不连续虚拟现实空间中的再定向

虚拟空间的特点之一是具有不连续性, 即在无连接型建筑单元的情况下各个单体间可直接通达的特性。本研究对人在不连续的虚拟空间中的再定向能力进行了探究, 将人类空间再定向能力的研究从现实空间延伸到了虚拟空间, 并研究了人在不同虚拟现实设备中的行为表现差异。结果表明, 人在不连续的虚拟空间中能完成再定向任务, 而虚拟空间中建筑单元的几何信息对人在不连续虚拟空间中的再定向表现无显著影响, 但被试在桌面式虚拟现实中的成绩显著高于在头盔式虚拟现实中的成绩。这些结果表明了人对不连续的虚拟空间的适应性。     

Disorientation inhibits landmark use in 12-18-month-old infants

Recent research has indicated that, particularly under conditions of inertial disorientation, mammals may be sensitive to landmark configuration geometry at the expense of individual featural information when locating hidden goals. The current study sought to establish whether landmark use could be demonstrated in 12-18-month-old infants with and without a disorientation procedure, and with geometrically ambiguous landmark configurations. A peekaboo paradigm was employed in which infants learned to anticipate a peekaboo event after a cue from two locations within a circular arena, followed by a test trial from a novel position in which no peekaboo occurred after the cue. In all conditions, an isosceles triangle arrangement of landmarks was used, with peekaboo occurring between the landmarks of one of the two equal "sides", thus being geometrically ambiguous. In two conditions, the landmarks were distinctive, and in two further conditions, they were identical. In one of the distinctive conditions and one of the identical landmark conditions, infants underwent a disorientation procedure in between training and test trials. Only oriented infants with distinctive landmarks were successful in test trials, thus suggesting that infants are able to use the individual features of landmarks to locate a goal, but can only do so if oriented.     

Restorative effects of virtual nature settings

Previous research regarding the potential benefits of exposing individuals to surrogate nature (photographs and videos) has found that such immersion results in restorative effects such as increased positive affect, decreased negative affect, and decreased stress. In the current experiment, we examined whether immersion in a virtual computer-generated nature setting could produce restorative effects. Twenty-two participants were equally divided between two conditions, while controlling for gender. In each condition, participants performed a stress-induction task, and were then immersed in virtual reality (VR) for 10 minutes. The control condition featured a slide show in VR, and the nature experimental condition featured an active exploration of a virtual forest. Participants in the nature condition were found to exhibit increased positive affect and decreased stress after immersion in VR when compared to those in the control condition. The results suggest that immersion in virtual nature settings has similar beneficial effects as exposure to surrogate nature. These results also suggest that VR can be used as a tool to study and understand restorative effects.     

路标信息在幼儿空间再定向中的作用

以往研究表明幼儿不能有效地整合利用路标等非几何信息,主要依赖几何信息进行再定向。即使能利用路标信息,也只是建立了靶物体与路标之间的直接联结,而不是用于空间再定向。本研究在矩形房间的四角设置颜色不同的档板作为路标线索,以平均年龄为3.5岁的幼儿为被试,结果发现,在几何信息与路标信息同时存在的情形下,幼儿可以整合利用空间中的几何信息与路标信息;即使只有路标信息,幼儿也能依赖路标信息结合左右方位感准确地再定向,这些结果表明幼儿能够充分利用空间中的路标信息以重新确定自己的方位。     

Virtual environment training system for rehabilitation of stroke patients with unilateral neglect: crossing the virtual street.

In this paper, we propose a system for training of stroke patients with unilateral neglect by using technology of virtual reality (VR). The proposed system is designed to compensate for unilateral neglect. This system contains the calibration of unilateral neglect and the training of this disease. The calibration procedure is implemented by aligning the virtual object at a subjective middle line. The training procedure is implemented by completing the missions that are used to keep the virtual avatar safe during crossing the street in a virtual environment. The results of this study show that the proposed system is effective to train unilateral neglect. The left to right ratio scores extracted from this system gradually decrease as the sessions of training are repeated. To validate the VR system parameters, the parameters are analyzed by correlation with those of traditional unilateral neglect assessment methods (such as the line bisection test and the cancellation test).     

