Visual Importance- and Discomfort Region-Selective Low-Pass Filtering for Reducing Visual Discomfort in Stereoscopic Displays

<p>Virtual Reality (VR) applications on Head Mounted Displays (HMDs) are now more common and accessible for personal viewing than before with the introduction of consumer-level devices like the Oculus Rift. However, exposure to VR applications on HMDs results in significant discomfort for the majority of people, the severity of which can both increase or decrease after repeated exposures. This is disadvantageous for the development and adoption of VR, as a long adaptation period cannot be relied on for making Virtual Environments palatable. Symptoms of discomfort caused by the viewing of content on VR devices including HMDs are historically described as “Simulator Sickness” and include eye fatigue, headaches, nausea and sweating; symptoms very similar to those experienced by sufferers of motion sickness. We refer to the specific subset of Simulator Sickness Symptoms caused by visual stimuli as symptoms of “Visual Discomfort”. A conflict between accommodation and vergence depth cues on stereoscopic displays is known to be a significant cause of visual discomfort. This report describes a psychophysical evaluation used for judging the effectiveness of dynamic Depth of Field (DoF) blurring on reducing visual discomfort caused by initial exposure to stereoscopic content on HMDs. Our DoF implementation adjusts the focal region of stereoscopic content based on an estimation of users’ view vectors in real time and is realised in a commercial game engine. Participants report a significant reduction of visual discomfort using a simulator sickness questionnaire when DoF blurring is enabled. On average, a 34% reduction in our sickness measure is observed, indicating that dynamic DoF blurring is an effective rendering technique for reducing visual discomfort.</p>

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fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine

Cephalalgia ◽

10.1177/0333102411409076 ◽

2011 ◽

Vol 31 (8) ◽

pp. 925-936 ◽

Cited By ~ 89

Author(s):

Jie Huang ◽

Xiaopeng Zong ◽

Arnold Wilkins ◽

Brian Jenkins ◽

Andrea Bozoki ◽

...

Keyword(s):

Cortical Activation ◽

Visual Discomfort ◽

Beneficial Effects ◽

Migraine Headaches ◽

Perceptual Illusions ◽

Low Pass ◽

Perceptual Distortions ◽

Photosensitive Epilepsy ◽

Visual Cortical ◽

And Control

Background: Certain patterns can induce perceptual illusions/distortions and visual discomfort in most people, headaches in patients with migraine, and seizures in patients with photosensitive epilepsy. Visual stimuli are common triggers for migraine attacks, possibly because of a hyperexcitability of the visual cortex shown in patients with migraine. Precision ophthalmic tints (POTs) are claimed to reduce perceptual distortions and visual discomfort and to prevent migraine headaches in some patients. We report an fMRI visual cortical activation study designed to investigate neurological mechanisms for the beneficial effects of POTs in migraine. Methods: Eleven migraineurs and 11 age- and sex-matched non-headache controls participated in the study using non-stressful and stressful striped patterns viewed through gray, POT, and control coloured lenses. Results: For all lenses, controls and migraineurs did not differ in their response to the non-stressful patterns. When the migraineurs wore gray lenses or control coloured lenses, the stressful pattern resulted in activation that was greater than in the controls. There was also an absence of the characteristic low-pass spatial frequency (SF) tuning in extrastriate visual areas. When POTs were worn, however, both cortical activation and SF tuning were normalized. Both when observing the stressful pattern and under more typical viewing conditions, the POTs reduced visual discomfort more than either of the other two lenses. Conclusion: The normalization of cortical activation and SF tuning in the migraineurs by POTs suggests a neurological basis for the therapeutic effect of these lenses in reducing visual cortical hyperactivation in migraine.

