Effect Of Illusion Research Articles

Body Processing in Children and Adolescents with Traumatic Brain Injury: An Exploratory Study.

Dysfunctions in body processing have been documented in adults with brain damage, while limited information is available for children. This study aimed to investigate body processing in children and adolescents with traumatic brain injury (TBI) (N = 33), compared to peers with typical development. Two well-known computerized body-representation paradigms, namely Visual Body Recognition and Visuo-spatial Imagery, were administered. Through the first paradigm, the body inversion and composite illusion effects were tested with a matching to sample task as measures of configural and holistic processing of others’ bodies, respectively. The second paradigm investigated with a laterality judgement task the ability to perform first-person and object-based mental spatial transformations of own body and external objects, respectively. Body stimuli did not convey any emotional contents or symbolic meanings. Patients with TBI had difficulties with mental transformations of both body and object stimuli, displaying deficits in motor and visual imagery abilities, not limited to body processing. Therefore, cognitive rehabilitation of body processing in TBI might benefit from the inclusion of both general training on visuo-spatial abilities and specific exercises aimed at boosting visual body perception and motor imagery.

De Sitter space with generalized Poincaré lens

de Sitter space is an important maximally symmetric vacuum solution of Einstein's field equation, located in a central place in cosmology in explaining the accelerated expansion of the Universe. Here in the view of optics, we propose the de Sitter space with a generalized Poincar\'e lens based on the equivalence between the static curved space-time and the isotropic optical medium. The correspondence of familiar de Sitter space and the Poincar\'e disk can be regarded as a special case therein. We also discover that the generalized de Sitter space has a topological cosmic string kernel in the center which can deflect light in different ways. This feature can be evidenced and visualized in its equivalent generalized Poincar\'e lens with a tunable horizon. To gain more intrinsic understanding, we further introduce its one-dimensional lens. Finally, for a possible application, we implement a multiple source illusion effect in the generalized Poincar\'e lens and find that the energy flow obeys the topological Poincar\'e-Hopf theorem. Our work is an attempt in the fruitful interplay between optics and general relativity and may enlighten other interesting relevant explorations.

Effects of the Mirror Box Illusion on EEG Sensorimotor Rhythms in Voluntary and Involuntary Finger Movements

Effects of the Mirror Box Illusion on EEG Sensorimotor Rhythms in Voluntary and Involuntary Finger Movements

Holistic processing of body stimuli: Evidence of body composite illusion in adults and children.

There is inconsistent evidence that human bodies are processed through holistic processing as it has been widely reported for faces. To assess how configural and holistic processes may develop with age, we administered a visual body recognition task assessing the presence of body inversion and composite illusion effects to white adults (114 participants, 77 women, aged between 18 and 35 years) and children (138 participants, 74 girls, aged between 6 and 11 years). Furthermore, to verify the presence of an own-age bias in body processing, we presented either child or adult bodies to both age groups. Adults and children showed reliable and comparable body inversion and composite illusion effects, confirming the use of configural and holistic body processing. Cross-sectional analysis showed that these perceptual strategies were already reliable in children aged 6-7 years and did not encounter significant changes across childhood. Although we found reliable body inversion and composite illusion effects for both own- and different-age bodies, results pointed to greater composite illusion effects for own-age bodies. This may suggest that sharing similar body structures might facilitate the holistic processing of others' bodies. These findings provide new insights into the development of body-specific perceptual processes and may have theoretical and clinical implications for the evaluation and treatment of body perception disorders in childhood. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Galvanic vestibular stimulation to counteract leans illusion: comparing step and ramped waveforms

