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Optics Express Mar 2024Viewers of digital displays often experience motion artifacts (e.g., flicker, judder, edge banding, motion blur, color breakup, depth distortion) when presented with...
Viewers of digital displays often experience motion artifacts (e.g., flicker, judder, edge banding, motion blur, color breakup, depth distortion) when presented with dynamic scenes. We developed an interactive software tool for display designers that predicts how a viewer perceives motion artifacts for a variety of stimulus, display, and viewing parameters: the Binocular Perceived Motion Artifact Predictor (BiPMAP). The tool enables the user to specify numerous stimulus, display, and viewing parameters. It implements a model of human spatiotemporal contrast sensitivity in order to determine which artifacts will be seen by a viewer and which will not. The tool visualizes the perceptual effects of discrete space-time sampling on the display by presenting side by side the expected perception when the stimulus is continuous compared to when the same stimulus is presented with the spatial and temporal parameters of a prototype display.
PubMed: 38571049
DOI: 10.1364/OE.510985 -
Neurological Sciences : Official... Apr 2024Sensorial non-motor symptoms (NMSs) in Parkinson's disease (PD) still lack appropriate investigation in clinical practice. This study aimed to assess if and to what...
BACKGROUND
Sensorial non-motor symptoms (NMSs) in Parkinson's disease (PD) still lack appropriate investigation in clinical practice. This study aimed to assess if and to what extent auditory dysfunction is associated with other NMSs in PD and its impact on patient's quality of life (QoL).
METHODS
We selected patients with idiopathic PD, without other concomitant neurological diseases, dementia, or diagnosis of any audiological/vestibular disease. Demographic and clinical data were collected. Patients underwent otoscopic examination, audiological testing with pure tone audiometry (PTA) and distortion product otoacoustic emissions (DPOAEs) and completed Non-Motor Symptoms Scale (NMSS) and Parkinson's Disease Questionnaires-39 (PDQ-39). ANCOVA and partial correlation analysis have been used for statistical analysis.
RESULTS
60 patients were enrolled and completed PTA and DPOAEs. 32 patients with hearing impairment (HI), assessed by PTA, (hearing threshold ≥ 25 dB) showed similar disease duration, motor impairment, and staging, compared to patients without HI, but higher scores both in NMSS and in PDQ-39, except for cardiovascular (CV), gastrointestinal (GI), urogenital (U) and sexual function (SF) of NMSS. In addition, DPOAEs showed a significant correlation with higher scores both in NMSS and PDQ-39, except for CV, SF, GI, U and perceptual problem subdomains of NMSS.
CONCLUSION
This study demonstrated that PD patients with HI have a greater burden of NMS and lower related QoL and functioning. Our results highlight the importance to reconsider HI as a NMS, in parallel with the others. HI evaluation, even in asymptomatic patients, may reveal a wider pathology with a worse QoL.
PubMed: 38561486
DOI: 10.1007/s10072-024-07487-8 -
Frontiers in Psychology 2024Previous work on audio quality evaluation has demonstrated a developing convergence of the key perceptual attributes underlying judgments of quality, such as timbral,...
INTRODUCTION
Previous work on audio quality evaluation has demonstrated a developing convergence of the key perceptual attributes underlying judgments of quality, such as timbral, spatial and technical attributes. However, across existing research there remains a limited understanding of the crucial perceptual attributes that inform audio quality evaluation for people with hearing loss, and those who use hearing aids. This is especially the case with music, given the unique problems it presents in contrast to human speech.
METHOD
This paper presents a sensory evaluation study utilising descriptive analysis methods, in which a panel of hearing aid users collaborated, through consensus, to identify the most important perceptual attributes of music audio quality and developed a series of rating scales for future listening tests. Participants ( = 12), with a hearing loss ranging from mild to severe, first completed an online elicitation task, providing single-word terms to describe the audio quality of original and processed music samples; this was completed twice by each participant, once with hearing aids, and once without. Participants were then guided in discussing these raw terms across three focus groups, in which they reduced the term space, identified important perceptual groupings of terms, and developed perceptual attributes from these groups (including rating scales and definitions for each).