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Mitigating Visual Discomfort on Head Mounted Displays using Estimated Gaze Dependent Depth of Field

10.26686/wgtn.17014013 ◽

2021 ◽

Author(s):

◽

Kieran Carnegie

Keyword(s):

Depth Of Field ◽

Focal Region ◽

Adaptation Period ◽

Simulator Sickness ◽

Visual Discomfort ◽

Initial Exposure ◽

Stereoscopic Displays ◽

Specific Subset ◽

Head Mounted Displays ◽

Psychophysical Evaluation

<p>Virtual Reality (VR) applications on Head Mounted Displays (HMDs) are now more common and accessible for personal viewing than before with the introduction of consumer-level devices like the Oculus Rift. However, exposure to VR applications on HMDs results in significant discomfort for the majority of people, the severity of which can both increase or decrease after repeated exposures. This is disadvantageous for the development and adoption of VR, as a long adaptation period cannot be relied on for making Virtual Environments palatable. Symptoms of discomfort caused by the viewing of content on VR devices including HMDs are historically described as “Simulator Sickness” and include eye fatigue, headaches, nausea and sweating; symptoms very similar to those experienced by sufferers of motion sickness. We refer to the specific subset of Simulator Sickness Symptoms caused by visual stimuli as symptoms of “Visual Discomfort”. A conflict between accommodation and vergence depth cues on stereoscopic displays is known to be a significant cause of visual discomfort. This report describes a psychophysical evaluation used for judging the effectiveness of dynamic Depth of Field (DoF) blurring on reducing visual discomfort caused by initial exposure to stereoscopic content on HMDs. Our DoF implementation adjusts the focal region of stereoscopic content based on an estimation of users’ view vectors in real time and is realised in a commercial game engine. Participants report a significant reduction of visual discomfort using a simulator sickness questionnaire when DoF blurring is enabled. On average, a 34% reduction in our sickness measure is observed, indicating that dynamic DoF blurring is an effective rendering technique for reducing visual discomfort.</p>

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Reducing visual discomfort of 3D stereoscopic displays with gaze-contingent depth-of-field

Proceedings of the ACM Symposium on Applied Perception - SAP '14 ◽

10.1145/2628257.2628259 ◽

2014 ◽

Cited By ~ 35

Author(s):

Andrew T. Duchowski ◽

Donald H. House ◽

Jordan Gestring ◽

Rui I. Wang ◽

Krzysztof Krejtz ◽

...

Keyword(s):

Depth Of Field ◽

Visual Discomfort ◽

Stereoscopic Displays

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Visual discomfort in stereoscopic displays: a review

10.1117/12.705527 ◽

2007 ◽

Cited By ~ 67

Author(s):

Marc T. M. Lambooij ◽

Wijnand A. IJsselsteijn ◽

Ingrid Heynderickx

Keyword(s):

Visual Discomfort ◽

Stereoscopic Displays

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Application of cross correlation to HREM images of surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128080 ◽

1987 ◽

Vol 45 ◽

pp. 754-755

Author(s):

D. E. Luzzi ◽

L. D. Marks ◽

M. I. Buckett

Keyword(s):

Cross Correlation ◽

A Priori ◽

Matrix Material ◽

Correlation Method ◽

Accurate Knowledge ◽

Complex Image ◽

Fourier Filtering ◽

The Matrix ◽

Low Pass ◽

Data Reduction Technique

As the HREM becomes increasingly used for the study of dynamic localized phenomena, the development of techniques to recover the desired information from a real image is important. Often, the important features are not strongly scattering in comparison to the matrix material in addition to being masked by statistical and amorphous noise. The desired information will usually involve the accurate knowledge of the position and intensity of the contrast. In order to decipher the desired information from a complex image, cross-correlation (xcf) techniques can be utilized. Unlike other image processing methods which rely on data massaging (e.g. high/low pass filtering or Fourier filtering), the cross-correlation method is a rigorous data reduction technique with no a priori assumptions.We have examined basic cross-correlation procedures using images of discrete gaussian peaks and have developed an iterative procedure to greatly enhance the capabilities of these techniques when the contrast from the peaks overlap.