Leans is a common type of Spatial Disorientation (SD) illusion that causes pilots to be confused about the position of the aircraft during a flight. This illusion could lead to serious adverse effects and even flight mishaps. Therefore, an effective means to deal with leans is crucial for flight safety. This study aims to investigate the effects of Galvanic Vestibular Stimulation (GVS) technology with different waveforms as a tool to mitigate the negative effects of leans. 20 Air Force pilots participated in leans-induced flight simulation experiment with three GVS conditions (without-GVS, step-GVS, ramped-GVS). Bank angle error, subjective SD, perceived strength, and annoyance were measured as the dependent variables. Analysis revealed that step-GVS and ramped-GVS yielded lower bank angle errors and subjective SD than without-GVS. In addition, annoyance ratings were lower for ramped-GVS than step-GVS. This study suggests that GVS has the potential to be utilised as a counteracting tool to cope with leans. Practitioner summary: Galvanic Vestibular Stimulation (GVS) can be utilised as a tool to counteract the detrimental effects of leans illusion, specifically the ramped style GVS, considering that it is less annoying and distracting for the pilots. In general, GVS induces a roll sensation that can offset the false sensation caused by the leans, which can potentially help maintain flight safety and avoid spatial disorientation-related accidents. Abbreviations: SD: spatial disorientation; GVS: galvanic vestibular stimulation; MSSQ: motion sickness susceptibility questionniare; SSQ: simulator sickness questionnaire; BLE: bluetooth low energy; PCB: printed circuit board; RPM: revolution per minute

Radar Cross Section Approach in Illusion Effects of Transformation Optics-Based Expander

In this paper, analytical calculation has been provided to show illusion perception in electromagnetics expander. For this end, a precise analytical solution has been done for a scattered wave from the expander including an object in the core medium. Also, this analytical calculation has been done for a bare transformed object with different size and constitute parameters (CPs). Illusion perception, in the far field, can be illustrated by comparing the calculated scattered field patterns (SFP) of the object placed inside the expander with SFP of the bare transformed object. Moreover, the same calculation and comparison has been done for nearfield SFP. In continuation, for precise deduction, radar cross sections (RCSs) of both objects have been calculated and plotted using MATLAB. Well functionality in illusion perception has been obtained using comparisons in both analytical SFPs parts and RCSs parts.

Role of visual illusions in the assessment of digital color images of aggressive posterior retinopathy of premature

AIM: To estimate the role of visual illusions in the diagnosis of aggressive posterior retinopathy of prematurity (APROP) using a pediatric retinal camera.
 MATERIAL AND METHODS: A retrospective analysis of images of the fundus structures obtained using a pediatric retinal camera was carried out in 31 children diagnosed with APROP. The children were treated at St. Petersburgs Childrens Hospital N17 of St. Nicholas from January 2011 to December 2018. Based on the analysis of digital colored images of the fundus, the diagnosis of ARN was confirmed in 18 children (58%), and in the remaining 42% of cases (13 children), the diagnosis was revised from APROP to classic ROP (stage 3, with signs of plus disease, zones I or II). Preterm infants with classic ROP were excluded from the study group.
 RESULTS: A total of 14 out of 18 (78%) children with APROP were initially diagnosed with manifestations of classical ROP. Analysis of colored images obtained with a retinal camera showed that all of them manifested Machs bands, which created the effect of a demarcation line or a demarcation ridge at the border of light and dark areas. Although they were manifestations of APROP, these illusions were the reason for the diagnosis of classical ROP along with the designation of stages. The effect of Mach band illusion was neutralized by the study of colored photographs on the monitor screen under high magnification.
 CONCLUSION: Visual illusions create difficulties in the timely diagnosis of APROP during the investigation with a retinal camera. They may influence the treatment of patients and lead to poor outcomes of this most severe form of ROP, including the development of retinal detachment and visual impairment in children.

Design method of reusable reciprocal invisibility and phantom device

Reusable reciprocal invisibility and phantom device is proposed and designed based on multi-folded transformation optics and equivalent components. In comparison with the reported reciprocal invisibility cloaks, the material parameters of the device presented here are homogeneous, and the hiding of the target object does not require any “anti-object” at all, which dramatically breaks through the limitations of the “anti-object” design in previous reciprocal cloak design. Perfectly illusion effect is also found by reasonably setting the material parameters of the restored medium of the device, which can be used to confuse detection radars while hiding target objects. Last but not least, the proposed device has an open structure, which enables the target object enclosed by the device to perform material exchange and simplex transfer of information with the outside world through open channels. In other words, the proposed device has a reusable function, enabling stealth or phantom of new target objects without changing any parameters of the device.