Landmark Stability: Further Studies Pointing to a Role in Spatial Learning

Two experiments were conducted to investigate the possible role of landmark stability in spatial learning. Rats were trained to search in a large arena for food hidden at a consistent distance and direction from either a single radially symmetric landmark or an array of two landmarks. We varied the relative degree to which the landmark array and/or the cues of the training context predicted the location of food, without varying the conditional probability of food being available given either cue. Experiment 1 used vestibular disorientation to ensure control of search location by experimenter-controlled cues. The results showed that making either a single landmark or a cluster of two adjacent landmarks the sole spatial predictor of reward location reduced the accuracy of search compared to a condition where both the landmark array and context cues were reliable spatial predictors. Varying global landmark stability had no effect when training was conducted using an array of two landmarks located some distance from each other. Context cues, when tested alone, triggered very little searching in appropriate locations, and the absolute magnitude of control over search was insufficient to account for the superiority of stable landmarks. The better learning with a stable landmark, and the dependence of this effect on the geometrical arrangement of landmarks, points to the conditions of spatial learning involving additional principles to those of simple associative conditioning. Experiment 2 examined landmark stability using a single landmark and fixed directional cues in the absence of vestibular disorientation. This also revealed a relative advantage of landmark stability, but animals with a landmark that moved from trial to trial did show some evidence of learning. Context cues when tested alone had minimal influence. Parametric manipulation of landmark stability offers a novel way of influencing spatial learning and thus understanding better the process through which egocentric representations of perceived space are transformed into allocentric representations of the real world. The purpose of this paper is to describe two experiments concerned with identifying the psychological processes of allocentric spatial learning. The results point to the idea that landmark stability is an important factor in spatial learning. Specifically, they reveal that whether or not a landmark will be used for the purpose of representing the location of another object (including hidden objects) is influenced by whether it is perceived as geometrically stable with respect to at least one other landmark and/or certain geometric features of the environment. This phenomenon is relevant to the application of associative learning principles to the spatial domain.     

Reaching within video-capture virtual reality: using virtual reality as a motor control paradigm.

We have developed a virtual reality (VR) system that integrates a three-dimensional tracking device with a video-capture VR platform to record upper limb movements. The influence of target velocity on planning and execution of reaching movements was studied in five healthy subjects. Our initial results suggest that a target's velocity is considered when planning an interceptive action and that a hand reaching toward a moving virtual target is controlled in a similar way to how it is in the real visual environment.     

Pain modulation during drives through cold and hot virtual environments.

Evidence exists that virtual worlds reduce pain perception by providing distraction. However, there is no experimental study to show that the type of world used in virtual reality (VR) distraction influences pain perception. Therefore, we investigated whether pain triggered by heat or cold stimuli is modulated by "warm "or "cold " virtual environments and whether virtual worlds reduce pain perception more than does static picture presentation. We expected that cold worlds would reduce pain perception from heat stimuli, while warm environments would reduce pain perception from cold stimuli. Additionally, both virtual worlds should reduce pain perception in general. Heat and cold pain stimuli thresholds were assessed outside VR in 48 volunteers in a balanced crossover design. Participants completed three 4-minute assessment periods: virtual "walks " through (1) a winter and (2) an autumn landscape and static exposure to (3) a neutral landscape. During each period, five heat stimuli or three cold stimuli were delivered via a thermode on the participant's arm, and affective and sensory pain perceptions were rated. Then the thermode was changed to the other arm, and the procedure was repeated with the opposite pain stimuli (heat or cold). We found that both warm and cold virtual environments reduced pain intensity and unpleasantness for heat and cold pain stimuli when compared to the control condition. Since participants wore a head-mounted display (HMD) in both the control condition and VR, we concluded that the distracting value of virtual environments is not explained solely by excluding perception of the real world. Although VR reduced pain unpleasantness, we found no difference in efficacy between the types of virtual world used for each pain stimulus.     

儿童空间再定向能力发展的理论之争

空间再定向是指迷失方向的个体在空间中重新确定自己方位并找回迷失方向前丢失或被隐藏物体的能力.几何模块理论、适应性结合理论和视觉图像匹配理论都能够对儿童空间再定向做出一定解释,但三者之间互不相容,并存在局限:解释不了语言对整合几何和非几何信息的影响、环境空间大小和参照系选择对再定向的影响以及空间再定向中性别差异的现象.今后研究应注意实验的生态效应、空间条件的规则性、几何信息的直接性与间接性以及对三个理论的整合.     

