Levels of Control During a Collaborative Carrying Task

Three experiments investigated the effect of implementing low-level aspects of motor control for a collaborative carrying task within a VE interface, leaving participants free to devote their cognitive resources to the higher-level components of the task. In the task, participants collaborated with an autonomous virtual human in an immersive virtual environment (VE) to carry an object along a predefined path. In experiment 1, participants took up to three times longer to perform the task with a conventional VE interface, in which they had to explicitly coordinate their hand and body movements, than with an interface that controlled the low-level tasks of grasping and holding onto the virtual object. Experiments 2 and 3 extended the study to include the task of carrying an object along a path that contained obstacles to movement. By allowing participants' virtual arms to stretch slightly, the interface software was able to take over some aspects of obstacle avoidance (another low-level task), and this led to further significant reductions in the time that participants took to perform the carrying task. Improvements in performance also occurred when participants used a tethered viewpoint to control their movements because they could see their immediate surroundings in the VEs. This latter finding demonstrates the superiority of a tethered view perspective to a conventional, human'seye perspective for this type of task.

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An EEG-based mind controlled virtual-human obstacle-avoidance platform in three dimensional virtual environment

2017 8th International IEEE/EMBS Conference on Neural Engineering (NER) ◽

10.1109/ner.2017.8008371 ◽

2017 ◽

Author(s):

Chunhui Zhao ◽

Zhijun Zhang ◽

Yuanqing Li ◽

Xin Pan ◽

Jun Qu ◽

...

Keyword(s):

Virtual Environment ◽

Obstacle Avoidance ◽

Three Dimensional ◽

Virtual Human

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Modified sensory feedback enhances the sense of agency during continuous body movements in virtual reality

Scientific Reports ◽

10.1038/s41598-021-82154-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kei Aoyagi ◽

Wen Wen ◽

Qi An ◽

Shunsuke Hamasaki ◽

Hiroshi Yamakawa ◽

...

Keyword(s):

Virtual Reality ◽

Motor Control ◽

Actual Body ◽

Visual Feedback ◽

Sense Of Agency ◽

Virtual Object ◽

Hand Position ◽

Body Movements ◽

Continuous Body ◽

Target Experiment

AbstractThe sense of agency refers to the feeling of control over one’s own actions, and through them, the external events. This study examined the effect of modified visual feedback on the sense of agency over one’s body movements using virtual reality in healthy individuals whose motor control was disturbed. Participants moved a virtual object using their right hand to trace a trajectory (Experiment 1) or a leading target (Experiment 2). Their motor control was disturbed by a delay in visual feedback (Experiment 1) or a 1-kg weight attached to their wrist (Experiment 2). In the offset conditions, the virtual object was presented at the median point between the desired position and the participants’ actual hand position. In both experiments, participants reported improved sense of agency in the offset condition compared to the aligned condition where the visual feedback reflected their actual body movements, despite their motion being less precise in the offset condition. The results show that sense of agency can be enhanced by modifying feedback to motor tasks according to the goal of the task, even when visual feedback is discrepant from the actual body movements. The present study sheds light on the possibility of artificially enhancing body agency to improve voluntary motor control.

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On the Determinants of Size-Constancy in a Virtual Environment

International Journal of Virtual Reality ◽

10.20870/ijvr.2009.8.1.2712 ◽

2009 ◽

Vol 8 (1) ◽

pp. 43-51 ◽

Cited By ~ 9

Author(s):

Xun Luo ◽

Robert V. Kenyon ◽

Derek G. Kamper ◽

Daniel J/ Sandin ◽

Thomas A. DeFanti

Keyword(s):

Virtual Environment ◽

Motion Parallax ◽

Physical World ◽

Virtual Object ◽

Size Constancy ◽

Visual Condition ◽

Virtual Objects ◽

Immersive Virtual Environment

An important aspect of a subject�s perception of virtual objects in a virtual environment is whether the size of the object is perceived as it would be in the physical world, which is named size-constancy. The ability of subjects to appreciate size-constancy in an immersive virtual environment was studied while scene complexity, stereovision and motion parallax visual factors were manipulated resulting in twelve different viewing conditions. Under each visual condition, 18 subjects made size judgments of a virtual object displayed at five different distances from them. Responses from the majority of our population demonstrated that scene complexity and stereovision have a significant impact on subjects' ability to appreciate size-constancy. In contrast, motion parallax produced by moving the virtual environment or by the movements of the observer alone proved not to be a significant factor in determining size-constancy performance. Consequently, size-constancy is best obtained when scene complexity and stereovision are components of the viewing conditions.

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