The origin and use of positional frames of reference in motor control

1995 ◽  
Vol 18 (4) ◽  
pp. 723-744 ◽  
Author(s):  
Anatol G. Feldman ◽  
Mindy F. Levin
Keyword(s):  
Nervous System ◽  
Degrees Of Freedom ◽  
Motor Behavior ◽  
Physiological Mechanism ◽  
Empirical Support ◽  
Movement Control ◽  
Frame Of Reference ◽  
Frames Of Reference ◽  
Movement Trajectory ◽  
Control Variables

AbstractA hypothesis about sensorimotor integration (the λ model) is described and applied to movement control and kinesthesia. The central idea is that the nervous system organizes positional frames of reference for the sensorimotor apparatus and produces active movements by shifting the frames in terms of spatial coordinates. Kinematic and electromyographic patterns are not programmed, but emerge from the dynamic interaction among the system s components, including external forces within the designated frame of reference. Motoneuronal threshold properties and proprioceptive inputs to motoneurons may be cardinal components of the physiological mechanism that produces positional frames of reference. The hypothesis that intentional movements are produced by shifting the frame of reference is extended to multi-muscle and multi-degrees-of-freedom systems with a solution of the redundancy problem that allows the control of a joint alone or in combination with other joints to produce any desired limb configuration and movement trajectory. The model also implies that for each motor behavior, the nervous system uses a strategy that minimizes the number of changeable control variables and keeps the parameters of these changes invariant. Examples are provided of simulated kinematic and electromyographic signals from single- and multi-joint arm movements produced by suggested patterns of control variables. Empirical support is provided and additional tests of the model are suggested. The model is contrasted with others based on the ideas of programming of motoneuronal activity, muscle forces, stiffness, or movement kinematics.

Adaptability of innate motor patterns and motor control mechanisms

1986 ◽  
Vol 9 (4) ◽  
pp. 585-599 ◽  
Author(s):  
M. B. Berkinblit ◽  
A. G. Feldman ◽  
O. I. Fukson
Keyword(s):  
Nervous System ◽  
Motor Control ◽  
Degrees Of Freedom ◽  
Behavioral Plasticity ◽  
Motor Behavior ◽  
Voluntary Control ◽  
Control Mechanisms ◽  
Motor Equivalence ◽  
Motor Patterns ◽  
Dynamic Components

AbstractThe following factors underlying behavioral plasticity are discussed: (1) reflex adaptability and its role in the voluntary control of movement, (2) degrees of freedom and motor equivalence, and (3) the problem of the discrete organization of motor behavior. Our discussion concerns a variety of innate motor patterns, with emphasis on the wiping reflex in the frog.It is proposed that central regulation of stretch reflex thresholds governs voluntary control over muscle force and length. This suggestion is an integral part of the equilibrium-point hypothesis, two versions of which are compared.Kinematic analysis of the wiping reflex in the spinal frog has shown that each stimulated skin site is associated with a group of different but equally effective trajectories directed to the target site. Such phenomena reflect the principle of motor equivalence -the capacity of the neuronal structures responsible for movement to select one or another of a set of possible trajectories leading to the goal. Redundancy of degrees of freedom at the neuronal level as well as at the mechanical level of the body's joints makes motor equivalence possible. This sort of equivalence accommodates the overall flexibility of motor behavior.An integrated behavioral act or a single movement consists of dynamic components. We distinguish six components for the wiping reflex, each associated with a certain functional goal, specific body positions, and motor-equivalent movement patterns. The nervous system can combine the available components in various ways in forming integrated behavioral sequences. The significance of command neuronal organization is discussed with respect to (1) the combinatory strategy of the nervous system and (2) the relation between continuous and discrete forms of motor control. We conclude that voluntary movements are effected by the central nervous system with the help of the mechanisms that underlie the variability and modifiability of innate motor patterns.

scholarly journals A test of spatial temporal decoding mechanisms in the superior colliculus

2012 ◽  
Vol 107 (9) ◽  
pp. 2442-2452 ◽  
Author(s):  
Husam A. Katnani ◽  
A. J. Van Opstal ◽  
Neeraj J. Gandhi
Keyword(s):  
Nervous System ◽  
Motor Control ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Motor Behavior ◽  
Saccadic Eye Movements ◽  
Population Coding ◽  
Population Activity ◽  
Low Levels