RESULTS
Findings show that there were seven key perceptual dimensions underlying music audio quality (, , , , , , and ), alongside a music audio quality attribute and possible alternative frequency balance attributes.
DISCUSSION
We outline how these perceptual attributes align with extant literature, how attribute rating instruments might be used in future work, and the importance of better understanding the music listening difficulties of people with varied profiles of hearing loss.
PubMed: 38449751
DOI: 10.3389/fpsyg.2024.1310176 -
Optics Express Feb 2024Improving images captured under low-light conditions has become an important topic in computational color imaging, as it has a wide range of applications. Most current...
Improving images captured under low-light conditions has become an important topic in computational color imaging, as it has a wide range of applications. Most current methods are either based on handcrafted features or on end-to-end training of deep neural networks that mostly focus on minimizing some distortion metric -such as PSNR or SSIM- on a set of training images. However, the minimization of distortion metrics does not mean that the results are optimal in terms of perception (i.e. perceptual quality). As an example, the perception-distortion trade-off states that, close to the optimal results, improving distortion results in worsening perception. This means that current low-light image enhancement methods -that focus on distortion minimization- cannot be optimal in the sense of obtaining a good image in terms of perception errors. In this paper, we propose a post-processing approach in which, given the original low-light image and the result of a specific method, we are able to obtain a result that resembles as much as possible that of the original method, but, at the same time, giving an improvement in the perception of the final image. More in detail, our method follows the hypothesis that in order to minimally modify the perception of an input image, any modification should be a combination of a local change in the shading across a scene and a global change in illumination color. We demonstrate the ability of our method quantitatively using perceptual blind image metrics such as BRISQUE, NIQE, or UNIQUE, and through user preference tests.
PubMed: 38439250
DOI: 10.1364/OE.509713 -
IEEE Transactions on Visualization and... May 2024We provide the first perceptual quantification of user's sensitivity to radial optic flow artifacts and demonstrate a promising approach for masking this optic flow...
We provide the first perceptual quantification of user's sensitivity to radial optic flow artifacts and demonstrate a promising approach for masking this optic flow artifact via blink suppression. Near-eye HMOs allow users to feel immersed in virtual environments by providing visual cues, like motion parallax and stereoscopy, that mimic how we view the physical world. However, these systems exhibit a variety of perceptual artifacts that can limit their usability and the user's sense of presence in VR. One well-known artifact is the vergence-accommodation conflict (VAC). Varifocal displays can mitigate VAC, but bring with them other artifacts such as a change in virtual image size (radial optic flow) when the focal plane changes. We conducted a set of psychophysical studies to measure users' ability to perceive this radial flow artifact before, during, and after self-initiated blinks. Our results showed that visual sensitivity was reduced by a factor of 10 at the start and for ~70 ms after a blink was detected. Pre- and post-blink sensitivity was, on average, ~O.15% image size change during normal viewing and increased to ~1.5- 2.0% during blinks. Our results imply that a rapid (under 70 ms) radial optic flow distortion can go unnoticed during a blink. Furthermore, our results provide empirical data that can be used to inform engineering requirements for both hardware design and software-based graphical correction algorithms for future varifocal near-eye displays. Our project website is available at https://gamma.umd.edu/ROF/.
Topics: Optic Flow; Computer Graphics; Accommodation, Ocular; Algorithms; Software
PubMed: 38437086
DOI: 10.1109/TVCG.2024.3372075 -
Sleep Medicine Apr 2024Decreased sleep spindle activity in individuals with psychotic disorders is well studied, but its contribution to psychotic symptom formation is not well understood....