Effects of kinesthetic illusion induced by visual stimulation (KINVIS) therapy on patients with stroke in the subacute phase: a visual analysis based on paralysis severity

ABSTRACT We explored the effect of kinesthetic illusion induced by visual stimulation (KINVIS) therapy on motor function in patients with stroke during the subacute phase based on paralysis severity. The study was performed using an ABAB design (A1, B1, A2, B2; for 10 days each). KINVIS therapy was additionally administered in periods B1 and B2. Ten patients with stroke were classified according to severity. The improvement in upper limb motor function was higher after B1 and B2 than after A1 and A2 in the moderate group. The effect of KINVIS therapy increases the degree of improvement in motor function, especially in the moderate group.

Effects of body ownership illusion during exposure to disgusting stimuli

BackgroundThe Rubber Hand Illusion (RHI) refers to the feeling of ownership of a rubber hand by synchronously stroking the rubber hand and the own hand of a person. Previous research has shown that RHI can be used to simulate skin contact with a disgust-eliciting stimulus. We used a primary disgust elicitor (a living maggot) to replicate this finding and to gather data on disgust habituation during RHI, and effects on in-vivo exposure. MethodsA total of 82 healthy participants (25 males, 57 females) were randomly assigned to one of two conditions; synchronous stroking or asynchronous stroking (control condition) of the rubber/own hand. Subsequently, a maggot was placed on the rubber hand for five minutes. Participants rated experienced disgust at the beginning and end of the exposure. They were also asked if the maggot could be placed on their own hand. ResultsSynchronous stroking successfully elicited RHI, which was associated with higher disgust ratings for the maggot at the beginning of exposure compared to asynchronous stroking. The two conditions did not differ in disgust habituation and the willingness to expose the own hand to the maggot. ConclusionRHI successfully simulated skin contact with a disgust stimulus. Future studies should apply longer exposure intervals and test individuals with higher disgust propensity to detect possible RHI effects on disgust habituation.

In Situ Customized Illusion Enabled by Global Metasurface Reconstruction

AbstractOptical illusion has always attracted extensive attention, as it provides a superior self‐protection ability for both natural animals and human beings. A decade ago, this motivated the study and application of transformation optics, which provides a universal tool to manipulate light for invisibility cloaking and optical illusion. However, mainstream transformation‐optics‐based optical illusions are inherently hindered by the extreme requirements of metamaterial compositions in practice and unfavorably limited by the very large computational cost caused by their bulky state. To overcome these grand challenges, a novel and intelligent optical illusion supported by form‐free metasurfaces via a deep learning architecture is reported, which can not only render a similar illusion effect but also greatly reduces the parameter space in physics. Illustrative examples of conformal metasurfaces are presented, with a high‐fidelity inverse design from either the near‐ or far‐field in the simulation and experiment. Furthermore, a full set of intelligent systems is developed to benchmark the real‐world optical illusion applicability. The work brings the available illusion strategies closer to a wide range of in situ practical‐oriented applications and lays a foundation for the next generation of intelligent metamaterials.

Effects of visual-motor illusion in stroke hemiplegic patients with left-side personal neglect: A report of two cases

ABSTRACT Personal neglect is the neglect of self-body space, which often occurs in patients with unilateral spatial neglect (USN), but lacks a dedicated rehabilitation. The purpose of this study was to investigate the effects of visual-motor illusion (VMI) on two-stroke hemiplegic patients with left-side personal neglect. Case 1 was a 53-year-old man diagnosed with a right lenticulostriate artery infarction. Case 2 was a 76-year-old woman diagnosed with a right middle cerebral artery infarction. USN symptoms were not observed in either patient in the desk USN assessment, but personal neglect and USN symptoms in daily life were observed in both patients. Intervention effects were verified using an ABA design, comprising a 5-day three-phase (A1, B, A2). In phase B, VMI was performed on the paralyzed upper limb for 10 min in addition to conventional physical therapy. Outcomes measures were the Fluff test, Catherine Bergego Scale (CBS), Fugl-Meyer Assessment (FMA), and Functional Independence Measure (FIM). In both patients, no improvements were noted in FMA, but improvements were observed in the Fluff test, CBS, and FIM in phase B; these effects were retained in phase A2. Therefore, VMI may have contributed to improvements in Personal neglect and USN symptoms in daily life.

