7. Shape and Motion Integration in People Perception Depends on the Action of the Performer

2018 ◽  
Author(s):  
Claire Honda
Keyword(s):  
Visual Information ◽  
Body Shape ◽  
Object Perception ◽  
Human Action ◽  
The Body ◽  
Motion Information ◽  
Centre Of Mass ◽  
Indirect Object ◽  
Throw Distance

Perception of human action depends on both the body shape and motion of a performer. We can indirectly perceive the properties of an object being acted upon even when visual information is limited and the object itself is not visible; we accomplish this using internal models of a body’s dynamics and an action’s kinematics (Runeson & Frykholm, 1981). We are also sensitive to correlations between a performer’s shape and motion, known as internal consistency (Runeson & Frykholm, 1983). To investigate how decorrelating shape and motion affects indirect object perception, we ran an experiment where participants watched realistic avatars of performers manipulating invisible objects. Unbeknownst to participants, half of the stimuli were internally inconsistent: the shape of one performer was combined with the motion of a performer with a dissimilar body shape. Participants saw sled pushes, beanbag throws, and box lifts, and estimated the sled weight, throw distance, or box weight. For sled pushes, there was a shape-motion interaction such that heavy bodies were perceived as pushing heavier weights when animated with motion from light performers, and light bodies were perceived as pushing lighter weights when animated with motion from heavy performers. In contrast, participants estimated beanbag throw distance primarily from performer motion. Interpretation of the box lift data is more complex. In conclusion, the way in which our visual system combines shape and motion information depends on the role of body shape and centre of mass on the outcome of an action.

scholarly journals Men, appearance, and cosmetic surgery: The role of confidence, self-esteem, and comfort with the body

2008 ◽  
Vol 34 (1) ◽  
pp. 105-134 ◽  
Author(s):  
Rosemary Ricciardelli ◽  
Kimberley Ann Clow
Keyword(s):  
Cosmetic Surgery ◽  
Body Shape ◽  
Online Survey ◽  
Identity Theory ◽  
Self Esteem ◽  
The Body ◽  
Sociology Of The Body ◽  
Lower Confidence

Recent research has suggested that perceptions of the body are important to men’s sense of confidence and that men see the body as a vehicle for personal improvement. To build on this research, an online survey investigated Canadian men’s perspectives on their appearance and their attitudes toward cosmetic surgery. Low self-esteem, lack of confidence, and comfort with one’s body uniquely predicted different aspects of men’s experiences, including attitudes about body shape, perceptions of others, pressures to lose weight, and perspectives regarding cosmetic surgery. For example, participants who were more comfortable with their bodies and higher in self-esteem were happier with their current body shape and features, whereas participants who were less comfortable with their bodies and lower in confidence put more pressure on themselves to lose weight. In addition, lower confidence significantly predicted willingness to undergo cosmetic surgery. Men’s perspectives on cosmetic surgery were thematically analyzed. These findings are situated within identity theory and sociology of the body.

Oscillatory motion and wake instability of freely rising axisymmetric bodies

2007 ◽  
Vol 573 ◽  
pp. 479-502 ◽  
Author(s):  
PEDRO C. FERNANDES ◽  
FRÉDÉRIC RISSO ◽  
PATRICIA ERN ◽  
JACQUES MAGNAUDET
Keyword(s):  
Reynolds Number ◽  
Aspect Ratio ◽  
Axial Velocity ◽  
Body Shape ◽  
Rigid Bodies ◽  
The Body ◽  
Body Motion ◽  
Wake Instability ◽  
Moving Bodies