Decreased sleep spindle activity in individuals with psychotic disorders is well studied, but its contribution to psychotic symptom formation is not well understood. This study explored potential underlying mechanisms explaining the association between decreased sleep spindle activity and psychotic symptoms. To this end, we analysed the links between sleep spindle activity and psychotic experiences and probed for the mediating roles of attentional performance and perceptual distortions in a community sample of young adults (N = 70; 26.33 ± 4.84 years). Polysomnography was recorded during a 90-min daytime nap and duration, amplitude, and density from slow (10-13 Hz) and fast (13-16 Hz) spindles were extracted. Attentional performance was assessed via a test battery and with an antisaccadic eye movement task. Psychotic experiences (i.e., paranoid thoughts; hallucinatory experiences) and perceptual distortions (i.e., anomalous perceptions; sensory gating deficits) were assessed via self-report questionnaires. We conducted sequential mediation analyses with spindle activity as predictor, psychotic experiences as dependent variable, and attentional performance and perceptual distortions as mediators. We found reduced right central spindle amplitude to be associated with paranoid thoughts. Increased antisaccadic error rate was associated with anomalous perceptions and perceptual distortions were associated with psychotic experiences. We did not find significant mediation effects. The findings support the notion that reduced sleep spindle activity is involved in the formation of paranoid thoughts and that decreased antisaccadic performance is indicative of perceptual distortions as potential precursors for psychotic experiences. However, further research is needed to corroborate the proposed mediation hypothesis.
Topics: Young Adult; Humans; Perceptual Distortion; Sleep; Polysomnography; Psychotic Disorders; Attention; Electroencephalography
PubMed: 38422784
DOI: 10.1016/j.sleep.2024.02.023 -
The Annals of Otology, Rhinology, and... May 2024Chronic rhinosinusitis and related rhinologic disorders are common in routine otolaryngologic practice. Common presenting symptoms include nasal obstruction, facial...
OBJECTIVES
Chronic rhinosinusitis and related rhinologic disorders are common in routine otolaryngologic practice. Common presenting symptoms include nasal obstruction, facial pain, facial pressure, headache, and a subjective feeling of the face feeling "swollen," a perceptual distortion. No validated scale exists to assess facial pain in addition to perceptual distortion or headache. The objective was to develop a novel scale for assessment of facial symptoms experienced by patients presenting for rhinologic evaluation.
METHODS
This was a prospective validation cross-sectional study. A patient questionnaire, the 12-item Facial Complaints Evaluation Scale (FaCES-12), was created to evaluate facial symptoms based on clinical experience and the literature, including severity and timing of facial pain, facial pressure, facial perceptual swelling, and headache. Each item was assessed utilizing an 11-point Likert scale ranging from 0 to 10 in severity. Data was collected prospectively from 210 patients in 1 private and 2 academic otolaryngologic practices from August to December 2019 along with the PROMIS Pain Intensity Scale 3a and 22-Item Sino-nasal Outcome Test. Construct validity was determined using Pearson correlation and exploratory factor analysis. Internal consistency and test-retest reliability were assessed by calculating Cronbach's alpha and assessing test-retest scores.
RESULTS
A new 12-item scale named FaCES-12 was developed. FaCES-12 demonstrated high reliability with a Cronbach's alpha of .94 and high test-retest reliability ( = .90). The scale revealed very strong correlation with the PROMIS Pain Intensity Scale 3a ( = .81) and moderate correlation with the Sino-nasal Outcome Test ( = .48). Exploratory factor analysis demonstrated the scale contained interrelated variables that measured unique components of facial sensations.
CONCLUSION
The FaCES-12 is a valid and reliable instrument for use in the evaluation of facial symptoms. Further research into the application of this scale is warranted.
Topics: Humans; Reproducibility of Results; Cross-Sectional Studies; Sinusitis; Headache; Facial Pain; Surveys and Questionnaires; Psychometrics
PubMed: 38380629
DOI: 10.1177/00034894241233034 -
Scientific Reports Feb 2024The eye's natural aging influences our ability to focus on close objects. Without optical correction, all adults will suffer from blurry close vision starting in their...
