured stereomotion speed discrimination thresholds as a function of stimulus width using a 2IFC paradigm. Dynamic random dot stereogram bars, wherein new but perfectly binocularly correlated dot arrays are presented interleaved at a rate of 120Hz per eye, were displayed using ferro-electric shutter glasses on a 240Hz fast-phosphor monitor. Frame-by-frame manipulation of disparity ...
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Abstract Slanted surfaces are often seen against backgrounds or through apertures. In addition to providing a binocular context, such conditions result in the presence of monocular regions (sidebands) at the side of the binocularly... more
Abstract Slanted surfaces are often seen against backgrounds or through apertures. In addition to providing a binocular context, such conditions result in the presence of monocular regions (sidebands) at the side of the binocularly slanted surface whose locations and/or relative widths could provide information about slant independent of azimuth, distance to the slanted surface, distance between surface and background/aperture or width of the slanted surface. Sidebands can be either temporal on each eye ( ...
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Abstract Stereomotion experiments often feature monocularly visible stimuli. When such stimuli move in depth, different monocular motion signals are presented simultaneously to each eye. Though this &amp;amp;#x27;inter-ocular velocity... more
Abstract Stereomotion experiments often feature monocularly visible stimuli. When such stimuli move in depth, different monocular motion signals are presented simultaneously to each eye. Though this &amp;amp;#x27;inter-ocular velocity difference&amp;amp;#x27;cue to stereomotion has been investigated in a number of studies, the observed behaviour could theoretically have been based on properties of an individual monocular image. To isolate such potential artifacts, we performed a 2IFC speed-discrimination task using random dot stereograms moving either ...
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Abstract Howard and Duke (Vision Research, 2003) generated binocular displays that contained a grey transparent square offset from a vertical bar in one eye, and a vertical bar with a gap in the other eye. Observers perceived a... more
Abstract Howard and Duke (Vision Research, 2003) generated binocular displays that contained a grey transparent square offset from a vertical bar in one eye, and a vertical bar with a gap in the other eye. Observers perceived a transparent square in depth that gave rise to quantitative percepts of depth. The authors argued these displays constituted a new form of stereopsis, since they were “without conventional disparity” and that the depth experienced was due to “transparency rather than occlusion”. Although there were no ...
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Two binocular cues to motion in depth have been identified psychophysically: change of disparity (CD) and interocular velocity difference (IOVD). We evince a third stereomotion cue arising from changes in the extent of binocularly... more
Two binocular cues to motion in depth have been identified psychophysically: change of disparity (CD) and interocular velocity difference (IOVD). We evince a third stereomotion cue arising from changes in the extent of binocularly unpaired regions. In experiment 1, a solid black rectangle was presented to one eye, the other eye viewing two rectangles (each half the width of the larger one), separated by a central vertical gap (unpaired background stereopsis: Gillam et al, 1999 Vision Research 39 493-502). As these rectangles were ...
Motion in depth; MID; Speed perception Psychology Psychology.
Description As we move around the world, complex patterns of visual motion are produced that can in principle be informative about self-motion, or the motion of objects in our visual field. These fields of motion vectors, referred to as... more
Description As we move around the world, complex patterns of visual motion are produced that can in principle be informative about self-motion, or the motion of objects in our visual field. These fields of motion vectors, referred to as optic flow patterns, can be decomposed into four independent first order differential invariants, namely divergence ('div': related to expansion or contraction), curl (related to clockwise or anticlockwise rotation), and 2 components of deformation ('def': dilation and pure shear). Here, experiments are reported ...
Macquarie University ResearchOnline.
Description Variations of perceived speed with spatial frequency (SF), temporal frequency (TF), and contrast have been known for many years. However, these effects have largely been studied in isolation, preventing comparison of the... more
Description Variations of perceived speed with spatial frequency (SF), temporal frequency (TF), and contrast have been known for many years. However, these effects have largely been studied in isolation, preventing comparison of the perceived speed of stimuli across the spatio-temporal frequency surface. We present the first systematic study to establish the perceived speed of high and low contrast (70% and 7%) stimuli across a broad range of Fourier parameters (SFs from 0.25-8c/deg; TFs from 2-16Hz; speeds from 0.25-64deg/s). ...
Macquarie University ResearchOnline.
Description Recent studies have shown that facial images created by‗ morphing 'faces from two different races are generally rated as being more attractive than single-race component faces. It has been suggested that the morphology of... more
Description Recent studies have shown that facial images created by‗ morphing 'faces from two different races are generally rated as being more attractive than single-race component faces. It has been suggested that the morphology of mixed-race faces can be considered a marker for heterozygosity, and hence increased immunocompetence–an attractive trait in mate selection. The current study aimed to examine whether greater racial diversity is associated with greater attractiveness, or whether attractiveness peaks at an optimal level. ...
Description Facial movement may provide cues to identity that can supplement or even supplant static facial information. We investigated whether participants could match dynamic familiar and unfamiliar faces when static cues were... more
Description Facial movement may provide cues to identity that can supplement or even supplant static facial information. We investigated whether participants could match dynamic familiar and unfamiliar faces when static cues were minimised, using facial point-light-displays (PLDs) or shape-averaged avatars. Experiment 1 tested the matching of famous and unfamiliar faces in a same/different task, using the same stimulus type within each pair. Experiment 2 replicated Experiment 1, except that participants attempted to match full-face ...
Although body size and shape misperception (BSSM) is a common feature of anorexia nervosa, bulimia nervosa and muscle dysmorphia, little is known about its underlying neural mechanisms. Recently, a new approach has emerged, based on the... more
Although body size and shape misperception (BSSM) is a common feature of anorexia nervosa, bulimia nervosa and muscle dysmorphia, little is known about its underlying neural mechanisms. Recently, a new approach has emerged, based on the long-established non-invasive technique of perceptual adaptation, which allows for inferences about the structure of the neural apparatus responsible for alterations in visual appearance. Here, we describe several recent experimental examples of BSSM, wherein exposure to " extreme " body stimuli causes visual aftereffects of biased perception. The implications of these studies for our understanding of the neural and cognitive representation of human bodies, along with their implications for clinical practice are discussed. Creative Commons Non Commercial CC-BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (http://www.creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).