Complex Unconstrained Three-Dimensional Hand Movement and Constant Equi-Affine Speed

2009 ◽  
Vol 101 (2) ◽  
pp. 1002-1015 ◽  
Author(s):  
Uri Maoz ◽  
Alain Berthoz ◽  
Tamar Flash
Keyword(s):  
Power Law ◽  
Hand Movement ◽  
Three Dimensional ◽  
Hand Movements ◽  
Human Hand ◽  
Local Geometry ◽  
Planning And Control ◽  
Human Movements ◽  
And Control ◽  
Geometry And Kinematics

One long-established simplifying principle behind the large repertoire and high versatility of human hand movements is the two-thirds power law—an empirical law stating a relationship between local geometry and kinematics of human hand trajectories during planar curved movements. It was further generalized not only to various types of human movements, but also to motion perception and prediction, although it was unsuccessful in explaining unconstrained three-dimensional (3D) movements. Recently, movement obeying the power law was proved to be equivalent to moving with constant planar equi-affine speed. Generalizing such motion to 3D space—i.e., to movement at constant spatial equi-affine speed—predicts the emergence of a new power law, whose utility for describing spatial scribbling movements we have previously demonstrated. In this empirical investigation of the new power law, subjects repetitively traced six different 3D geometrical shapes with their hand. We show that the 3D power law explains the data consistently better than both the two-thirds power law and an additional power law that was previously suggested for spatial hand movements. We also found small yet systematic modifications of the power-law's exponents across the various shapes, which further scrutiny suggested to be correlated with global geometric factors of the traced shape. Nevertheless, averaging over all subjects and shapes, the power-law exponents are generally in accordance with constant spatial equi-affine speed. Taken together, our findings provide evidence for the potential role of non-Euclidean geometry in motion planning and control. Moreover, these results seem to imply a relationship between geometry and kinematics that is more complex than the simple local one stipulated by the two-thirds power law and similar models.

scholarly journals Reaching to inhibit a prepotent response: A wearable 3-axis accelerometer kinematic analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254514
Author(s):  
Alessia Angeli ◽  
Irene Valori ◽  
Teresa Farroni ◽  
Gustavo Marfia
Keyword(s):  
Low Cost ◽  
Motor Planning ◽  
Cognitive Mechanisms ◽  
Dominant Response ◽  
Planning And Control ◽  
Prepotent Response ◽  
Human Movements ◽  
Kinematic Measures ◽  
And Control ◽  
Selection Of

The present work explores the distinctive contribution of motor planning and control to human reaching movements. In particular, the movements were triggered by the selection of a prepotent response (Dominant) or, instead, by the inhibition of the prepotent response, which required the selection of an alternative one (Non-dominant). To this end, we adapted a Go/No-Go task to investigate both the dominant and non-dominant movements of a cohort of 19 adults, utilizing kinematic measures to discriminate between the planning and control components of the two actions. In this experiment, a low-cost, easy to use, 3-axis wrist-worn accelerometer was put to good use to obtain raw acceleration data and to compute and break down its velocity components. The values obtained with this task indicate that with the inhibition of a prepotent response, the selection and execution of the alternative one yields both a longer reaction time and movement duration. Moreover, the peak velocity occurred later in time in the non-dominant response with respect to the dominant response, revealing that participants tended to indulge more in motor planning than in adjusting their movement along the way. Finally, comparing such results to the findings obtained by other means in the literature, we discuss the feasibility of an accelerometer-based analysis to disentangle distinctive cognitive mechanisms of human movements.

scholarly journals Three-dimensional visualization of mission planning and control for the NPS autonomous underwater vehicle

1990 ◽  
Vol 15 (3) ◽  
pp. 217-221 ◽  
Author(s):  
M.J. Zyda ◽  
R.B. McGhee ◽  
S. Kwak ◽  
D.B. Nordman ◽  
R.C. Rogers ◽  
...  
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Three Dimensional ◽  
Underwater Vehicle ◽  
Mission Planning ◽  
Planning And Control ◽  
And Control

Planning and control of three-dimensional multi-agent formations

2012 ◽  
Vol 30 (2) ◽  
pp. 265-284 ◽  
Author(s):  
G. Wen ◽  
Z. Peng ◽  
Y. Yu ◽  
A. Rahmani
Keyword(s):  
Three Dimensional ◽  
Planning And Control ◽  
Multi Agent ◽  
And Control

Analysis and Systematic Classification of Human Hand Movement for Robot Hand Design

