Effect Of Illusion Research Articles

A review of grasping as the movements of digits in space.

It is tempting to describe human reach-to-grasp movements in terms of two, more or less independent visuomotor channels, one relating hand transport to the object's location and the other relating grip aperture to the object's size. Our review of experimental work questions this framework for reasons that go beyond noting the dependence between the two channels. Both the lack of effect of size illusions on grip aperture and the finding that the variability in grip aperture does not depend on the object's size indicate that size information is not used to control grip aperture. An alternative is to describe grip formation as emerging from controlling the movements of the digits in space. Each digit's trajectory when grasping an object is remarkably similar to its trajectory when moving to tap the same position on its own. The similarity is also evident in the fast responses when the object is displaced. This review develops a new description of the speed-accuracy trade-off for multiple effectors that is applied to grasping. The most direct support for the digit-in-space framework is that prism-induced adaptation of each digit's tapping movements transfers to that digit's movements when grasping, leading to changes in grip aperture for adaptation in opposite directions for the two digits. We conclude that although grip aperture and hand transport are convenient variables to describe grasping, treating grasping as movements of the digits in space is a more suitable basis for understanding the neural control of grasping.

Attenuation of size illusion effect in dual-task conditions

We over-estimate or under-estimate the size of an object depending its background structure (e.g., the Ebbinghaus illusion). Since deciding and preparing to execute a movement is based on perception, motor performance deteriorates due to the faulty perception of information. Therefore, such cognitive process can be a source of a failure in motor performance, although we feel in control of our performance through conscious cognitive activities. If a movement execution process can avoid distraction by the illusion-deceived conscious process, the effect of the visual illusion on visuomotor performance can be eliminated or attenuated. This study investigated this hypothesis by examining two task performances developed for a target figure inducing the Ebbinghaus size illusion: showing visually perceived size of an object by index finger-thumb aperture (size-matching), and reaching out for the object and pretending to grasp it (pantomimed grasping). In these task performances, the size of the index finger-thumb aperture becomes larger or smaller than the actual size, in accordance with the illusion effect. This study examined whether the size illusion effect can be weakened or eliminated by the dual-task condition where actors’ attention to judge the object’s size and to produce the aperture size is interrupted. 16 participants performed the size-matching and pantomimed grasping tasks while simultaneously executing a choice reaction task (dual task) or without doing so (single task). Using an optical motion capture system, the size-illusion effect was analyzed in terms of the aperture size, which indicates the visually perceived object size. The illusion effect was attenuated in the dual task condition, compared to it in the single task condition. This suggests that the dual task condition modulated attention focus on the aperture movement and therefore the aperture movement was achieved with less distraction caused by illusory information.

Autism and psychosis as diametrical disorders of embodiment.

Humans have evolved an elaborate system of self-consciousness, self-identity, self-agency, and self-embodiment that is grounded in specific neurological structures including an expanded insula. Instantiation of the bodily self has been most-extensively studied via the ‘rubber hand illusion’, whereby parallel stimulation of a hidden true hand, and a viewed false hand, leads to the felt belief that the false hand is one’s own. Autism and schizophrenia have both long been regarded as conditions centrally involving altered development of the self, but they have yet to be compared directly with regard to the self and embodiment. Here, we synthesize the embodied cognition literature for these and related conditions, and describe evidence that these two sets of disorders exhibit opposite susceptibilities from typical individuals to the rubber hand illusion: reduced on the autism spectrum and increased in schizophrenia and other psychotic-affective conditions. Moreover, the opposite illusion effects are mediated by a consilient set of associated phenomena, including empathy, interoception, anorexia risk and phenotypes, and patterns of genetic correlation. Taken together, these findings: (i) support the diametric model of autism and psychotic-affective disorders, (ii) implicate the adaptive human system of self-embodiment, and its neural bases, in neurodevelopmental disorders, and suggest new therapies and (iii) experimentally ground Bayesian predictive coding models with regard to autism compared with psychosis.Lay summary: Humans have evolved a highly developed sense of self and perception of one’s own body. The ‘rubber hand illusion’ can be used to test individual variation in sense of self, relative to connection with others. We show that this illusion is reduced in autism spectrum disorders, and increased in psychotic and mood disorders. These findings have important implications for understanding and treatment of mental disorders.