This paper reports on an experimental study of the motion of freely rising axisym- metric rigid bodies in a low-viscosity fluid. We consider flat cylinders with height h smaller than the diameter d and density ρb close to the density ρf of the fluid. We have investigated the role of the Reynolds number based on the mean rise velocity um in the range 80 ≤ Re = umd/ν ≤ 330 and that of the aspect ratio in the range 1.5 ≤ χ = d/h ≤ 20. Beyond a critical Reynolds number, Rec, which depends on the aspect ratio, both the body velocity and the orientation start to oscillate periodically. The body motion is observed to be essentially two-dimensional. Its description is particularly simple in the coordinate system rotating with the body and having its origin fixed in the laboratory; the axial velocity is then found to be constant whereas the rotation and the lateral velocity are described well by two harmonic functions of time having the same angular frequency, ω. In parallel, direct numerical simulations of the flow around fixed bodies were carried out. They allowed us to determine (i) the threshold, Recf1(χ), of the primary regular bifurcation that causes the breaking of the axial symmetry of the wake as well as (ii) the threshold, Recf2(χ), and frequency, ωf, of the secondary Hopf bifurcation leading to wake oscillations. As χ increases, i.e. the body becomes thinner, the critical Reynolds numbers, Recf1 and Recf2, decrease. Introducing a Reynolds number Re* based on the velocity in the recirculating wake makes it possible to obtain thresholds $\hbox{\it Re}^*_{cf1}$ and $\hbox{\it Re}^*_{cf2}$ that are independent of χ. Comparison with fixed bodies allowed us to clarify the role of the body shape. The oscillations of thick moving bodies (χ < 6) are essentially triggered by the wake instability observed for a fixed body: Rec(χ) is equal to Recf1(χ) and ω is close to ωf. However, in the range 6 ≤ χ ≤ 10 the flow corrections induced by the translation and rotation of freely moving bodies are found to be able to delay the onset of wake oscillations, causing Rec to increase strongly with χ. An analysis of the evolution of the parameters characterizing the motion in the rotating frame reveals that the constant axial velocity scales with the gravitational velocity based on the body thickness, $\sqrt{((\rho_f-\rho_b)/\rho_f)\,gh}$, while the relevant length and velocity scales for the oscillations are the body diameter d and the gravitational velocity based on d, $\sqrt{((\rho_f-\rho_b)/\rho_f)\,gd}$, respectively. Using this scaling, the dimensionless amplitudes and frequency of the body's oscillations are found to depend only on the modified Reynolds number, Re*; they no longer depend on the body shape.

scholarly journals Free motion of a body in a boundary layer or channel flow

2017 ◽  
Vol 813 ◽  
pp. 279-300 ◽  
Author(s):  
Frank T. Smith
Keyword(s):  
Boundary Layer ◽  
Channel Flow ◽  
Body Shape ◽  
Lateral Position ◽  
The Body ◽  
Centre Of Mass ◽  
Pressure Force ◽  
The Core ◽  
Moving Body ◽  
Freely Moving

Coupling is considered between fluid flow and a freely moving body shorter than the development length in an oncoming boundary layer or channel flow but longer than the flow thickness. The body lies within the core of the flow. The coupling occurs between the inviscid-dominated displacement and the viscous–inviscid pressure, the latter acting to move the body. This interaction can be unstable. It is found however that three factors serve to stabilise the interaction as each one alters the decisive balance of angular momentum. One is a 10 % shift forward in the position of the centre of mass. The second is a degree of flexibility in the body shape by means of its response to the induced pressure force. Third is a slight streamwise movement of the body which is sufficient to modify the viscous–inviscid pressure response and again produce stabilisation. The effects are largely independent of the lateral position of the body.

Evidence of a heritable component to body shape in the northern redbelly dace (Phoxinus eos)

1997 ◽  
Vol 75 (8) ◽  
pp. 1247-1253 ◽  
Author(s):  
C. Anna Toline ◽  
Allan J. Baker
Keyword(s):  
Body Shape ◽  
Natural Populations ◽  
The Body ◽  
Foraging Ability ◽  
Environmental Induction ◽  
Foraging Tactics ◽  
Selection For ◽  
Shape Changes ◽  
Common Laboratory

Hypotheses about the role of selection on body-shape evolution assume a heritable component to this phenotypic character. To examine the influence of environmental induction on body shape, offspring form two morphologically differentiated populations of northern redbelly dace (Phoxinus eos) were reared in a common laboratory environment. Additionally, shape changes were monitored over 3 consecutive years in six populations. Offspring reared in a common environment retained the body shape of individuals from their natal pond, and shape changes among fish in different ponds were maintained in natural populations over years. These results strongly suggest a heritable component to body shape in P. eos. These results complement earlier work examining foraging tactics as a potential selection pressure on body shape and support the conclusion that body-shape differences among fish in different ponds are being maintained by selection for foraging ability.

