Perceptual Phenomena Research Articles

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The Influence of Alpha Frequency on Temporal Binding across the Senses: Response to the Special Focus.

The papers collected in this Special Focus, prompted by S. Buergers and U. Noppeney [The role of alpha oscillations in temporal binding within and across the senses. Nature Human Behaviour, 6, 732-742, 2022], have raised several interesting ideas, arguments, and empirical results relating to the alpha temporal resolution hypothesis. Here we briefly respond to these, and in the process emphasize four challenges for future research: defining the scope and limitation of the hypothesis; developing experimental paradigms and study designs that rigorously test its tenets; decomposing the scalp-level signal and isolating underlying neural circuits; and bringing uniformity to the current diversity of analysis and statistical methods. Addressing these challenges will facilitate the progression from merely correlating alpha frequency with various perceptual phenomena to establishing whether and (if so) how alpha frequency influences sensory integration and segregation.

Quantum approach to jam session

A quantum mechanical approach to the psychoacoustic effect of Shepard tones has been explored. Melodic intervals are represented by qubits. The phenomenon of bistable perception of intervals and their acoustic collapse has been considered and described in the language of quantum mechanics. It is shown that the perception of intervals can be understood as a result of measuring the standard basis vector in different bases rotated in a plane of the chroma circle. For comparison, the Stern-Gerlach and photon polarization experiments have been cited to show an analogy. A quantum analog of the Shepard interval source, with a photonic random number generator, has been proposed. The topic of quantum entanglement transferred to the field of sound and psychoacoustics is also discussed. Based on quantum-like calculations, it has been shown how disturbances in time coherence between the playing of different music band members could affect the modification of the melody.

Examining Illusory Touch Perception in Virtual Reality among Virtual Reality Users

The phenomenon of illusory touch perception in virtual reality (VR) is a subject of increasing intrigue within online VR communities, where users report experiencing tactile sensations in the absence of direct physical contact, triggered solely by visual stimuli. This paper presents an exploratory study aimed at understanding the underlying mechanisms that contribute to the development of such illusory touch perceptions in immersive virtual environments. Through an online survey targeting VR users, this study collected qualitative data on the nature and frequency of these experiences. The survey was complemented by a review of existing literature on touch perception and multisensory integration, providing a foundational understanding of how sensory information is processed and perceived. The findings suggest that certain visual cues in VR can evoke tactile sensations, a phenomenon that may be enhanced by the immersive quality of the virtual environment and the user's previous sensory experiences and expectations. This paper discusses potential contributors to the phenomenon, such as the realism of the virtual environment, the user's level of immersion and presence, and the congruence of multisensory stimuli. Although this study sheds light on the conditions that may facilitate illusory touch perception in VR, the complexity of human sensory processing necessitates further research. Controlled experimental studies are required to establish a causal relationship between specific factors and the experience of illusory touch in VR, which could have significant implications for the fields of virtual reality and sensory augmentation technology.

An objective measurement approach to quantify the perceived distortions of spectacle lenses

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.

“Die Natur ist hier … zu Musik geworden”: György Ligeti and (Musical) Nature

AbstractThis article traces references to nature and naturalism (understood as an attempt to ground and legitimize art in natural phenomena) in Ligeti's writings, but also in selected aspects of his oeuvre. The references to nature recur here in various manifestations, with romantic depictions of nature appearing alongside more recent, modernist approaches. The concept of nature is associated with the romantic setting for human emotions, with the discovery of scientific laws, with listening to soundscape, with phenomena of auditory perception and with the spectral explorations of sound. Although nature is not a central, strategic concept for Ligeti, it remains a constant, even if hidden, context for his work, a point of reference.

The Reality of a Head-Mounted Display (HMD) Environment Tested via Lightness Perception.