연인 간 인스턴트 메시지 이용이 관계 헌신에 미치는 영향 : 사회적 실재감과 긍정적 환상의 효과를 중심으로

연인 간 인스턴트 메시지 이용이 관계 헌신에 미치는 영향 : 사회적 실재감과 긍정적 환상의 효과를 중심으로

Introduction of the Single Currency and Inflation - the Case of Central and Eastern European Countries

The study of price increases in five countries (Slovenia, Slovakia, Estonia, Latvia and Lithuania) aimed to assess the introduction of the single currency (euro) on the rate of HICP inflation in two short-term perspectives: after the first month and after the first year of the introduction of the euro in these countries. The following hypothesis was put forward: prices after the introduction of the euro are contained in the inflation target, that is, there can be no substantial increase, and contrasting views on the issue are only an effect of illusion, that is, the difference between actual and perceived inflation level. The research was carried out using the comparative method. They show that the inflation effect in the euro-adopting countries was clearly convergent with the level of price growth recorded at the same time in other European Union countries, including those already with a single currency. The result is that the reasons for excessive price growth in the short-term perspective should not be sought in connection with the introduction of the euro, but rather explained by e.g. the convergence of business cycles with these euro area countries in which HICP inflation target exceedance was recorded at the same time. There can be also any other conditions that affect price growth in all European countries, regardless of whether they belong to euro area or have its national currencies.

A Simple Target Interception Task as Test for Activities of Daily Life Performance in Older Adults.

Previous research showed that a simple target interception task reveals differences between younger adults (YA) and older adults (OA) on a large screen under laboratory conditions. Participants intercept downward moving objects while a horizontally moving background creates an illusion of the object moving in the opposite direction of the background. OA are more influenced by this illusory motion than YA. OA seem to be less able to ignore irrelevant sensory information than YA. Since sensory integration relates to the ability to perform Activities of Daily Living (ADL), this interception task can potentially signal ADL issues. Here we investigated whether the results of the target interception task could be replicated using a more portable setup, i.e., a tablet instead of a large touch screen. For YA from the same, homogeneous population, the main effects were replicated although the task was more difficult in the tablet set-up. After establishing the tablet’s validity, we analyzed the response patterns of OA that were less fit than the OA in previous research. We identified three different illusion patterns: a (large) illusion effect (indicating over integration), a reverse illusion effect, and no illusion effect. These different patterns are much more nuanced than previously reported for fit OA who only show over integration. We propose that the patterns are caused by differences in the samples of OA (OA in the current sample were older and had lower ADL scores), possibly modulated by increased task difficulty in the tablet setup. We discuss the effects of illusory background motion as a function of ADL scores using a transitional model. The first pattern commences when sensory integration capability starts to decrease, leading to a pattern of over-integration (illusion effect). The second pattern commences when compensatory mechanisms are not sufficient to counteract the effect of the background motion, leading to direction errors in the same direction as the background motion (reverse illusion). The third pattern commences when the task requirements are too high, leading OA to implement a probabilistic strategy by tapping toward the center of the screen.

Some Illusions Are More Inconsistent Than Others.

Illusions are characterized by inconsistencies. For instance, in the motion aftereffect, we see motion without an equivalent change in position. We used a simple pencil-and-paper experiment to determine whether illusions that influence an object’s apparent size give rise to equivalent changes in apparent positions along the object’s outline. We found different results for two equally strong size illusions. The Ebbinghaus illusion affected perceived positions in a way that was consistent with its influence on perceived size, but a modified diagonal illusion did not affect perceived positions. This difference between the illusions might explain why there are so many conflicting reports about the effects of size illusions on the maximum grip aperture during reach-to-grasp movements.

Multisensory integration underlying body-ownership experiences in schizophrenia and offspring of patients: a study using the rubber hand illusion paradigm

Schizophrenia is a disorder of basic self-disturbance. Evidence suggests that people with schizophrenia may have aberrant experiences of body ownership: they may feel that they are not the subject of their own body experiences. However, little is known about the development of such disturbances. Using a rubber hand illusion paradigm, we assessed body ownership in patients with schizophrenia (n = 54), healthy controls (n = 56), children/adolescents at increased familial risk of developing schizophrenia (n = 24) or mood disorders (n = 33), and children/adolescents without this risk (n = 18). In this paradigm, a rubber hand (visible) and a participant’s real hand (invisible) were stroked synchronously and asynchronously; we then measured subjective illusory experiences and proprioceptive drift. All groups showed the expected effect of the rubber hand illusion: stronger proprioceptive drift and increased subjective illusory experiences after synchronous versus asynchronous stroking. The effect of synchronicity on subjective experiences was significantly weaker in patients with schizophrenia than in healthy controls, and subjective ratings were positively correlated with delusions in patients. We found no significant differences between children/adolescents with and without increased familial risk. Large individual differences raised questions for future research. We found subtle disturbances in body-ownership experiences in patients with schizophrenia, which were associated with delusions. We found no evidence for impairments in children/adolescents at increased familial risk of developing schizophrenia or a mood disorder. Longitudinal data might reveal whether impairments in body ownership are predictive of psychosis onset.

