Scale Mechanism Design for Data Analysis in Immersive Environments

Research in spatial navigation revealed the existence of discrete strategies defined by the use of distinct reference frames during virtual path integration. The present study investigated the distribution of these navigation strategies as a function of gender, video gaming experience, and self-estimates of spatial navigation abilities in a population of 300 subjects. Participants watched videos of virtual passages through a star-field with one turn in either the horizontal (yaw) or the vertical (pitch) axis. At the end of a passage they selected one out of four homing arrows to indicate the initial starting location. To solve the task, participants could employ two discrete strategies, navigating within either an egocentric or an allocentric reference frame. The majority of valid subjects (232/260) consistently used the same strategy in more than 75% of all trials. With that approach 33.1% of all participants were classified as Turners (using an egocentric reference frame on both axes) and 46.5% as Non-turners (using an allocentric reference frame on both axes). 9.2% of all participants consistently used an egocentric reference frame in the yaw plane but an allocentric reference frame in the pitch plane (Switcher). Investigating the influence of gender on navigation strategies revealed that females predominantly used the Non-turner strategy while males used both the Turner and the Non-turner strategy with comparable probabilities. Other than expected, video gaming experience did not influence strategy use. Based on a strong quantitative basis with the sample size about an order of magnitude larger than in typical psychophysical studies these results demonstrate that most people reliably use one out of three possible navigation strategies (Turners, Non-turners, Switchers) for spatial updating and provides a sound estimate of how those strategies are distributed within the general population.

It is not clear to date how visual deprivation affects auditory spatial perception. Recent psychophysical evidences described a spatial auditory deficit in congenitally blind individuals while some others found a spatial auditory improvement. Particularly, Gori, Sandini, Martinoli, & Burr (2014) and Vercillo, Milne, Gori, & Goodale (2015) reported that people who were born blind were less efficient in localizing sound sources with respect to auditory landmarks than sighted individuals. On the other side, blind people performed similarly or even better than sighted participants during the localization of single sound sources. We investigated auditory spatial perception in early blind using different auditory spatial tasks and found that blind individuals did not succeed in localizing sound sources in an external frame of reference. The performance of early blind was severely impaired during the localization of brief auditory stimuli with respect to acoustic landmarks (allocentric frame of reference) but was comparable to that one of sighted participants when they had to localize sounds with respect to their own body (egocentric reference frame). Our results suggest that, after early visual deprivation, auditory spatial perception is centered on an egocentric reference system.

Recent psychophysical studies have described task-specific auditory spatial deficits in congenitally blind individuals. We investigated auditory spatial perception in congenitally blind children and adults during different auditory spatial tasks that required the localization of brief auditory stimuli with respect to either external acoustic landmarks (allocentric reference frame) or their own body (egocentric reference frame). Early blind participants successfully represented sound locations with respect to their body. However, they showed relative poor precision when compared to sighted participants during the localization of sound with respect to external auditory landmarks, suggesting that vision is crucial for an allocentric representation of the auditory space. In a separate study, we tested three congenitally blind individuals who used echolocation as a navigational strategy, to assess the benefit of echolocation on auditory spatial perception. Blind echolocators did not show the same impairment in auditory spatial localization reported for blind non-echolocators, but rather proved enhanced precision and accuracy as compared to blind non-echolocators and sighted participants. Our results suggest that echolocation can compensate for the spatial deficit reported in early blind individuals, likely by reactivating an allocentric reference frame needed to shape spatial representations similar to those generated by vision.

The spatial location of objects is processed in egocentric and allocentric reference frames, the early temporal dynamics of which have remained relatively unexplored. Previous experiments focused on ERP components related only to egocentric navigation. Thus, we designed a virtual reality experiment to see whether allocentric reference frame-related ERP modulations can also be registered. Participants collected reward objects at the end of the west and east alleys of a cross maze, and their ERPs to the feedback objects were measured. Participants made turn choices from either the south or the north alley randomly in each trial. In this way, we were able to discern place and response coding of object location. Behavioral results indicated a strong preference for using the allocentric reference frame and a preference for choosing the rewarded place in the next trial, suggesting that participants developed probabilistic expectations between places and rewards. We also found that the amplitude of the P1 was sensitive to the allocentric place of the reward object, independent of its value. We did not find evidence for egocentric response learning. These results show that early ERPs are sensitive to the location of objects during navigation in an allocentric reference frame.