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The S-SH Confusion Test and the Effects of Frequency Lowering

Journal of Speech Language and Hearing Research ◽

10.1044/2018_jslhr-h-18-0267 ◽

2019 ◽

Vol 62 (5) ◽

pp. 1486-1505

Author(s):

Joshua M. Alexander

Keyword(s):

Cognitive Processing ◽

Hearing Aids ◽

Response Times ◽

Nonlinear Frequency ◽

Low Frequencies ◽

Frequency Compression ◽

Negative Side ◽

Minimal Word ◽

Low Pass ◽

Negative Side Effects

PurposeFrequency lowering in hearing aids can cause listeners to perceive [s] as [ʃ]. The S-SH Confusion Test, which consists of 66 minimal word pairs spoken by 6 female talkers, was designed to help clinicians and researchers document these negative side effects. This study's purpose was to use this new test to evaluate the hypothesis that these confusions will increase to the extent that low frequencies are altered.MethodTwenty-one listeners with normal hearing were each tested on 7 conditions. Three were control conditions that were low-pass filtered at 3.3, 5.0, and 9.1 kHz. Four conditions were processed with nonlinear frequency compression (NFC): 2 had a 3.3-kHz maximum audible output frequency (MAOF), with a start frequency (SF) of 1.6 or 2.2 kHz; 2 had a 5.0-kHz MAOF, with an SF of 1.6 or 4.0 kHz. Listeners' responses were analyzed using concepts from signal detection theory. Response times were also collected as a measure of cognitive processing.ResultsOverall, [s] for [ʃ] confusions were minimal. As predicted, [ʃ] for [s] confusions increased for NFC conditions with a lower versus higher MAOF and with a lower versus higher SF. Response times for trials with correct [s] responses were shortest for the 9.1-kHz control and increased for the 5.0- and 3.3-kHz controls. NFC response times were also significantly longer as MAOF and SF decreased. The NFC condition with the highest MAOF and SF had statistically shorter response times than its control condition, indicating that, under some circumstances, NFC may ease cognitive processing.ConclusionsLarge differences in the S-SH Confusion Test across frequency-lowering conditions show that it can be used to document a major negative side effect associated with frequency lowering. Smaller but significant differences in response times for correct [s] trials indicate that NFC can help or hinder cognitive processing, depending on its settings.

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Perceptual Learning of Vocoded Speech With and Without Contralateral Hearing: Implications for Cochlear Implant Rehabilitation

Journal of Speech Language and Hearing Research ◽

10.1044/2020_jslhr-20-00385 ◽

2020 ◽

pp. 1-10

Author(s):

Martin Chavant ◽

Alexis Hervais-Adelman ◽

Olivier Macherey

Keyword(s):

Cochlear Implant ◽

Perceptual Learning ◽

Speech Signal ◽

Training Phase ◽

Monosyllabic Words ◽

Low Pass ◽

Contralateral Ear ◽

Number Of Individuals ◽

Insight Into ◽

Vocoded Speech

Purpose An increasing number of individuals with residual or even normal contralateral hearing are being considered for cochlear implantation. It remains unknown whether the presence of contralateral hearing is beneficial or detrimental to their perceptual learning of cochlear implant (CI)–processed speech. The aim of this experiment was to provide a first insight into this question using acoustic simulations of CI processing. Method Sixty normal-hearing listeners took part in an auditory perceptual learning experiment. Each subject was randomly assigned to one of three groups of 20 referred to as NORMAL, LOWPASS, and NOTHING. The experiment consisted of two test phases separated by a training phase. In the test phases, all subjects were tested on recognition of monosyllabic words passed through a six-channel “PSHC” vocoder presented to a single ear. In the training phase, which consisted of listening to a 25-min audio book, all subjects were also presented with the same vocoded speech in one ear but the signal they received in their other ear differed across groups. The NORMAL group was presented with the unprocessed speech signal, the LOWPASS group with a low-pass filtered version of the speech signal, and the NOTHING group with no sound at all. Results The improvement in speech scores following training was significantly smaller for the NORMAL than for the LOWPASS and NOTHING groups. Conclusions This study suggests that the presentation of normal speech in the contralateral ear reduces or slows down perceptual learning of vocoded speech but that an unintelligible low-pass filtered contralateral signal does not have this effect. Potential implications for the rehabilitation of CI patients with partial or full contralateral hearing are discussed.

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