The eye's natural aging influences our ability to focus on close objects. Without optical correction, all adults will suffer from blurry close vision starting in their 40s. In effect, different optical corrections are necessary for near and far vision. Current state-of-the-art glasses offer a gradual change of correction across the field of view for any distance-using Progressive Addition Lenses (PALs). However, an inevitable side effect of PALs is geometric distortion, which causes the swim effect, a phenomenon of unstable perception of the environment leading to discomfort for many wearers. Unfortunately, little is known about the relationship between lens distortions and their perceptual effects, that is, between the complex physical distortions on the one hand and their subjective severity on the other. We show that perceived distortion can be measured as a psychophysical scaling function using a VR experiment with accurately simulated PAL distortions. Despite the multi-dimensional space of physical distortions, the measured perception is well represented as a 1D scaling function; distortions are perceived less with negative far correction, suggesting an advantage for short-sighted people. Beyond that, our results successfully demonstrate that psychophysical scaling with ordinal embedding methods can investigate complex perceptual phenomena like lens distortions that affect geometry, stereo, and motion perception. Our approach provides a new perspective on lens design based on modeling visual processing that could be applied beyond distortions. We anticipate that future PAL designs could be improved using our method to minimize subjectively discomforting distortions rather than merely optimizing physical parameters.
PubMed: 38368485
DOI: 10.1038/s41598-024-54368-3 -
Attention, Perception & Psychophysics Apr 2024Localizing tactile stimulation is an important capability for everyday function and may be impaired in people with persistent pain. This study sought to provide a...
Localizing tactile stimulation is an important capability for everyday function and may be impaired in people with persistent pain. This study sought to provide a detailed description of lumbar spine tactile localization accuracy in healthy individuals. Sixty-nine healthy participants estimated where they were touched at nine different points, labelled in a 3 × 3 grid over the lumbar spine. Mislocalization between the perceived and actual stimulus was calculated in horizontal (x) and vertical (y) directions, and a derived hypotenuse (c) mislocalization was calculated to represent the direct distance between perceived and actual points. In the horizontal direction, midline sites had the smallest mislocalization. Participants exhibited greater mislocalization for left- and right-sided sites, perceiving sites more laterally than they actually were. For all vertical values, stimulated sites were perceived lower than reality. A greater inaccuracy was observed in the vertical direction. This study measured tactile localization for the low back utilizing a novel testing method. The large inaccuracies point to a possible distortion in the underlying perceptual maps informing the superficial schema; however, further testing comparing this novel method with an established tactile localization task, such as the point-to-point method, is suggested to confirm these findings.
Topics: Humans; Male; Female; Adult; Touch Perception; Young Adult; Touch; Space Perception; Adolescent; Lumbar Vertebrae; Lumbosacral Region
PubMed: 38332382
DOI: 10.3758/s13414-024-02843-4 -
Current Biology : CB Mar 2024Visual shape perception is central to many everyday tasks, from object recognition to grasping and handling tools. Yet how shape is encoded in the visual system remains...
Visual shape perception is central to many everyday tasks, from object recognition to grasping and handling tools. Yet how shape is encoded in the visual system remains poorly understood. Here, we probed shape representations using visual aftereffects-perceptual distortions that occur following extended exposure to a stimulus. Such effects are thought to be caused by adaptation in neural populations that encode both simple, low-level stimulus characteristics and more abstract, high-level object features. To tease these two contributions apart, we used machine-learning methods to synthesize novel shapes in a multidimensional shape space, derived from a large database of natural shapes. Stimuli were carefully selected such that low-level and high-level adaptation models made distinct predictions about the shapes that observers would perceive following adaptation. We found that adaptation along vector trajectories in the high-level shape space predicted shape aftereffects better than simple low-level processes. Our findings reveal the central role of high-level statistical features in the visual representation of shape. The findings also hint that human vision is attuned to the distribution of shapes experienced in the natural environment.
Topics: Humans; Visual Perception; Vision, Ocular; Perceptual Distortion; Environment; Pattern Recognition, Visual; Photic Stimulation
PubMed: 38218184
DOI: 10.1016/j.cub.2023.12.039