The Breathing Light Illusion

2017 ◽  
Author(s):  
Simone Gori ◽  
Enrico Giora ◽  
D. Alan Stubbs
Keyword(s):  
The Self ◽  
White Spot ◽  
Physical Stimulus ◽  
Black Background ◽  
Static View ◽  
Self Motion

This chapter discusses the Breathing Light Illusion. The Breathing Light Illusion is a size and brightness illusion elicited by the self-motion of the observer. The stimulus consists of a circular white spot that is presented on a black background, characterized by blurred boundaries. The blurred spot, which in static view seems to glow and exhibits a self-luminance appearance, is perceived as wider, brighter, and more diffuse when it is approached but smaller, darker, and sharper when one recedes from it. A possible explanation of the phenomenon is related to the superimposition of the afterimage on the physical stimulus during dynamical viewing.

The directions of nystagmus and apparent self-motion evoked by caloric tests and angular accelerations

2002 ◽  
Vol 11 (6) ◽  
pp. 349-355
Author(s):  
Ognyan I. Kolev
Keyword(s):  
Motion Perception ◽  
Frontal Plane ◽  
Vertical Axis ◽  
The Body ◽  
The Self ◽  
Whole Body ◽  
Caloric Stimulation ◽  
Infrared Video ◽  
Axis Rotation ◽  
Self Motion

Purpose: To further investigate the direction of (I) nystagmus and (II) self-motion perception induced by two stimuli: (a) caloric vestibular stimulations and (b) a sudden halt during vertical axis rotation. Subjects and methods: Twelve normal humans received caloric stimulation at 44°C, 30°C, and 20°C while in a supine position with the head inclined 30° upwards. In a second test they were rotated around the vertical axis with the head randomly placed in two positions: tilted 30° forward or tilted 60° backward, at a constant velocity of 90°/sec for 2 minutes and then suddenly stopped. After both tests they were asked to describe their sensations of self-motion. Eye movements were recorded with an infrared video-technique. Results: Caloric stimulation evoked only horizontal nystagmus in all subjects and induced a non-uniform complex perception of angular in frontal and transverse planes (the former dominated) and linear movements along the antero-posterior axis (sinking dominated) of the subject's coordinates. The self-motion was felt with the whole body or with a part of the body. Generally the perception evoked by cold (30°C) and warm (44°C) calorics was similar, although there were some differences. The stronger stimulus (20°C) evoked not only quantitative but also qualitative differences in perception. The abrupt halt of rotation induced self-motion perception and nystagmus only in the plane of rotation. The self-motion was felt with the whole body. Conclusion: There was no difference in the nystagmus evoked by caloric stimulation and a sudden halt of vertical axis rotation (in head positions to stimulate the horizontal canals); however, the two stimuli evoked different perceptions of self-motion. Calorics provoked the sensation of self-rotation in the frontal plane and linear motion, which did not correspond to the direction of nystagmus, as well as arcing and a reset phenomenon during angular and linear self-motion, caloric-induced self-motion can be felt predominantly or only with a part of the body, depending on the self-motion intensity. The findings indicate that, unlike the self-motion induced by sudden halt of vertical axis rotation, several mechanisms take part in generating caloric-induced self-motion.

scholarly journals Being Moved by the Self and Others: Influence of Empathy on Self-Motion Perception

PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e48293 ◽  
Author(s):  
Christophe Lopez ◽  
Caroline J. Falconer ◽  
Fred W. Mast
Keyword(s):  
Motion Perception ◽  
The Self ◽  
Self Motion ◽  
Being Moved

scholarly journals Visual self-motion feedback affects the sense of self in virtual reality

2019 ◽  
Author(s):  
Aubrieann Schettler ◽  
Ian Holstead ◽  
John Turri ◽  
Michael Barnett-Cowan
Keyword(s):  
Body Image ◽  
Virtual Reality ◽  
Visual Feedback ◽  
Sense Of Self ◽  
Body Schema ◽  
The Body ◽  
The Self ◽  
Top Down ◽  
Biological Sex ◽  
Self Motion

AbstractWe assessed how self-motion affects the visual representation of the self. We constructed a novel virtual reality experiment that systematically varied an avatar’s motion and also biological sex. Participants were presented with pairs of avatars that visually represented the participant (“self avatar”), or another person (“opposite avatar”). Avatar motion either corresponded with the participant’s motion, or was decoupled from the participant’s motion. The results show that participants identified with i) “self avatars” over “opposite avatars”, ii) avatars moving congruently with self-motion over incongruent motion, and importantly iii) identification with the “opposite avatar” over the “self avatar” when the opposite avatar’s motion was congruent with self-motion. Our results suggest that both self-motion and biological sex are relevant to the body schema and body image and that congruent bottom-up visual feedback of self-motion is particularly important for the sense of self and capable of overriding top-down self-identification factors such as biological sex.