Head-mounted displays (HMDs) are becoming more and more popular as a device for displaying a virtual reality space, but how real are they? The present study attempted to quantitatively evaluate the degree of reality achieved with HMDs by using a perceptual phenomenon as a measure. Lightness constancy is an ability that is present in human visual perception, in which the perceived reflectance (i.e., the lightness) of objects appears to stay constant across illuminant changes. Studies on color/lightness constancy in humans have shown that the degree of constancy is high, in general, when real objects are used as stimuli. We asked participants to make lightness matches between two virtual environments with different illuminant intensities, as presented in an HMD. The participants' matches showed a high degree of lightness constancy in the HMD; our results marked no less than 74.2% (84.8% at the maximum) in terms of the constancy index, whereas the average score on the computer screen was around 65%. The effect of head-tracking ability was confirmed by disabling that function, and the result showed a significant drop in the constancy index but that it was equally effective when the virtual environment was generated by replay motions. HMDs yield a realistic environment, with the extension of the visual scene being accompanied by head motions.

Elucidating the Visual Snow Spectrum: A Latent Class Analysis Study.

People with visual snow syndrome (VSS) experience a range of perceptual phenomena, in addition to visual snow (VS; flickering pinpricks of light throughout the visual field). We investigated the patterns of perceptual phenomena associated with VSS in a large sample of people without prior knowledge of VSS or its associated symptoms. Methods and Measures. Two thousand participants completed a screening questionnaire assessing the frequency and severity of perceptual phenomena associated with VSS. We used latent class analysis (LCA), a clustering technique which identifies qualitatively different subgroups within a given population, to investigate whether the presence (or absence) of VS impacted class structure. Of 1,846 participants included for analysis, 41.92% experienced VS some of the time, including 4.49% who had VSS without prior knowledge. The mean number of perceptual phenomena experienced was 2.03. Optimal four-class LCA solutions did not substantially differ whether VS was included in the model; instead, classes differed in the frequency and total number of symptoms experienced. Discussion. Our results suggest that the perceptual phenomena associated with VSS are likely to be common in the general population and do not necessarily indicate an underlying pathology. We also showed that visual snow itself does not explain the presence of other perceptual phenomena.

“Experiencing perception”: A collection of class demonstrations and activities to engage students in sensation & perception courses

ABSTRACT Demonstrations have been used to illustrate perceptual phenomena for many years, since they are useful in increasing students’ interest. I have been teaching Perception and Attention for the past 15 years and I have often used demonstrations in class. Due to the pandemic, I had to find alternative demonstrations that did not require direct manipulation and could be easily performed from home. This led to changes in the selection of demonstrations and also in my teaching strategies. In this paper I present the result of this process, which is a collection of 15 class activities. Each activity includes complementary materials (reading assignments and reflection questions) to increase students’ engagement and learning. In presenting this collection of activities I will also reflect on some of the challenges and opportunities that I have found regarding the use of demonstrations in class with groups of different sizes and cultural backgrounds.

Механізми впливу інформаційної агресії на свідомість громадян: соціально-психологічний аспект

The article defines the mechanisms of information aggression influence on citizens’ consciousness, taking into account the social and psychological characteristics and components of such influence. The relevant mechanisms are presented as cognitive, emotional and social processes that affect the nature of information perception by individuals or groups, their thinking, activity, direction of activity, are used to form and change motives, attitudes, behaviour and needs. These include mechanisms and effects of social perception, mechanisms and phenomena of perception, memory, attention, influence on public opinion, manipulation of consciousness and informational violence. Attention is drawn to the fact that the mechanisms of information aggression influence on citizens’ consciousness are constantly being improved and modified. It is emphasized that the use of mechanisms of destructive informational and psychological influence in conditions of information aggression allows to program actions and behaviour, manipulate consciousness and misinform citizens, predisposing them to make the right decision and behaviour. Understanding the mechanisms of information aggression influence, which poses a threat to the national interests and national security of Ukraine in the information sphere, is one of the ways to ensure individual, group and mass consciousness of citizens. Prospects for further research are outlined, which consist in determining the specifics of information aggression influence on different population groups in the context of the problem of countering the consciousness’ manipulation and the formation of critical thinking as a security factor of citizens.