Population coding is a ubiquitous principle in the nervous system for the proper control of motor behavior. A significant amount of research is dedicated to studying population activity in the superior colliculus (SC) to investigate the motor control of saccadic eye movements. Vector summation with saturation (VSS) has been proposed as a mechanism for how population activity in the SC can be decoded to generate saccades. Interestingly, the model produces different predictions when decoding two simultaneous populations at high vs. low levels of activity. We tested these predictions by generating two simultaneous populations in the SC with high or low levels of dual microstimulation. We also combined varying levels of stimulation with visually induced activity. We found that our results did not perfectly conform to the predictions of the VSS scheme and conclude that the simplest implementation of the model is incomplete. We propose that additional parameters to the model might account for the results of this investigation.

scholarly journals Perspective construal techniques in indirect non-referential naming

2020 ◽  
pp. 188-204
Author(s):  
M. I. Kiose ◽  
Keyword(s):  
Correlation Analysis ◽  
Frame Of Reference ◽  
Frames Of Reference ◽  
Final Position ◽  
Reference Coordinate System ◽  
Complex Procedure ◽  
Focus Type ◽  
Comparative Constructions ◽  
Reference Distance ◽  
Fictive Motion

The research explores the perspective construal techniques applied in predicate indirect noun groups in Russian. In this case, the discourse perspective is construed with a highly salient ob-ject of perspective in the construed frame of reference. To achieve this effect, the speaker / narrator chooses a particular type of predicate indirect noun groups, such as predicate con-structions with the verbs of fictive motion, appearance, and being (existence) or comparative constructions. Each of these construction types demonstrates its own linguistic and cognitive features, which are used to apply various perspectivization techniques to ensure that its inter-pretation will proceed successfully. To detect these techniques, a complex procedure is applied. Hand-selected fragments analysis followed by corpus statistic and correlation analysis help define the parameters and values in predicate indirect noun group constructions. These parameters are referential (bodily modus type, referent type, referent focus type), lexical (first / repeated lexeme use, type of attribute in pre-position, intensifier type in pre-position), syntactic (sentence initial / final position, position before a clause, co-reference distance in words and propositions) and textual ones (textual role, new microevent introduction). Vari-ance analysis has revealed a group of parameters typical for the studied construction types of predicate indirect noun groups. Parametric results allow describe the typical techniques of object mental scanning, object construal, frames of reference (coordinate system) construal. These include the techniques of mental path shortening / prolongation, embodiment con- strual alleviation / constraining, animated / non-animated object construal, stability / instabil-ity of frames of reference, etc.

scholarly journals Torsion or not torsion, that is the question

2016 ◽  
Vol 25 (12) ◽  
pp. 1644013 ◽  
Author(s):  
Yuri Bonder
Keyword(s):  
General Relativity ◽  
Degrees Of Freedom ◽  
Empirical Support ◽  
Experimental Tests ◽  
Spin Polarized ◽  
Empirical Tests ◽  
New Interactions

A hypothesis of general relativity (GR) is that spacetime torsion vanishes identically. This assumption has no empirical support; in fact, a nonvanishing torsion is compatible with all the experimental tests of GR. The first part of this essay specifies the framework that is suitable to test the vanishing-torsion hypothesis, and an interesting relation with the gravitational degrees of freedom is suggested. In the second part, some original empirical tests are proposed based on the observation that torsion induces new interactions between different spin-polarized particles.

Verbal and Math Self-Concepts: An Internal/External Frame of Reference Model

1986 ◽  
Vol 23 (1) ◽  
pp. 129-149 ◽  
Author(s):  
Herbert W. Marsh
Keyword(s):  
Math Achievement ◽  
Reference Model ◽  
Empirical Support ◽  
Frame Of Reference ◽  
Self Concept ◽  
Math Skills ◽  
Verbal Skills ◽  
External Process ◽  
External Frame ◽  
Verbal Achievement

The purpose of this investigation is to examine empirical support for the internal/external (I/E) frame of reference model that describes the relation between Verbal and Math self-concepts, and between these academic self-concepts and verbal and math achievement. The empirical tests are based on all studies (n = 6,010; age range = 7–35+ years) that have employed the Self Description Questionnaire (SDQ), SDQII, or SDQ III self-concept instruments. The I/E model posits, for example, that a high Math self-concept is more likely when math skills are good relative to those of peers (an external comparison) and when math skills are better than verbal skills (an internal comparison). Consistent with the model and empirical findings, (a) Verbal and Math self-concepts are nearly uncorrelated with each other even though verbal and math achievement indicators are substantially correlated with each other and with the matching areas of self-concept; (b) the direct effects of math achievement on Verbal self-concept, and of verbal achievement on Math self-concept, are both negative. For inferred self-concepts based on the ratings of external observers, the external process seems to operate, but not the internal process. The findings demonstrate that academic self-concepts are affected by different processes than are the academic achievement areas they reflect and the inferred self-concepts offered by external observers.