Conformal Singularities and Topological Defects from Inverse Transformation Optics

The conventional approach to transformation optics starts with a virtual space and determines a complicated material profile in physical space, to achieve unconventional phenomena. The authors take a reverse approach, and find that the conformal singularities in the refractive-index profile are equivalent to topological defects. Optical splitting and illusion effects are confirmed. They furthermore fabricate a device with a positive topological defect, and demonstrate its light-bending functionality. Their methods could be used to connect conventional geometric optics with on-chip applications.

Characteristics of landscape evaluated from perspectives of axes in Dainaka-no-ko lagoon drained land

The objectives of this paper were to clarify characteristics of landscape in Dainaka-no-ko lagoon reclaimed land located on the coast of Lake Biwa. Based on the arrangement of roads, canals and fields constructed by the reclamation project, it was predicted and examined that the landscape centered on the axis would be viewed from the surrounding levees. Viewpoints were set at 79 points of intersection of the roads and the drainage canals with the levees. At each point, planar composition of roads, canals, fields and the other elements, situation of surrounding geography, sectional structure relating to the reclaimed land and the adjacent topography, and composition of landscape viewed from the levee were surveyed and analyzed through investigation of both literature materials and maps and field work. As a result, the characteristics that the axis of the road or the drainage canal was at the center, and the fields were lined up on both sides were clarified. Such character of line symmetrical landscape along the axis was weakened by buildings and other elements. Gradient changes that caused the optical illusion effect pointed out in the research of the French garden was also seen in this reclaimed land. It also turned out that there were possibilities of improving the value of such landscape by introducing the landscape design which took advantage of the axes.

The Uznadze illusion reveals similar effects of relative size on perception and action.

Milner and Goodale (the visual brain in action, Oxford University Press Inc., Oxford, 1995) proposed a functional dissociation between vision-for-action and vision-for-perception (i.e., the "two-visual system hypothesis", TVSH). Supporting the TVSH, it has been claimed that visual illusions affect perception but not actions. However, at least for the Ebbinghaus illusion, numerous studies have revealed consistent illusion effects on grasping. Thus, whether illusions affect actions remains controversial. To further investigate the dissociation predicted by the TVSH, we used a visual version of the Uznadze illusion (the same stimulus will feel smaller after feeling a larger stimulus and larger after feeling a smaller stimulus). Based on kinematic recordings of finger aperture in a motor (precision grip) and a perceptual task (manual estimation), we report two main findings. First, both action and perception are strongly affected by the Uznadze illusion. Second, the illusion decreases similarly in both tasks when inducing-induced pairs had different shape and color, in comparison to the equivalent condition where these features are the same. These results are inconsistent with a perception-action dissociation as predicted by the TVSH and suggest that, at least in the present conditions, vision-for-perception and vision-for-action are similarly affected by contextual cues.

Ventriloquist Illusion Produced With Virtual Acoustic Spatial Cues and Asynchronous Audiovisual Stimuli in Both Young and Older Individuals.

Ventriloquist illusion, the change in perceived location of an auditory stimulus when a synchronously presented but spatially discordant visual stimulus is added, has been previously shown in young healthy populations to be a robust paradigm that mainly relies on automatic processes. Here, we propose ventriloquist illusion as a potential simple test to assess audiovisual (AV) integration in young and older individuals. We used a modified version of the illusion paradigm that was adaptive, nearly bias-free, relied on binaural stimulus representation using generic head-related transfer functions (HRTFs) instead of multiple loudspeakers, and tested with synchronous and asynchronous presentation of AV stimuli (both tone and speech). The minimum audible angle (MAA), the smallest perceptible difference in angle between two sound sources, was compared with or without the visual stimuli in young and older adults with no or minimal sensory deficits. The illusion effect, measured by means of MAAs implemented with HRTFs, was observed with both synchronous and asynchronous visual stimulus, but only with tone and not speech stimulus. The patterns were similar between young and older individuals, indicating the versatility of the modified ventriloquist illusion paradigm.