Effectiveness of virtual reality distraction during a painful medical procedure in pediatric oncology patients

The effectiveness of virtual reality (VR) as a behavioral intervention designed to decrease distress during port access procedure was examined in 20 7- to 14-year-old pediatric oncology patients. Children were randomized to either engage in an immersive VR environment during the procedure or to a no VR control condition. Children's distress was assessed through subjective self-ratings and objective physiological and behavioral ratings. Narrative accounts of the experience were used as a measure of how well the child coped with the procedure. VR was effective in reducing children's distress on all measures. Implications of these findings for intervention are discussed.     

Spatial reorientation: the effects of space size on the encoding of landmark and geometry information

The effects of the size of the environment on animals’ spatial reorientation was investigated. Domestic chicks were trained to find food in a corner of either a small or a large rectangular enclosure. A distinctive panel was located at each of the four corners of the enclosures. After removal of the panels, chicks tested in the small enclosure showed better retention of geometrical information than chicks tested in the large enclosure. In contrast, after changing the enclosure from a rectangular-shaped to a square-shaped one, chicks tested in the large enclosure showed better retention of landmark (panels) information than chicks tested in the small enclosure. No differences in the encoding of the overall arrangement of landmarks were apparent when chicks were tested for generalisation in an enclosure differing from that of training in size together with a transformation (affine transformation) that altered the geometric relations between the target and the shape of the environment. These findings suggest that primacy of geometric or landmark information in reorientation tasks depends on the size of the experimental space, likely reflecting a preferential use of the most reliable source of information available during visual exploration of the environment.     

几何模块论的局限性——来自梯形实验的证据

以往研究表明幼儿主要依赖几何信息进行再定向,但这些研究大多使用矩形空间。在本研究中,幼儿所处的空间为几何信息更丰富,目标物体所在位置确定的梯形。结果发现,幼儿并不会利用新增的几何信息确定目标物体,仍然去正确位置的对角寻找,表现出的寻找模式与矩形空间一样,这说明幼儿在空间再定向任务中对几何信息的利用很有限。此外,录像分析的结果发现,幼儿在面向梯形两底边时会更多地且径直地走向正确位置或对角,这种寻找过程上的特点表明他们可能基于空间轴朝向结合左右方位感表征物体位置     

The impact of virtual reality functions of a hotel website on travel anxiety.

This study deals with the impact of virtual reality (VR) features that are embedded in a hotel website on travelers' anxiety. Having more information is thought to be a factor in relieving anxiety in travel. A hotel website can be a good place for gathering information about the accommodation. In this study, we posit that a hotel website with VR functions should lead to a reduction in travelers' anxiety about travel. We built a website of a hotel and used VR functions to show the exterior, the lobby, a guest room, and a restaurant through an interactive and spatial shot of the hotel images. The experiment was conducted with a premise that the subjects were about to embark on a journey to an unknown place and to stay at an unknown hotel whose website contained VR functions. The subjects were asked to play with VR functions of the hotel website and then to complete a survey with questions regarding the degree of anxiety on the travel and psychological relief that might have been perceived by the subjects. The result confirms our hypothesis that there is a statistically significant relationship between the degree of travel anxiety and psychological relief caused by the use of VR functions of a hotel website.     

Blocking of spatial learning between enclosure geometry and a local landmark

In a virtual environment, blocking of spatial learning to locate an invisible target was found reciprocally between a distinctively shaped enclosure and a local landmark within its walls. The blocking effect was significantly stronger when the shape of the enclosure rather than the landmark served as the blocking cue. However, the extent to which the landmark blocked enclosure-shape learning was not influenced by increasing the physical salience of the landmark. The outcomes are the first to suggest that cue-interaction effects, commonly found in human and animal contingency learning experiments, are also found in human spatial learning based on landmarks and enclosure walls. The data are discussed in terms of spatial reference frames.     

