scholarly journals Exploiting Spherical Projections To Generate Human-Like Wrist Pointing Movements

2021 ◽  
Author(s):  
Carlo Tiseo ◽  
Sydney Rebecca Charitos ◽  
Michael Mistry
Keyword(s):  
Pointing Movements

Task and effector constraints on the kinematics of pointing movements

2005 ◽  
Author(s):  
Michael Bohan ◽  
Daniel McConnell ◽  
Shelby Thompson ◽  
Alex Chaparro
Keyword(s):  
Pointing Movements

scholarly journals Kinematics of prehension and pointing movements in C6 quadriplegic patients

Spinal Cord ◽  
2000 ◽  
Vol 38 (6) ◽  
pp. 354-362 ◽  
Author(s):  
I Laffont ◽  
E Briand ◽  
O Dizien ◽  
M Combeaud ◽  
B Bussel ◽  
...  
Keyword(s):  
Pointing Movements

“Motor Oblique Effect”: Perceptual Direction Discrimination and Pointing to Memorized Visual Targets Share the Same Preference for Cardinal Orientations

2007 ◽  
Vol 97 (2) ◽  
pp. 1068-1077 ◽  
Author(s):  
Nikolaos Smyrnis ◽  
Asimakis Mantas ◽  
Ioannis Evdokimidis
Keyword(s):  
Visual Target ◽  
Motor Task ◽  
Oblique Effect ◽  
Quadratic Function ◽  
Initial Direction ◽  
Direction Discrimination ◽  
Pointing Movements ◽  
Equivalent Measure ◽  
Visual Targets ◽  
Target Locations

In previous studies we observed a pattern of systematic directional errors when humans pointed to memorized visual target locations in two-dimensional (2-D) space. This directional error was also observed in the initial direction of slow movements toward visual targets or movements to kinesthetically defined targets in 2-D space. In this study we used a perceptual experiment where subjects decide whether an arrow points in the direction of a visual target in 2-D space and observed a systematic distortion in direction discrimination known as the “oblique effect.” More specifically, direction discrimination was better for cardinal directions than for oblique. We then used an equivalent measure of direction discrimination in a task where subjects pointed to memorized visual target locations and showed the presence of a motor oblique effect. We finally modeled the oblique effect in the perceptual and motor task using a quadratic function. The model successfully predicted the observed direction discrimination differences in both tasks and, furthermore, the parameter of the model that was related to the shape of the function was not different between the motor and the perceptual tasks. We conclude that a similarly distorted representation of target direction is present for memorized pointing movements and perceptual direction discrimination.

A Kinematic Evaluation of Linear and Parabolic Pointing in Virtual Reality

2021 ◽  
Vol 65 (1) ◽  
pp. 86-90
Author(s):  
John Sermarini ◽  
Joseph T. Kider ◽  
Joseph J. LaViola ◽  
Daniel S. McConnell
Keyword(s):  
Virtual Reality ◽  
Virtual Environments ◽  
Movement Time ◽  
Interaction Style ◽  
Task Constraint ◽  
Immersive Virtual Environments ◽  
Pointing Task ◽  
Pointing Movements ◽  
Movement Distance ◽  
Kinematic Evaluation

We present the results of a study investigating the influence of task and effector constraints on the kinematics of pointing movements performed in immersive virtual environments. We compared the effect of target width, as a task constraint, to the effect of movement distance, as an effector constraint, in terms of overall effect on movement time in a pointing task. We also compared a linear ray-cast pointing technique to a parabolic pointing technique to understand how interaction style may be understood in the context of task and effector constraints. The effect of target width as an information constraint on pointing performance was amplified in VR. Pointing technique acted as an effector constraint, with linear ray-cast pointing resulting in faster performance than parabolic pointers.

An Unlearned Principle for Controlling Natural Movements

1999 ◽  
Vol 82 (1) ◽  
pp. 255-259 ◽  
Author(s):  
Frank T.J.M. Zaal ◽  
Kristin Daigle ◽  
Gerald L. Gottlieb ◽  
Esther Thelen
Keyword(s):  
Degrees Of Freedom ◽  
Sagittal Plane ◽  
Arm Movement ◽  
First Year ◽  
Strong Constraint ◽  
A Value ◽  
Pointing Movements ◽  
Before And After ◽  
First Year Of Life ◽  
Coordination Patterns

Recently, Gottlieb and colleagues discovered a linear relation between elbow and shoulder dynamic torque in natural pointing movements in the sagittal plane. The present study investigates if the process of learning to reach involves discovering this linearity principle. We inspected torque data from four infants who were learning to reach and grab a toy in front of them. In a longitudinal study, we collected data both in the period before and after they performed their first successful reaches. Torque profiles at the shoulder and elbow were typically multipeaked and became more and more biphasic toward the end of the first year of life. Torques at the shoulder and elbow were correlated tightly for movements in the prereaching period as well as for reaches later in the year. Furthermore, slopes of a regression of shoulder dynamic torque on elbow dynamic torque were remarkably constant at a value ∼2.5–3.0. If linear synergy is used by the nervous system to reduce the controlled degrees of freedom, it will act as a strong constraint on the complex of possible coordination patterns for arm movement early in life. Natural reaching movements can capitalize on this constraint because it simplifies the process of learning to reach.

Sign in / Sign up

Export Citation Format

Share Document