The effect of the full-body illusion to an intelligent avatar on executive function and personality trait

The effect of the full-body illusion to an intelligent avatar on executive function and personality trait

The body-ownership is unconsciously distorted in the brain: An event-related potential study of rubber hand illusion

Many studies have reported that bottom-up multisensory integration of visual, tactile, and proprioceptive information can distort our sense of body-ownership, producing rubber hand illusion (RHI). There is less evidence about when and how the body-ownership is distorted in the brain during RHI. To examine whether this illusion effect occurs preattentively at an early stage of processing, we monitored the visual mismatch negativity (vMMN) component (the index of automatic deviant detection) and N2 (the index for conflict monitoring). Participants first performed an RHI elicitation task in a synchronous or asynchronous setting and then finished a passive visual oddball task in which the deviant stimuli were unrelated to the explicit task. A significant interaction between Deviancy (deviant hand vs. standard hand) and Group (synchronous vs. asynchronous) was found. The asynchronous group showed clear mismatch effects in both vMMN and N2, while the synchronous group had such effect only in N2. The results indicate that after the elicitation of RHI bottom-up integration could be retrieved at the early stage of sensory processing before top-down processing, providing evidence for the priority of the bottom-up processes after the generation of RHI and revealing the mechanism of how the body-ownership is unconsciously distorted in the brain.

Price promotions in vertically-related market: Instant discount vs. gift card

Price promotional tools, such as instant discount and gift card, are commonly used by firms, particularly those in vertically-related markets (including suppliers with direct channels and their retailers), to stimulate purchases. Compared with instant discount, gift card promotion leads consumers to perceive a delay discounting effect by discounting the gift card face value upon redemptions due to delayed reward payments, while it endows consumers with a perception of a price illusion effect that induces multiple mental reductions of purchasing costs despite a single gain. We develop a theoretical model to examine how a supplier and its retailer, under consideration of consumers’ purchasing perceptions, strategically use the above two promotional tools. We find that in a fully covered market (i.e., all consumers choose to buy), despite competition, the supplier will not provide a price promotion under consumers’ weak price illusion effect (but stronger than the delay discounting effect), while under consumers’ strong price illusion effect, if neither firm offers a price promotion, both firms could benefit. By contrast, in a partially covered market (i.e., some consumers choose not to buy and each firm acts like a monopoly), both firms benefit from price promotions under market broadening, and their preferred promotional tool becomes the instant discount rather than the gift card promotion as consumers’ price illusion effect and the marked price decrease. Additionally, the two competing firms’ choices of promotional tools might lead to a Prisoner’s dilemma, where the instant discount promotion is a dominant strategy, whereas the gift card promotion makes both firms better off. We provide some guidelines for suppliers and retailers to offer promotional tools in different covered markets, taking purchasing perceptions of consumers and marked prices of products into consideration.

Quantitative study of asymmetry in the manifestation of the wings-in and wings-out versions of the Müller-Lyer illusion.