2008 ◽  
Vol 20 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Takeshi Ninomiya ◽  
◽  
Takashi Maeno ◽  
Keyword(s):  
Hand Movement ◽  
Hand Movements ◽  
Human Hand ◽  
Robot Hand ◽  
Systematic Classification ◽  
Robot Hands ◽  
Human Muscles ◽  
Set Up ◽  
Human Hands

The systematic classification of hand movements, which indicates the minimum mechanism of robot hands, is suggested. The performance of existent robot hands is not as high as that of human hands because the performance of existent actuators does not come up to that of human muscles in the same volume. It is important for robot hands to accomplish targeted tasks with a minimum mechanism. Human hand movements are analyzed quantitatively considering robot hands such as associated movement of DIP and PIP joints. Based on the results of analysis, we obtain three items, i.e., fingers, joints that must be set up actuators and basic movements we define. We systematically classify human hand movement for the robot hand based on three items.

Eye Movements When Observing Predictable and Unpredictable Actions

2006 ◽  
Vol 96 (3) ◽  
pp. 1358-1369 ◽  
Author(s):  
Gerben Rotman ◽  
Nikolaus F. Troje ◽  
Roland S. Johansson ◽  
J. Randall Flanagan
Keyword(s):  
Eye Movements ◽  
Hand Movement ◽  
Landing Site ◽  
Movement Planning ◽  
Gaze Behavior ◽  
Direct Gaze ◽  
Planning And Control ◽  
Landing Sites ◽  
Target Block ◽  
And Control

We previously showed that, when observers watch an actor performing a predictable block-stacking task, the coordination between the observer's gaze and the actor's hand is similar to the coordination between the actor's gaze and hand. Both the observer and the actor direct gaze to forthcoming grasp and block landing sites and shift their gaze to the next grasp or landing site at around the time the hand contacts the block or the block contacts the landing site. Here we compare observers' gaze behavior in a block manipulation task when the observers did and when they did not know, in advance, which of two blocks the actor would pick up first. In both cases, observers managed to fixate the target ahead of the actor's hand and showed proactive gaze behavior. However, these target fixations occurred later, relative to the actor's movement, when observers did not know the target block in advance. In perceptual tests, in which observers watched animations of the actor reaching partway to the target and had to guess which block was the target, we found that the time at which observers were able to correctly do so was very similar to the time at which they would make saccades to the target block. Overall, our results indicate that observers use gaze in a fashion that is appropriate for hand movement planning and control. This in turn suggests that they implement representations of the manual actions required in the task and representations that direct task-specific eye movements.

scholarly journals A customizable tablet app for hand movement research outside the lab

2019 ◽  
Author(s):  
Adam Matic ◽  
Alex Gomez-Marin
Keyword(s):  
Open Source ◽  
Power Law ◽  
Hand Movement ◽  
Human Hand ◽  
List Type ◽  
Study Behavior ◽  
Movement Trajectories ◽  
Behavioral Studies ◽  
Art Research ◽  
High Throughput Experiments

ABSTRACTBackgroundPrecise behavioral measurements allow the discovery of movement constraints that provide insights into sensory-motor processes and their underlying neural mechanisms. For instance, when humans draw an ellipse on a piece of paper, the instantaneous speed of the pen co-varies tightly with the local curvature of the path. Known as the speed-curvature power law, this phenomenon relates to fundamental questions of motor control.New MethodWe have developed a software app for displaying static curves or dynamic targets while recording finger or stylus movements on Android touch-screen tablets. Designed for human hand movement research, the app is free, ready-to-use, open-source and customizable.ResultsWe provide a template experimental protocol, and detailed explanations to use it and flexibly modify the code for different kinds of tasks. Our validation of the app demonstrates laboratory-quality results outside the laboratory. We also provide raw data and analysis scripts.Comparison with Existing MethodsCommonly used laboratory devices for recording hand movement trajectories are large, heavy and expensive. In turn, software apps are often not published, nor customizable. Our app running on tablets becomes an affordable, flexible, and portable tool suited for quantitative and robust behavioral studies with large number of participants and outside the laboratory (e.g. in a classroom, a hospital, or at home).ConclusionsThe affordability, flexibility, and resolution of our tablet app provide an effective tool to study behavior quantitatively in the real world.HighlightsA free, ready-to-use, open source, and customizable app for Android tablets.High-resolution measuring of finger movement during tracing, tracking & scribbling.Fast and easy data collection and experimental design with affordable hardware.Allowing for high-throughput experiments outside the lab (classroom, hospital, home).Validated for state-of-the-art research (speed-curvature power law, drawing accuracy).

scholarly journals A Method for Measuring the Height of Hand Movements Based on a Planar Array of Electrostatic Induction Electrodes