Exploring heart rate variability in alcohol-dependent subjects using frequency-domain analysis

Background: Alcohol-seeking behavior despite being aware of its adverse effects is defined as alcohol dependence (AD). AD syndrome is a cluster of physiological, behavioral, psychological, and perceptual phenomena that develop subsequent to chronic alcohol ingestion. Ethanol is a potent central nervous system depressant that causes toxic damage to the vasomotor and cardiac autonomic nerve fibers which leads to autonomic imbalance leading to arrhythmias and sudden cardiac deaths. Recording and analyzing the heart rate variability (HRV) using the frequency-domain method delineate the autonomic imbalance in alcoholic individuals which may be due to reduced parasympathetic activity and/or sympathetic hyperactivity. Aims and Objectives: The aim of the study was to assess and compare the cardiac autonomic function between the AD group and the non-alcoholic control group using the frequency domain method of HRV. Materials and Methods: A total of 55 alcohol-dependent individuals in the age group of 20–55 years were selected from the psychiatry outpatient department, based on the International Classification of Diseases-10 (Diagnostic and Statistical Manual -IV) criteria as the study population. Fifty-five age and gender-matched healthy volunteers from the master health check-up scheme from the Department of Community Medicine were selected as the control population. Institutional Ethical Committee clearance was obtained. After obtaining informed written consent from the individuals, the short-term 5 min HRV was recorded in the supine position with eyes closed. The results were analyzed and interpreted. Statistical analysis was done using the software Statistical Package for the Social Sciences version 21.0. Results: The frequency domain parameters high frequency (HF) which is a specific marker of parasympathetic activity was significantly reduced, and low frequency (LF) which is a marker of sympathetic activity was significantly increased in the alcoholic group compared to the non-alcoholic group, respectively. The LF: HF ratio which denotes sympathetic-vagal balance was increased in the alcohol-dependent group. Conclusion: HF was decreased, LF and LF: HF ratio was increased in alcoholic-dependent individuals indicating autonomic imbalance with reduced parasympathetic activity and increased sympathetic activity which suggests that alcohol affects the cardiac autonomic status. This concludes that the frequency domain method of HRV could be used as a short-term non-invasive test to assess cardiac autonomic dysfunction in alcohol-dependent individuals.

Participant Perspectives on the Impact of a School-Based, Experiential Food Education Program Across Childhood, Adolescence, and Young Adulthood

ObjectiveExplore participant perceptions of involvement in an experiential food education program during elementary school and the scope and extent of program influence on food decisions. DesignFocus groups with current participants and program alumni. SettingWashington, DC. ParticipantsThirty-nine elementary school students and 39 program alumni ranging from middle school through university students. Phenomenon of InterestParticipant perceptions of program impact from childhood into adolescence and young adulthood. AnalysisInductive thematic analysis. ResultsNine emergent themes were identified, spread over 3 categories of program impact: immediate, beyond the classroom, and sustained. Immediate program impact themes came from all participants and included enjoyment, hands-on learning, and fostering connection. Beyond the classroom, older elementary students and alumni expressed perceived shifts in individual and family food intake, involvement in household food practices, and desire for fresh food options at school. Themes of sustained program impact among alumni participants were an appreciation for fresh food, openness to trying new foods, and confidence to make informed food decisions. Conclusions and ImplicationsFindings provide a deeper understanding of participant perspectives on the impact of participation in a school-based experiential food education program and a basis for further research on the role of early exposure to food education in influencing food decisions as children grow older.

The phenomenon of music perception in the aspect of teaching in performing classes of pedagogical educational institutions

The phenomenon of music perception in the aspect of teaching in performing classes of pedagogical educational institutions

Chromatic processing and receptive-field structure in neurons of the anterior optic tract of the honeybee brain.

Color vision in honeybees is a well-documented perceptual phenomenon including multiple behavioral tests of trichromaticity and color opponency. Data on the combined color/space properties of high order visual neurons in the bee brain is however limited. Here we fill this gap by analyzing the activity of neurons in the anterior optic tract (AOT), a high order brain region suggested to be involved in chromatic processing. The spectral response properties of 72 units were measured using UV, blue and green light stimuli presented in 266 positions of the visual field. The majority of these units comprise combined chromatic-spatial processing properties. We found eight different neuron categories in terms of their spectral, spatial and temporal response properties. Color-opponent neurons, the most abundant neural category in the AOT, present large receptive fields and activity patterns that were typically opponent between UV and blue or green, particularly during the on-tonic response phase. Receptive field shapes and activity patterns of these color processing neurons are more similar between blue and green, than between UV and blue or green. We also identified intricate spatial antagonism and double spectral opponency in some receptive fields of color-opponent units. Stimulation protocols with different color combinations applied to 21 AOT units allowed us to uncover additional levels of spectral antagonism and hidden inhibitory inputs, even in some units that were initially classified as broad-band neurons based in their responses to single spectral lights. The results are discussed in the context of floral color discrimination and celestial spectral gradients.