Modeling optimizes the effect of the vertical stripe illusion for foot clearance on upstairs

Modeling optimizes the effect of the vertical stripe illusion for foot clearance on upstairs

Does Money Illusion Delude Investors?

This study investigates the role of money illusion in a broad set of anomaly-based strategies. To the extent that anomalies reflect mispricing, I examine whether money illusion predicts anomaly returns. I find that, following periods of high inflation, anomalies are stronger and returns in short leg portfolios are lower. However, following periods of deflation, returns in short leg portfolios are not lower and long-short strategies are not profitable. These findings indicate that money-illusioned investors excessively extrapolate the upside potential of stocks in short leg portfolios following periods of high inflation and, subsequently, experience negative returns. I find the effect of money illusion to remain largely unchanged after controlling for sentiment. Overall, this study presents evidence that money illusion leads to mispricing in the stock market.

The effect of kinesthetic illusion induced by visual stimulation of ankle joint on motor imagery

The effect of kinesthetic illusion induced by visual stimulation of ankle joint on motor imagery

Development of Vibrotactile Pedestal With Multiple Actuators and Application of Haptic Illusions for Information Delivery

In this study, a vibrotactile pedestal with multiple actuators is developed and applied to smartphones to create a sense of information according to location and direction. As the main goal is to create a detailed sensation with a limited number of actuators, well-known sensory illusion effects are utilized to modulate vibrotactile stimuli to create an appropriate sensation. The monolithic design concept is utilized to the touch surface of the pedestal for a smooth grip so that there is no interference with screen interaction of the smartphone. Two experiments were conducted to validate whether the developed device could successfully reproduce directional and locational information according to given visual data. The results show that vibrotactile stimulation from the pedestal was useful in intuitively displaying information such as position and direction for smartphone applications. The implications of the work presented in this paper can serve as a stepping stone toward the development of smartphone applications with affluent sensory information through vibrotactile stimulation.

Entropy Analysis on Planar Anamorphic Images

Abstract Anamorphosis is an art of drawing, which creates illusion effect over the drawn image plane, and the impact of the illusion is nullified when the specific viewing position is used to view the drawn image. In digital imaging domain, the effect of anamorphosis is analyzed quantitatively by the amount of distortion present in the anamorphized image. This study on the anamorphized image suggested that the optimal combination of parameters can create the better-anamorphized image.

Effect of kinesthetic illusion induced by visual stimulation on ankle dorsiflexion dysfunction in a stroke patient: ABAB single-case design

ABSTRACTThe purpose of this study was to investigate the effect of simultaneous intervention with the kinesthetic illusion induced by visual stimulation (KiNvis) and voluntary exercise on ankle dorsiflexion dysfunction in a patient with right-sided stroke hemiparesis. Within an ABAB single-case design, we conducted two phases each lasting five days. Phase A represented the baseline during which only voluntary ankle dorsiflexion (VAD) was performed. Phase B involved simultaneous performance of VAD and KiNvis. We measured the angle of ankle joint dorsiflexion (AJD), and the 10 m maximum walking speed (10MWS). AJD and 10MWS were significantly improved in phase B.

Illusion effect and expansion possibility of modern glass art

Illusion effect and expansion possibility of modern glass art

Does Value Creation Drives Growth Illusion? An Evidence from Indonesia Stock Exchange

The main aim of this study is to explore the illusion effect on the growth market of firm value, and to examine the value creation of manufacturing companies listed in the Indonesia Stock Exchange (IDX).The study used pooled data of the manufacturing companies listed in the Indonesia Stock Exchange (IDX), and estimated the overvaluation using the model developed by Rhodes-Kropf, Robinson, and Viswanathan (2005). The real earnings management, based on overproduction and auditing, results on an increase in the valuation. However, the value of creating actions of the firms in the form of accrual management and real earnings management based on discretionary expense are less likely to significantly contribute to shape the overvaluation.The findings are helpful for regulators to improve supervision to real earnings management based on overproduction and the use of the Big Four auditors to prevent any potential value creation that leads to misvaluation in the market, as well as for professionals, investors and analysts to evaluate the quality of accounting numbers, select a portfolio of stocks, and make lending decisions.Unlike any previous studies highlighting the consequences of overvaluation and focusing on predicting the occurrence of overvaluation as a result of earnings management practices, this study mainly focuses on the earnings management as the cause of the overvaluation in the form of variables of accrual management and real earnings management based on discretionary expenses and overproduction.