Action, Movement, and Culture: Does Culture Shape Movement?

2018 ◽  
Vol 7 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Blandine Bril
Keyword(s):  
Cultural Diversity ◽  
Motor Skills ◽  
Degrees Of Freedom ◽  
Motor Behavior ◽  
Raw Materials ◽  
Critical Dimension ◽  
Metabolic Processes ◽  
Cultural Variations ◽  
Functional Perspective ◽  
Physical Environments

What any traveler can definitely notice is the incredible diversity of everyday skills due to the cultural diversity of tools, raw materials, physical environments, or local postural habits that set up the conditions for performing tasks. Do cultural environments influence motor skills? Are there “motor styles” common to members of a given cultural group? Focusing on instrumental everyday actions from a functional perspective, we propose four cases to illustrate in detail cultural variations in motor behavior. The first example explores the movement repertoire of expert potters from two cultural backgrounds when asked to produce pots of the same shape. A second example analyzes how a dance figure based on the same mechanical principles gives rise to different cultural aesthetics. The third example questions the adaptation of metabolic processes while performing the same load-carrying task in various physical environments. The last example brings up the issue of cultural choices of working and resting postures. Each case refers to a critical dimension of what generates the cultural diversity of motor skills: operational equivalence of movements, variation in the “weighing” of the parameters of the action, adaptation of metabolic processes, and adaptive benefit of specific posture. We conclude that if the countless diversity of cultural contexts and tasks give rise to an enormous diversity of movements and postures, this diversity is anchored in the many degrees of freedom of the organism. It is this profusion of degrees of freedom that sustains the endless variations of cultural motor skills giving ways to infinite manners of using one’s own body.

An Energy Frame of Reference to Assess Vehicle’s Physical Externalities

2020 ◽  
Author(s):  
Frank Otremba ◽  
José A. Romero Navarrete ◽  
Alejandro A. Lozano Guzmán
Keyword(s):  
Environmental Conditions ◽  
Statistical Models ◽  
Degrees Of Freedom ◽  
Asphalt Pavement ◽  
Frame Of Reference ◽  
Deterministic Approach ◽  
Road Transportation ◽  
The Road ◽  
Pavement Damage ◽  
Simulation Scheme

Abstract Externalities of the road transportation are multidimensional in nature and involve the road-vehicle interaction under different environmental conditions. Estimating the pavement and vehicle damage potentials as a function of the conditions under which such interaction takes place, is important to avoid accelerated or catastrophic damages in these systems. Such an assessing is crucial from the perspective of pricing the effects of the vehicle on the infrastructure and vice versa. The existing models for pricing such interaction, critically depends on gross average statistical models. In this paper, it is proposed a deterministic approach to realize such an assessment, based upon validated approaches for the pavement damage. The simulation scheme considers different degrees-of-freedom vehicle models, and a discrete asphalt pavement, that make possible the simulation of massive traffic situations on realistic road lengths.

Frames of Reference for Hand Orientation

1995 ◽  
Vol 7 (2) ◽  
pp. 182-195 ◽  
Author(s):  
Martha Flanders ◽  
John F. Soechting
Keyword(s):  
Reference Frame ◽  
Neural Control ◽  
Human Subjects ◽  
Object Orientation ◽  
Frame Of Reference ◽  
Object Location ◽  
Frames Of Reference ◽  
Spatial Reference ◽  
Hand Orientation ◽  
Spatial Reference Frame

In reaching and grasping movements, information about object location and object orientation is used to specify the appropriate proximal arm posture and the appropriate positions for the wrist and fingers. Since object orientation is ideally defined in a frame of reference fixed in space, this study tested whether the neural control of hand orientation is also best described as being in this spatial reference frame. With the proximal arm in various postures, human subjects used a handheld rod to approximate verbally defined spatial orientations. Subjects did quite well at indicating spatial vertical and spatial horizontal but made consistent errors in estimating 45° spatial slants. The errors were related to the proximal arm posture in a way that indicated that oblique hand orientations may be specified as a compromise between a reference frame fixed in space and a reference frame fixed to the arm. In another experiment, where subjects were explicitly requested to use a reference frame fixed to the arm, the performance was consistently biased toward a spatial reference frame. The results suggest that reaching and grasping movements may be implemented as an amalgam of two frames of reference, both neurally and behaviorally.

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