scholarly journals The (re)production of climbing space: bodies, gestures, texts

2016 ◽  
Vol 24 (1) ◽  
pp. 69-88 ◽  
Author(s):  
Jillian M Rickly
Keyword(s):  
Human Action ◽  
Rock Climbing ◽  
The Body ◽  
Production Of Space ◽  
Rock Face ◽  
Textual Representations ◽  
Sport Climbing ◽  
Starting Point ◽  
Representations Of Space

According to Lefebvre, space is not an absolute given, an empty and presumed starting point, but space is produced through human action. Furthermore, he contends, there is a material basis to the production of space – the ‘practical and fleshy body’. The body must be conceived as both active in the production of space and produced by space, and thereby subject to the determinants of that space. This article demonstrates the crucial role of the body in Lefebvre’s trialectic as it interrogates the embodied mobile practice of rock climbing, specifically sport climbing. First, it begins with an examination of the role of climbing bodies in the production of climbing space; put into practice by the perceived space of the rock, bodies shape and are shaped by this interaction. Second, it investigates the mechanisms that continue the production of climbing space off the rock face, as climbers communicate with practice-specific gestures and jargon. Third, it approaches climbing landscapes as texts, focusing on the production of representations of space as routes are inscribed on rock faces, transcribed into guidebooks and websites, and circulated among climbing media. Finally, considering landscape as a way of seeing forces the investigation to return, full-circle, to situate the ways bodies enact landscapes in relation to textual representations of space. As such, this article explores the relationality of individual climbing bodies, rock climbing communities, and climbing media in the (re)production of climbing space to demonstrate the complementarity of landscape–body and landscape-as-text perspectives in the social production of space.

scholarly journals Data-driven geometric system identification for shape-underactuated dissipative systems

2021 ◽  
Author(s):  
Brian Arthur Bittner ◽  
Ross L Hatton ◽  
Shai Revzen
Keyword(s):  
System Identification ◽  
Body Shape ◽  
The Body ◽  
System Model ◽  
Data Driven ◽  
Model Complexity ◽  
Dissipative Systems ◽  
Pneumatic Actuators ◽  
Series Elastic Actuators

Abstract Systems whose movement is highly dissipative provide an opportunity to both identify models easily and quickly optimize motions. Geometric mechanics provides means for reduction of the dynamics by environmental homogeneity, while the dissipative nature minimizes the role of second order (inertial) features in the dynamics. Here we extend the tools of geometric system identification to ``Shape-Underactuated Dissipative Systems (SUDS)'' -- systems whose motions are more dissipative than inertial, but whose actuation is restricted to a subset of the body shape coordinates. Many animal motions are SUDS, including micro-swimmers such as nematodes and flagellated bacteria, and granular locomotors such as snakes and lizards. Many soft robots are also SUDS, particularly those robots using highly damped series elastic actuators. Whether involved in locomotion or manipulation, these robots are often used to interface less rigidly with the environment. We motivate the use of SUDS models, and validate their ability to predict motion of a variety of simulated viscous swimming platforms. For a large class of SUDS, we show how the shape velocity actuation inputs can be directly converted into torque inputs suggesting that systems with soft pneumatic actuators or dielectric elastomers can be modeled with the tools presented. Based on fundamental assumptions in the physics, we show how our model complexity scales linearly with the number of passive shape coordinates. This offers a large reduction on the number of trials needed to identify the system model from experimental data, and may reduce overfitting. The sample efficiency of our method suggests its use in modeling, control, and optimization in robotics, and as a tool for the study of organismal motion in friction dominated regimes.

scholarly journals O Desporto visto por uma Ética de Ausência para o Bem-estar: por uma nova missão

2020 ◽  
Vol 6 (3) ◽  
pp. 59-67
Author(s):  
Rui Pereira
Keyword(s):  
Good Life ◽  
Well Being ◽  
Human Action ◽  
The Body ◽  
Human Soul ◽  
Definition Of ◽  
The Individual ◽  
The Mind ◽  
Good And Evil