The present study investigated whether the asymmetry in magnitude between the wings-in and wings-out versions of the Müller-Lyer illusion can be explained by the manifestation of accompanying effects of the filled-space illusion. In psychophysical experiments, the three-dot stimuli were used, and in different series, a single set of the Müller-Lyer wings was attached to the left or to right terminating dot. To check whether the summation of illusory effects occurs, experiments with two sets of the wings forming the Judd figure were performed. To evaluate the standalone manifestation of the filled-space illusion, we conducted experiments with distracting cross (two sets of coinciding and oppositely oriented wings) centered on the lateral terminator of the stimulus. To interpret the experimental data, we used computational procedures of previously developed quantitative models of hypothetical visual mechanisms underlying the emergence of the Müller-Lyer illusion and the filled-space illusion. It was demonstrated that theoretical calculations adequately account for the illusion magnitude variations for all modifications of stimuli, which convincingly supports the suggestion that the concomitant manifestation of the filled-space illusion is powerful enough to be considered as one of the main reasons for the asymmetric properties of illusions of extent of the Müller-Lyer type.

Invisibility concentrator based on van der Waals semiconductor α-MoO3

Abstract By combining transformation optics and van der Waals layered materials, an invisibility concentrator with a thin layer of α-MoO3 wrapping around a cylinder is proposed. It inherits the effects of invisibility and energy concentration at Fabry–Pérot resonance frequencies, with tiny scattering. Due to the natural in-plane hyperbolicity in α-MoO3, the challenges of experimental complexity and infinite dielectric constant can be resolved perfectly. Through analytical calculation and numerical simulations, the relevant functionalities including invisibility, energy concentration and illusion effect of the designed device are confirmed, which provides guidelines for the subsequent experimental verification in future.

Stepped acoustic metasurface with simultaneous modulations of phase and amplitude

Conventional acoustic metasurfaces (AMs) are limited in their ability to modulate phase and amplitude simultaneously. In this work, we analyze this limitation by using an effective medium model and propose a kind of full-control AM based on the model, which might give a more general method to build a full-control AM. The used unit is one segment of conventional space-coiling structure with adjustable height as a new degree of freedom. The metasurface can simultaneously modulate phase and amplitude for both transmitted and reflected acoustic waves. We demonstrate the abnormal refraction/reflection, acoustic focusing, and illusion effects by the metasurface.

Optimized design for illusion device by genetic algorithm

The illusion device developed from the scattering cancellation employs very simple homogeneous and isotropic materials, but this device is only valid for electrically small objects. In this paper, we prove that the illusion device optimized by genetic algorithm can be applied to large-scale occasions. For an electrically small target, an optimized core–shell illusion device can achieve better illusion effect than the analytical design based on the scattering cancellation. With the increase of the device size, the ability of the single-layered shell to manipulate the scattering is very limited. For a moderate-size target, two optimized multi-layered examples are presented: one is to make a dielectric cylinder appear as another dielectric target, and the other is to make a conducting cylinder behave like a double-negative-material target. The full-wave simulations are carried out to visualize the similar field distributions of the target and the optimized multi-layered design. This optimized design greatly widens the size application range of the illusion device and can also improve the illusion performance with simple material parameters.

Processing of the Mandarin polarity itemrenhe‘any’

AbstractThe Mandarinrenheis similar to the Englishanyin terms of polarity sensitivity (Wang 1993;Wang & Hsieh 1996;Kuo 2003;Cheng & Giannakidou 2013;Shyu 2016). However, the following phenomena regardinganyin relative clause environments have not been surveyed with respect torenhe:(a) the NPI illusion effect reported in studies like Parker & Phillips (2011;2016); (b) the subtrigging effect discussed inLeGrand (1975)and Dayal (1998;2004). We conducted two untimed, offline acceptability judgment experiments and the results suggest that: (i) NPI illusion does not appear in Mandarin in untimed offline processing, (ii) the subtrigging effect ofrenheholds, and (iii)renhecan be licensed by certain types of declarative verbs liketongyi‘agree’ andzancheng‘approve’. The results confirm the strict structural requirement of the c-commanding relation between a negation licensor andrenhe(Wang 1993) and the licensing ofrenhein non-veridical contexts (Cheng & Giannakidou 2013), and further suggest additional licensing environments forrenhe: relative clauses and declarative verbs. This requires reconsideration of positing non-veridicality as a necessary licensing condition forrenheand calls for future research on howrenheis licensed under these two licensing environments.