Penetrating the geometric module: catalyzing children's use of landmarks

We used a reference memory paradigm to examine whether 4- and 5-year-old children could be trained to use landmark features to relocate targets after disorientation. In Experiment 1, half of the children were pretrained in a small equilateral triangle-shaped room. Each of the three walls was a different color, and the target was always in the middle of the yellow wall. These children and a control group were tested in a small rectangular room with three white walls and one yellow wall; the target was placed in one of the corners. Children with pretraining responded more frequently to the correct corner than to the diagonally congruent corner on their first set of four trials in the rectangular room, whereas the children in the control group used geometric cues exclusively. Three additional groups of children (Experiment 2) showed that the use of landmark features--both salient and subtle--can be learned in as few as four practice trials in a small rectangular room. The data support the view that both geometry and landmark features are adaptively combined in the same representation.     

Use of virtual reality distraction to reduce claustrophobia symptoms during a mock magnetic resonance imaging brain scan: a case report.

The present case series with two patients explored whether virtual reality (VR) distraction could reduce claustrophobia symptoms during a mock magnetic resonance imaging (MRI) brain scan. Two patients who met DSM-IV criteria for specific phobia, situational type (i.e., claustrophobia) reported high levels of anxiety during a mock 10-min MRI procedure with no VR, and asked to terminate the scan early. The patients were randomly assigned to receive either VR or music distraction for their second scan attempt. When immersed in an illusory three-dimensional (3D) virtual world named SnowWorld, patient 1 was able to complete a 10-min mock scan with low anxiety and reported an increase in self-efficacy afterwards. Patient 2 received "music only" distraction during her second scan but was still not able to complete a 10-min scan and asked to terminate her second scan early. These results suggest that immersive VR may prove effective at temporarily reducing claustrophobia symptoms during MRI scans and music may prove less effective.     

The use of virtual environments for survey spatial ability evaluation in topographical disorientation

Due to their interactivity and to the sense of presence they afford, virtual environments constitute an interesting opportunity to study spatial cognition. In accordance with this perspective, we aimed to introduce a spatial test in virtual simulation in order to investigate the survey spatial ability in patients with topographical disorientation. To do this, we used the "planning in advance task" in a virtual environment that constitutes an effective procedure to experimentally evaluate survey maps. With this procedure we present the single case of a woman, with a right medial temporal lobe lesion, who shows a selective impairment in the acquisition of new spatial relationships. The patient's performance in "planning in advance task" was compared with that of a control group made up of 40 female subjects matched for age and education. Results show how the patient revealed a significantly lower spatial performance when compared to the control group, demonstrating an inability to solve survey-type spatial tasks in complex virtual environments.     

Affective interactions using virtual reality: the link between presence and emotions.

Many studies showed the ability of movies and imagery techniques to elicit emotions. Nevertheless, it is less clear how to manipulate the content of interactive media to induce specific emotional responses. In particular, this is true for the emerging medium virtual reality (VR), whose main feature is the ability to induce a feeling of "presence" in the computer-generated world experienced by the user. The main goal of this study was to analyze the possible use of VR as an affective medium. Within this general goal, the study also analyzed the relationship between presence and emotions. The results confirmed the efficacy of VR as affective medium: the interaction with "anxious" and "relaxing" virtual environments produced anxiety and relaxation. The data also showed a circular interaction between presence and emotions: on one side, the feeling of presence was greater in the "emotional" environments; on the other side, the emotional state was influenced by the level of presence. The significance of these results for the assessment of affective interaction is discussed.     

How do young children determine location? Evidence from disorientation tasks

Previous studies show that following disorientation children use the geometry of an enclosed space to locate an object hidden in one of the corners [e.g. (Hermer, L., & Spelke, E. (1996). Modularity and development: A case of spatial reorientation. Cognition, 61, 195-232)]. These studies have used a disorientation procedure that involves rotating the viewer (with eyes closed). Here, we examine 18- to 25-month-olds' spatial coding in two disorientation tasks--involving either viewer or space rotation. Importantly, the rotational movements in both tasks could not be visually tracked. Children were tested in either task (viewer- or space-movement) from either inside or outside a triangular (isosceles) space (with one unique and two equivalent corners). In the viewer-movement task, performance was above chance, regardless of which corner contained the object. In the space-movement task, performance was above chance at only the unique corner. On both tasks, performance was better from inside the space than from outside. The implications for how children determine location are discussed.