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2943
Author(s):  
Linyi Zhang ◽  
Xi Chen ◽  
Pengfei Li ◽  
Chuang Wang ◽  
Mengxuan Li
Keyword(s):  
Human Body ◽  
Hand Movement ◽  
Electrode Array ◽  
Hand Movements ◽  
Human Hand ◽  
Human Computer Interactions ◽  
Sensing System ◽  
Electrostatic Induction ◽  
Planar Array ◽  
Measurement Algorithm

This paper proposes a method based on a planar array of electrostatic induction electrodes, which uses human body electrostatics to measure the height of hand movements. The human body is electrostatically charged for a variety of reasons. In the process of a hand movement, the change of a human body’s electric field is captured through the electrostatic sensors connected to the electrode array. A measurement algorithm for the height of hand movements is used to measure the height of hand movements after the direction of it has been obtained. Compared with the tridimensional array, the planar array has the advantages of less space and easy deployment; therefore, it is more widely used. In this paper, a human hand movement sensing system based on human body electrostatics was established to perform verification experiments. The results show that this method can measure the height of hand movements with good accuracy to meet the requirements of non-contact human-computer interactions.

Spatial constant equi-affine speed and motion perception

2014 ◽  
Vol 111 (2) ◽  
pp. 336-349 ◽  
Author(s):  
Uri Maoz ◽  
Tamar Flash
Keyword(s):  
Motion Perception ◽  
Power Law ◽  
Critical Role ◽  
Three Dimensional ◽  
Affine Geometry ◽  
Human Hand ◽  
Viewing Distance ◽  
Spatial Motion ◽  
Elliptical Motion

The two-thirds power law, postulating an inverse local relation between the velocity and cubed root of curvature of planar trajectories, is a long-established simplifying principle of human hand movements. In perception, the motion of a dot along a planar elliptical path appears most uniform for speed profiles closer to those predicted by the power law than to constant Euclidean speed, a kinetic-visual illusion. Mathematically, complying with this law is equivalent to moving at constant planar equi-affine speed, while unconstrained three-dimensional drawing movements generally follow constant spatial equi-affine speed. Here we test the generalization of this illusion to visual perception of spatial motion for a dot moving along five differently shaped paths, using stereoscopic projection. The movements appeared most uniform for speed profiles closer to constant spatial equi-affine speed than to constant Euclidean speed, with path torsion (i.e., local deviation from planarity) directly affecting the speed profiles perceived as most uniform, as predicted for constant spatial equi-affine speed. This demonstrates the dominance of equi-affine geometry in spatial motion perception. However, constant equi-affine speed did not fully account for the variability among the speed profiles selected as most uniform for different shapes. Moreover, in a followup experiment, we found that viewing distance affected the speed profile reported as most uniform for the extensively studied planar elliptical motion paths. These findings provide evidence for the critical role of equi-affine geometry in spatial motion perception and contribute to the mounting evidence for the role of non-Euclidean geometries in motion perception and production.

scholarly journals Reaching to inhibit a prepotent response: a wearable 3-axis accelerometer kinematic analysis

2021 ◽  
Author(s):  
Alessia Angeli ◽  
Irene Valori ◽  
Teresa Farroni ◽  
Gustavo Marfia
Keyword(s):  
Low Cost ◽  
Motor Planning ◽  
Cognitive Mechanisms ◽  
Planning And Control ◽  
Prepotent Response ◽  
Human Movements ◽  
Acceleration Data ◽  
Kinematic Measures ◽  
And Control ◽  
Selection Of

AbstractThe present work explores the distinctive contribution of motor planning and control to human reaching movements. In particular, the movements were triggered by the selection of a prepotent response (Dominant) or, instead, by the inhibition of the prepotent response, that required the selection of an alternative one (Non-dominant). To this aim, we adapted a Go/No-Go task to investigate both the dominant and non-dominant movements of a cohort of 19 adults, utilizing kinematic measures to discriminate between the planning and control components of the two actions. To sample such measures, a low-cost, easy to use, 3-axis wrist worn accelerometer was put to good use to obtain raw acceleration data and to compute and break down its velocity components. The values obtained with such task indicate that with the inhibition of a prepotent response, the selection and execution of the alternative one yields both a longer reaction time and movement duration. Moreover, the peak velocity occurred later in time with respect to the dominant response, revealing that participants tended to indulge more in motor planning rather than in adjusting their movement along the way. Finally, comparing such results to the findings obtained by other means in literature, we discuss the feasibility of an accelerometer-based analysis to disentangle distinctive cognitive mechanisms of human movements.

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