Ray tracing is a computer graphics technique used to produce realistic visuals by physically simulating the behavior of light. Although this technique can be described straightforwardly, fully comprehending it might be challenging. It is typically taught in the classroom using the 2-D formats, such as paper or a blackboard. We propose using immersive environments for incrementing the understanding of ray tracing. We focus on improving the knowledge of the technique in experienced users, particularly Master of Computer Science students minoring in a computer-graphics-related area. We argue that exploring the ray tracing process in an immersive visualization environment can further improve the understanding of ray tracing acquired using conventional means. With that objective, this study starts by presenting <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RayTracerVR</i>, a virtual reality prototype tool for learning the mechanisms of ray tracing. This tool can be used to visually explore and interact with the different aspects of the technique. It allows users to observe the progression of the rays throughout the sequential stages of the ray tracing process and analyze its corresponding computer pseudocode. The study includes user evaluation where <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RayTracerVR</i> is employed to assess improvements in ray tracing understanding. The prototype's usability is also assessed. The findings indicate that using the ray tracing immersive learning environment results in a supplemental increase in understanding in users who have previously learned ray tracing using conventional means.

Navigating in a virtual three-dimensional maze: how do egocentric and allocentric reference frames interact?

The activity of head direction cells signals the direction of an animal's head relative to landmarks in the world. Although driven by internal estimates of head movements, head direction cells must be kept aligned to the external world by sensory inputs, which arrive in the reference frame of the sensory receptors. We present a computational model, which proposes that sensory inputs are correctly associated to head directions by virtue of a conjunctive representation of place and head directions in the retrosplenial cortex. The model allows for a stable head direction signal, even when the sensory input from nearby cues changes dramatically whenever the animal moves to a different location, and enables stable representations of head direction across connected environments.

The classic Simon effect refers to the phenomenon that responses are faster when the task-irrelevant egocentric stimulus location is on the same side as the response hand than when not. However, the spatial location of an object often varies according to which reference frame the object location was represented in, e.g., egocentric versus allocentric reference frame. It has been unknown, however, whether and how the Simon effect based on the egocentric and the allocentric reference interact, and whether the potential interaction between them is affected by task demands. To investigate these questions, we orthogonally crossed the stimulus-response compatibility induced by the egocentric and the allocentric positions during the Simon effect. Moreover, the irrelevant egocentric and allocentric positions were either explicitly represented via interleaving spatial and non-spatial tasks in Experiment 1 or not in Experiment 2. The results suggested that the Simon effect based on the egocentric locations occurred irrespective of whether the egocentric representations were explicitly coded based on current task demands or not. The Simon effect based on allocentric locations, however, seemed to occur only when the allocentric representations were explicitly induced. Moreover, the egocentric and allocentric Simon effect interacted in a similar way irrespective of task demands, with significantly delayed responses when both the egocentric and the allocentric locations were incongruent with the response code.