Drug-induced musical hallucination.

Musical hallucination is a rare perceptual phenomenon wherein individuals hear music in the absence of external auditory stimuli. This phenomenon occurs across diverse medical conditions and can be triggered by some drugs. The underlying mechanism of drug-induced hallucination is unknown. This study explores drug-induced musical hallucination through a literature review, aiming to investigate its pathophysiology and potential treatment modalities. A literature search was conducted until January 2024 using databases PubMed, WorldCat, Google Scholar, and DOAJ, with keywords "drugs induced musical hallucination" or "drugs" combined with "musical hallucination." The search yielded 24 articles which met inclusion criteria, encompassing 27 cases. The average patient age was 58.3years, with 67.9% females. Prevalent conditions among cases included hearing impairments, psychiatric disorders, cancers, and neurodegenerative conditions. Common trigger drugs comprised antidepressants, opioids, anti-Parkinson drugs, ketamine, and voriconazole. Musical hallucination descriptions varied widely, and 6 patients reported concurrent visual hallucinations. The onset of symptoms ranged from 75min to 240days. Treatment strategies included termination of trigger drugs, dosage reduction, alteration of administration routes or formula, switching to similar drugs, or addition of antidepressants, sedatives, or atypical antipsychotic medications. Musical hallucinations completely disappeared in 24/27 (88.9%) patients but continued in 3/27 (11.1%) patients. The current study concludes that drug-induced musical hallucination may arise from altering neurotransmitter/receptor balance and intricate interactions between trigger drugs and underlying conditions.

Phenomenology as an approach to seeing the aesthetics of ugliness in contemporary art designs

With a descriptive and analytical approach, it discusses the concept of phenomenology as an approach to seeing the aesthetics of ugliness as one of the concepts associated with the aesthetic experience in contemporary art designs, as it is the result of communication between artistic production and the recipient, which leads to creating a state of aesthetic pleasure. A phenomenological method is used to uncover the aesthetics of ugly and to connect ugliness and beauty since ugliness in aesthetics incorporates beauty as a modern aesthetic vision from the phenomenological perspective. The study investigated aesthetics as a phenomenon of perception, sensory knowledge, and the aesthetic response to the production of designs in contemporary art, represented by achieving a status of aesthetic pleasure, and the phenomenological approach can be applied to see the aesthetics of ugliness in contemporary design, and there is a relationship between the aesthetics of ugliness and the aesthetic experience in producing contemporary design, and it reached the possibility of applying the phenomenological approach to appreciation and criticism with an aesthetic vision of ugliness, by transforming the influence of phenomenological thought as a method into an aesthetic concept. To build the design for a more in-depth vision in a new analytical reading, and to have a merit in the study and production of designs that began with the art of the event and ended as digital art with technical effects, with its components (intentionality).

The Effect of Interocular Contrast Differences on the Appearance of Augmented Reality Imagery

Augmented reality (AR) devices seek to create compelling visual experiences that merge virtual imagery with the natural world. These devices often rely on wearable near-eye display systems that can optically overlay digital images to the left and right eyes of the user separately. Ideally, the two eyes should be shown images with minimal radiometric differences (e.g., the same overall luminance, contrast, and color in both eyes), but achieving this binocular equality can be challenging in wearable systems with stringent demands on weight and size. Basic vision research has shown that a spectrum of potentially detrimental perceptual effects can be elicited by imagery with radiometric differences between the eyes, but it is not clear whether and how these findings apply to the experience of modern AR devices. In this work, we first develop a testing paradigm for assessing multiple aspects of visual appearance at once, and characterize five key perceptual factors when participants viewed stimuli with interocular contrast differences. In a second experiment, we simulate optical see-through AR imagery using conventional desktop LCD monitors and use the same paradigm to evaluate the multi-faceted perceptual implications when the AR display luminance differs between the two eyes. We also include simulations of monocular AR systems (i.e., systems in which only one eye sees the displayed image). Our results suggest that interocular contrast differences can drive several potentially detrimental perceptual effects in binocular AR systems, such as binocular luster, rivalry, and spurious depth differences. In addition, monocular AR displays tend to have more artifacts than binocular displays with a large contrast difference in the two eyes. A better understanding of the range and likelihood of these perceptual phenomena can help inform design choices that support high-quality user experiences in AR.