There is an ancient view according to which the great meaning of life is to live it in Well-Being, also considered here as an educated life. The task proposed here is to contribute to clarifying the role of sport for this purpose, which is to live a good life. Fundamentally, it seeks to argue that well-being is linked to an ethics that transcends the mere discussion of good and evil and that such is the profound expression of the natural longings of the human soul that in essence is mirrored in the act of love as a disinterested giving. First, there is a parallel between art and sport as large areas of human action that can better reveal such fundamental disinterest, leading us to the friendship associated with the concept of “Fair Play”. From here follows the proposal for a definition of sport that best serves such friendship for well-being. Thus, a vision of well-being is introduced as the absence of seven forms of disorder. Then, as an example of a form of disorder that can easily arise in sport, we analyse the phenomenon of “racism”, here called phenocism after the concept of phenotype. This is carried under the light of an ethics for absence of disorder. Such analysis leads us, finally, to the trilogy freedom-equality-fraternity and there is an insistence on the urgency of sport to fulfil its mission by assuming itself as the massifier of techniques for promoting the performances of the mind, alongside those of the body, for the well-being of the individual. Thus, fulfilling the revolution of the "healthy mind in a healthy body".

scholarly journals Vestibular compensation in lampreys: impairment and recovery of equilibrium control during locomotion

1997 ◽  
Vol 200 (10) ◽  
pp. 1459-1471 ◽  
Author(s):  
T Deliagina
Keyword(s):  
Control System ◽  
Body Shape ◽  
The Body ◽  
Vestibular Compensation ◽  
Motor Deficit ◽  
Loss Of Function ◽  
Roll Control ◽  
Locomotor Pattern ◽  
Equilibrium Control

Removal of a vestibular organ (unilateral labyrinthectomy, UL) in the lamprey (Lampetra fluviatilis) results in a loss of equilibrium, so that the animal rolls (rotates around its longitudinal axis) almost continuously when swimming. This paper describes (i) UL-evoked disturbances of the pattern of locomotory movements responsible for rolling, (ii) recovery of equilibrium control after UL (vestibular compensation), and (iii) the role of vision in the recovery of equilibrium control. It was found that rolling is caused by an asymmetry in the undulatory locomotory movements, with larger deviations of the head towards the side with an intact labyrinth. The rolling appeared to be synchronized with the undulatory locomotory rhythm: during one complete roll turn (360 &deg;), two cycles of locomotion were performed. A characteristic feature of the UL-induced motor deficit in the lamprey is the alternation of episodes of impaired swimming (with a distortion of the body shape and of the locomotor pattern and with a loss of equilibrium) with episodes of normal swimming (without any marked distortion of the locomotor pattern or loss of equilibrium). In the course of recovery after UL, the duration and frequency of the appearance of episodes of normal swimming increased, whereas episodes of impaired swimming became less frequent and shorter. The recovery of equilibrium control and the role of vision in recovery were investigated in lampreys with different combinations of lesions to the vestibular and visual sensory organs. In group 1 (UL only) animals, the time required for 80 % recovery was, on average, 33 days. In group 2 (UL and removal of both eyes) and in group 3 (UL and removal of the contralateral eye) animals, vestibular compensation was considerably retarded, and normal functioning of the roll control system was not regained even 3 months after UL. In contrast, in group 4 (UL and removal of the ipsilateral eye) animals, no impairment of the equilibrium control was observed, and the animals swam without rolling immediately after surgery. These findings indicate (i) that the visual system is important for the process of vestibular compensation, and (ii) that the deficiency in equilibrium control caused by UL can be abolished by means of unilateral (contralateral to UL) visual input. The hypothesis is advanced that the main UL-evoked motor deficit in the lamprey (loss of equilibrium) is primarily caused not by a persistent static distortion of the body shape, but by a loss of function of the roll control system responsible for stabilization of the dorsal-side-up orientation during swimming. A conceptual model of the roll control system of the lamprey, formulated in our previous studies, is used here to present arguments in favour of this hypothesis.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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