A Study of Object-Location Memory Hongbin Wang (Hongbin.Wang@uth.tmc.edu) Todd R. Johnson (Todd.R.Johnson@uth.tmc.edu) Jiajie Zhang (Jiajie.Zhang@uth.tmc.edu) Yue Wang (Yue.Wang@uth.tmc.edu) School of Health Information Sciences, University of Texas Health Science Center at Houston 7000 Fannin, Suite 600, Houston, TX 77030 USA Abstract This paper aims to study the representational nature of human object-location memory. Two experiments are reported, including both performance data and eye movement data. The results show that multiple allocentric frames of reference are used to encode spatial relationships among objects and late computation in object-location memory retrieval in object- cued conditions is often inevitable. The implications on developing a general model of human spatial cognition are discussed. Introduction One important aspect of human spatial memory has to do with remembering the location of objects relative to each other. For example, you might recall that the book you read last night is on your office desk between your computer and the desk lamp. This type of memory for spatial relationships is an essential component of a more general type of memory for spatial layout and is obviously critical for many spatial tasks including locating and navigation (see Tversky, 2000, for a review). It is not clear, however, how spatial relationships among objects are encoded in memory. While it seems apparent that allocentric frames of reference (i.e., locations defined relative to external objects) rather than egocentric frames of reference (i.e., locations relative to the observer self) are often used to describe these spatial relationships, the representational and computational nature of this description is controversial (see Hunt & Waller, 1999; Klatzky, 1998). For example, are object-based spatial relationships encoded and stored directly (early computation)? Or do they have to be inferred much later at the retrieval stage (late computation)? What factors determine which representational scheme is used? In this paper we report two experiments we conducted to directly address these issues. The results show that multiple allocentric frames of reference are used to encode spatial relationships among objects and late computation in object- location memory retrieval in object-cued conditions is often inevitable. This paper consists of three major parts. In the first section, the experimental paradigm is briefly introduced. In the second section, the experiments are reported, including both performance data and eye movement data. In the final section, we briefly discuss our ongoing work of developing a computational model of the object-location memory and its implications on modeling human spatial cognition in general. The Experimental Paradigm We adopted an experimental paradigm developed by Milner and colleagues in the 1990s, which we call the Milner paradigm (e.g., Johnsrude, Owen, Crane, Milner, & Evans, 1999; Milner, Johnsrude, & Crane, 1997; Owen, Milner, Petrides, & Evans, 1996). Though their focus was on neuroimaging studies of the brain foundations of object- location memory, the Milner paradigm offers an elegant experimental design that allows a systematic evaluation of multiple schema for representing spatial relationships. In addition, the availability of neuroimaging data provides invaluable constraints on both understanding behavioral results and developing computational models (e.g., Wang, Johnson, & Zhang, 2001). There are two phases in the Milner paradigm. In the encoding phase (Figure 1A), eight drawings (objects) are individually presented on a computer screen to subjects, with each drawing accompanied by two landmarks (solid squares). Subjects are asked to remember the locations of drawings, relative to the landmarks. In the retrieval phase, subjects are presented some cues plus two identical drawings. One of the two identical drawings (target) is presented in its original location, and the other one (noise) is presented in a different location (or more accurately, it occupies the original location of another object). Subjects are required to perform a forced-choice recognition of the target, relative to the cues. Milner and colleagues originally used four retrieval conditions: 1. In the fixed-landmark condition (Figure 1C), the two landmarks were presented as cues, along with the target-noise pair. The absolute location of landmarks and objects on the screen was unchanged from their original encoding positions. 2. In the shifted-landmark condition (Figure 1D), the two landmarks were presented as cues, along with the target-noise pair. Though the spatial relationships among the landmarks/drawings remained unchanged, the absolute locations of the landmarks/drawings on the screen were shifted. 3. In the fixed-object condition (Figure 1E), two encoded drawings instead the two landmarks were

Cognitive scientists increasingly use virtual reality scenarios to address spatial perception, orientation, and navigation. If based on desktops rather than mobile immersive environments, this involves a discrepancy between the physically experienced static position and the visually perceived dynamic scene, leading to cognitive challenges that users of virtual worlds may or may not be aware of. The frequently reported loss of orientation and worse performance in point-to-origin tasks relate to the difficulty of establishing a consistent reference system on an allocentric or egocentric basis. We address the verbalizability of spatial concepts relevant in this regard, along with the conscious strategies reported by participants. Behavioral and verbal data were collected using a perceptually sparse virtual tunnel scenario that has frequently been used to differentiate between humans' preferred reference systems. Surprisingly, the linguistic data we collected relate to reference system verbalizations known from the earlier literature only to a limited extent, but instead reveal complex cognitive mechanisms and strategies. Orientation in desktop virtual reality appears to pose considerable challenges, which participants react to by conceptualizing the task in individual ways that do not systematically relate to the generic concepts of egocentric and allocentric reference frames.