Invited Session IV: Extended reality--applications in vision science and beyond: Improving augmented reality through perceptual science.

Augmented reality (AR) systems make it possible to present visual stimuli that intermix and interact with people's view of the natural world. But building an AR system that merges stimuli with our natural visual experience is hard. AR systems often suffer from technical and visual limitations, such as small eyeboxes, limited brightness, and narrow visual field coverage. An integral part of AR system development, therefore, is perceptual research that improves our understanding of when and why these limitations matter. I will describe a suite of perceptual studies designed to provide guidance for engineers on the visibility and appearance of wearable optical see-through AR displays. Our results highlight the idiosyncrasies of how our visual system integrates information from the two eyes, the multifaceted nature of perceptual phenomena in AR, and the trade-offs that are currently necessary to create an AR system that is both wearable and compelling.

Perceptual Phenomena Cannot Be Approached from a Single Perspective.

This article explores the relationship between neurophysiology and phenomenology in the context of ambiguous figures. Divided into three parts, the study investigates new forms of stimulus and experience errors that arise from ambiguous figures. Part 1 discusses the limitations of a single-disciplinary approach and cautions against relying only on neurophysiological explanations for perceptions. A sole reliance on neurophysiological explanations can lead to stimulus and experience errors, as well as to the development of an unfounded mind/body dualism. Part 2 focusses on the stimulus error associated with ambiguous figures. It also shows how the Mona Lisa's ambiguous expression can cause the experience error. Unlike other forms of ambiguous figures, different expressions of Mona Lisa are perceived when seen in different definitions. It is shown how assigning a higher ontological status to one of the expressions because it aligns with our knowledge of the nervous system, as conjectured by some authors, gives rise to the experience error. Part 3 emphasises the importance of complementing neurophysiological interpretations with phenomenological ones for a better understanding of perceptual phenomena. Phenomenology provides constraints and corrections to neurophysiology, whereas neurophysiology informs phenomenology through empirical findings. The theory of levels of reality is introduced as a framework to underlie the connections and dependencies between different perspectives. Using both neurophysiological and phenomenological approaches, a comprehensive understanding of perceptual phenomena emerges, surpassing the limitations of each discipline. This method encourages a holistic view of perception, where neurophysiology and phenomenology coexist, complementing and enriching each other's insights.

State-dependent alterations of implicit emotional dominance during binocular rivalry in subthreshold depression.

Binocular rivalry, a visual perception phenomenon where two or more percepts alternate every few seconds when distinct stimuli are presented to the two eyes, has been reported as a biomarker in several psychiatric disorders. It is unclear whether abnormalities of binocular rivalry in depression could occur when emotional rivaling stimuli are used, and if so, whether an emotional binocular rivalry test could provide a trait-dependent or state-dependent biomarker. In the current study, 34 individuals with subthreshold depression and 31 non-depressed individuals performed a binocular rivalry task associated with implicit emotional processing. Participants were required to report their perceived orientations of the rival gratings in the foreground and to neglect emotional face stimuli in the background. The participants were retested after an approximately 4-month time interval. Compared to the non-depressed group, the subthreshold depression group showed significantly longer perceptual dominance durations of the grating with emotional faces as the background (i.e., implicit emotional dominance) at the initial assessment. However, the abnormality was not found at the follow-up assessment. More importantly, we found smaller changes in depressive severity at the follow-up assessment for individuals displaying longer emotional dominance at the initial assessment than for individuals with weaker emotional dominance. The current emotional binocular rivalry test may provide an objective, state-dependent biomarker for distinguishing individuals with subthreshold depression from non-depressed individuals.