scholarly journals Critique of Nkrumah’s Philosophical Materialism

2016 ◽  
Vol 7 (1) ◽  
pp. 1-30
Author(s):  
E I Ani
Keyword(s):  
The Self ◽  
Kwame Nkrumah ◽  
African Worldview ◽  
Self Motion

Kwame Nkrumah invokes the doctrine of emergentism in the hope of reconciling theism - a tenacious part of the African worldview - with materialism. However, in this article I seek to show that this reconciliation is not only ultimately unsuccessful, but is actually impossible. Towards this end, I identify weaknesses in what I call the six argumentative pillars of Nkrumah’s theory of emergentism (which he calls “philosophical materialism”), namely, his arguments regarding the origin of the cosmic material, the primary reality of matter, idealism, categorial convertibility, dialectic change, and the self-motion of matter. The article should provide not only alternative perspectives to Nkrumah’s metaphysics, but also highlight some broader metaphysical implications for both strong and weak emergentism. Key WordsPhilosophical materialism, consciencism, emergentism, cosmic material, categorial conversion, dialectical change, self motion of matter

Singular Assembly Configurations and Configuration Bifurcation Characteristics of the SRHGSMP

2008 ◽  
Author(s):  
Yu-Xin Wang ◽  
Yu-Tong Li ◽  
Zheng Huang ◽  
Shuang-Xia Pian
Keyword(s):  
Motion Control ◽  
Parallel Manipulator ◽  
Jacobian Matrix ◽  
Singular Points ◽  
The Self ◽  
Trajectory Design ◽  
Singularity Avoidance ◽  
Input Parameters ◽  
Matrix Correlation ◽  
Self Motion

In this paper, the configuration bifurcation characteristics at the vicinities of singular points going with different input parameters are investigated. Then, with the aid of the assembly configurations at the theoretical singular points, the reasons to cause the singularities are analyzed. We find that the dimensional-utmost singularities, line vectors correlation singularities and Jacobian matrix correlation singularities can occur individually or jointly while choosing different number of input parameters. The number and the combination form of the input parameters have great influences on the complexity of the singularities and the curvature radiuses of the configuration curves. Selecting a group of adjacent input parameters, the simple configuration bifurcation and the large singularity-free input parameters zones can be obtained. And adopting multi-input parameters, the self-motion regions and the singularity avoidance errors can be reduced. These new discoveries are valuable and of significance for the trajectory design, the singularity avoidance, and the self-motion control for the parallel manipulator, as well as the parallel tools.

On avoiding singularities in redundant robot kinematics

Robotica ◽  
1995 ◽  
Vol 13 (6) ◽  
pp. 599-606 ◽  
Author(s):  
Krzysztof Tchoń ◽  
Aleksander Matuszok
Keyword(s):  
Vector Field ◽  
Equilibrium Points ◽  
Motion Vector ◽  
Sufficient Conditions ◽  
The Self ◽  
Robot Kinematics ◽  
Redundant Robot ◽  
Singular Configurations ◽  
Motion Vector Field ◽  
Self Motion

SummaryFor redundant robot kinematics with a degree of redundancy 1 a self-motion vector field is examined whose equilibrium points lie at singular configurations of the kinematics, and whose orbits determine the self-motion manifolds. It is proved that the self-motion vector field is divergence-free. Locally, around singular configurations of corank 1, the self-motion vector field defines a 2-dimensional Hamiltonian dynamical system. An analysis of the phase portrait of this system in a neighbourhood of a singular configuration solves completely the question of avoidability or unavoidability of this configuration. Complementarily, sufficient conditions for avoidability and unavoidability are proposed in an analytic form involving the self-motion Hamilton function. The approach is illustrated with examples. A connection with normal forms of kinematics is established.

Control of the Self-Motion of a Ruthenium-Catalyzed Belousov–Zhabotinsky Droplet

2012 ◽  
Vol 116 (51) ◽  
pp. 26805-26809 ◽  
Author(s):  
Sho Kitawaki ◽  
Kazuki Shioiri ◽  
Tatsunari Sakurai ◽  
Hiroyuki Kitahata
Keyword(s):  
The Self ◽  
Self Motion
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