How robust are the deviations in haptic parallelity?

The study employs an augmented-reality App to train elementary students’ spatial rotation ability and investigates the effect of different presentation styles on students’ learning performance of spatial rotation, on their cognitive load, and on their situational interest of the training experiences. Based on the quasi-experimental design, four 5 th - and 6 th -grade classes were divided into two groups (i.e., the Augmented-Reality group and the 3D-View group) to train the spatial rotation ability. Instruments including the spatial-rotation test, the cognitive-load scale, and the situational-interest scale were used to evaluate the students’ learning performance, cognitive load, and situational interest. The two groups of students significantly improved their performance of spatial rotation after the training, and the Augmented-Reality group presented higher improvement than the 3D-View group. The two groups showed no significant difference in cognitive load no matter at the testing stage or at the training stage. Also, the two groups show no difference in their situational interest. It is suggested future research test different facets of spatial ability except the spatial rotation so more compressive spatial ability of students can be adequately evaluated. Additionally, various augmented-reality applications of different topics and areas can be developed, and different training and testing methods could be employed to understand how students learn with the assistance of the new applications.

Photorealistic 3D models (PR3DM) have great potential to supplement anatomy education; however, there is evidence that realism can increase cognitive load and negatively impact anatomy learning, particularly in students with decreased spatial ability. These differing viewpoints have resulted in difficulty in incorporating PR3DM when designing anatomy courses. To determine the effects of spatial ability on anatomy learning and reported intrinsic cognitive load using a drawing assessment, and of PR3DM versus an Artistic colour-coded 3D model (A3DM) on extraneous cognitive load and learning performance. First-year medical students participated in a cross-sectional (Study 1) and a double-blind randomised control trial (Study 2). Pre-tests analysed participants' knowledge of anatomy of the heart (Study 1, N = 50) and liver (Study 2, N = 46). In Study 1, subjects were first divided equally using a mental rotations test (MRT) into low and high spatial ability groups. Participants memorised a 2D-labeled heart valve diagram and sketched it rotated 180°, before self-reporting their intrinsic cognitive load (ICL). For Study 2, participants studied a liver PR3DM or its corresponding A3DM with texture-homogenisation, followed by a liver anatomy post-test, and reported extraneous cognitive load (ECL). All participants reported no prior anatomy experience. Participants with low spatial ability (N = 25) had significantly lower heart drawing scores (p = 0.001) than those with high spatial ability (N = 25), despite no significant differences in reported ICL (p = 0.110). Males had significantly higher MRT scores than females (p = 0.011). Participants who studied the liver A3DM (N = 22) had significantly higher post-test scores than those who studied the liver PR3DM (N = 24) (p = 0.042), despite no significant differences in reported ECL (p = 0.720). This investigation demonstrated that increased spatial ability and colour-coding of 3D models are associated with improved anatomy performance without significant increase in cognitive load. The findings are important and provide useful insight into the influence of spatial ability and photorealistic and artistic 3D models on anatomy education, and their applicability to instructional and assessment design in anatomy.

EEG correlates of spatial orientation in the human retrosplenial complex

With the rapid advancement of virtual reality technologies, understanding how human-computer interaction (HCI) affects user performance and experience has become increasingly important. This study systematically explores the impact of human-computer interaction technology in virtual reality (VR) environments on user experience. Forty-five participants conducted virtual navigation experiments, object recognition and selection tasks, and information search tasks. By analyzing statistics of eye moving–related data and subjective questionnaires from the three experiments, the study clearly indicated that different human-computer interaction patterns had a significant impact on users' task efficiency, visual cognitive load, and depth of information processing. Based on the results of the experiments, this paper presents three optimization schemes, providing specific and feasible references for future design and research in VR human-computer interaction. These findings offer valuable insights for enhancing interactive system design and promoting more effective user engagement in immersive environments. Beyond immediate design implications, the study also contributes to a broader understanding of user cognition and behavior in virtual contexts, laying the groundwork for future interdisciplinary research in education, healthcare, entertainment, and beyond.