Attention and Performance Xiii

Motor Representation and Control

Marc Jeannerod

• Publisher: Psychology Press
• Year: 2018
• ISBN:
  9781134753697
• Edition: 1
• Topic: Psicología
• Subtopic: Historia y teoría en psicología

Compiled as a result of the Thirteenth Symposium of the Association for Attention and Performance, this collection focuses on the Symposium's theme: Organization of Action. The book is arranged in sections which provide a comprehensive view of the main issues raised during the meeting. Several aspects of the theme were considered, including: the anatomical and physiological constraints on motor preparation and execution. the influence of control (proprioceptive, cutaneous, visual, oculomotor) signals the contribution of kinematics to the understanding of the underlying mechanisms and the role of cognitive constraints such as attention or learning in goal selection This new volume is of particular interest to professionals and researchers in cognitive psychology, physiology, and neuropsychology as well as those studying motor skills.

1 Hierarchical Control in the Execution of Action Sequences: Tests of Two Invariance Properties

Saul Sternberg
University of Pennsylvania
Ronald L, Knoll
AT&T Bell Laboratories
David L. Turock
Bell Communications Research

Abstract

What might it mean for execution of an action sequence to be controlled hierarchically? We argue that if production of a sequence consists of the execution of nested constituent subsequences, then it should be characterized by two invariance properties—properties that limit the effects of one part of the sequence on another. Because one such constituent structure merely partitions the stream of action into action units, these properties have wide applicability. According to low-level invariance, the process that executes a constituent should not be influenced by changes in any higher level constituent. According to high-level invariance, changes in a constituent should have at most limited and local effects on higher level constituents. We report on tests of these two properties in the rapid production of brief utterances and short strings of keystrokes, in which we examine the effects of sequence length, serial position, and unit size on measures of timing. The tests support the existence of hierarchical constituents at the level of the stroke in typing and the stress group in speech, but provide only limited evidence for deeper hierarchical structure.

Introduction

In this chapter we investigate one sense in which execution of action sequences might be hierarchical, by virtue of their being composed of separately controlled constituent subsequences. We argue that to claim merely that a continuous stream of action can be decomposed into a string of concatenated units is to assert a simple form of such hierarchical structure; properties that distinguish the constituents in such a structure should thus characterize purported action units. We focus on two invariance properties that flow from this sense of hierarchical control—properties that reflect the idea that different control levels function autonomously and thus impose limits on the effects of sequential context—and report attempts to determine the extent to which these properties characterize timing in the rapid production of speech and keystroke sequences. The spirit of our inquiry is to minimize the number of ancillary assumptions and thus avoid strong models. Our aim is to illustrate some alternative approaches to testing for hierarchical structure, applying them in most cases to data collected for other purposes.

In our examination of evidence we consider instances where short action sequences prescribed well in advance are correctly produced under time pressure, and where time measurements thus indicate performance constraints. We justify this choice of procedure by our desire to separate the execution of planned sequences from the process by which they are planned. Performance measurements indicate that under these conditions a plan or "program" for the entire sequence exists before it is initiated (Rosenbaum, Kenny, & Derr, 1983; Sternberg, Monsell, Knoll, & Wright, 1978). We deliberately do not investigate cases where choice of sequence is free rather than prescribed (e.g., Fentress, 1983), or where errors are of central interest (e.g., Shattuck-Hufnagel, 1983): The choice of action element (when choice is free) or errors in such choice (when the sequence is prescribed) could occur during the planning process as well as the execution process, whereas temporal effects in the execution of prescribed sequences seem more likely to be associated with the latter. Because our concern is with how the control mechanism selects successive actions, we consider primarily sequences whose successive actions are distinct rather than repeating.

Properties of Sequences Under Hierarchical Control

Concepts of Hierarchy

One example of the numerous ways¹ in which the term hierarchy has been used is to denote a simple ordering on some dimension, often described as a set of levels. More interesting are tree-like branching structures, consisting of a set of elements (nodes) at different levels, partially ordered by a relation (branches), usually antisymmetric and transitive (Wall, 1972). Examples of relations are inclusion and control. If the relation is inclusion, we have a classification hierarchy in which each class (at one level) consists of a set of subclasses (at the next), and a subclass can belong to only one class. If the relation is control, each element (at one level) controls a set of elements (at the next), and an element can be controlled by at most one higher level element.

In applying this idea to action sequences we are interested in strings of rapid actions that can be said to contain one or more separately controlled substring constituents (or units), larger than a "single" action (that is, susceptible to further analysis), but smaller than the whole string (Gallistel, 1980, pp. 288-290). The validity of such an assertion hinges theoretically on the specification of criteria that define a substring as a constituent, and empirically on the demonstration that such criteria are satisfied. This sense of hierarchy should be distinguished from the idea of different levels of specificity, such that more detailed aspects of the same action are controlled autonomously at lower levels, closer to its execution (Szentagothai & Arbib, 1975), and where control branches can converge and cross (Gallistel, 1980).

Perhaps the most familiar domain where hierarchically organized sequences have been used to characterize human behavior is language. The constituent structure of sentences is represented in linguistics by the recursively branching phrase marker (Wall, 1972), which we introduce to add precision to the idea of hierarchical structure. The phrase marker can be expressed as either an ordered tree, (Fig. 1.1A), or a labeled-bracket structure (Fig. 1.1B). An ordered tree consists of a set of nodes (from a root at the highest level to leaves at the lowest, or first) connected by diverging and non-crossing branches. Any pair of nodes is related either by dominance (for instance, in Fig. 1.1 VP dominates the right-hand N, and is thus at a higher "level") or by precedence (for instance, the upper NP precedes V) but not by both. Each node corresponds to a substring constituent of the sentence. The nesting of constituents is more evident in the labeled-bracket structure, in which dominance becomes inclusion.

A hierarchically organized string may thus be defined as a set of constituent (sub)strings, partially ordered by inclusion, such that any string either fully contains, or is fully contained in, or is disjoint from any other string, and such that disjoint constituents are temporally ordered. A string of "action unit" substrings defines the most shallow structure that can be described as hierarchical; in a deeper hierarchy the substrings would be further partitioned into smaller disjoint substrings.

FIG. 1.1. Two forms of the phrase marker representation of a sentence. A: An ordered tree composed of nodes and branches. B: A partially equivalent structure of nested labeled brackets.

Two Invariance Properties of Hierarchically Controlled Sequences

Augmenting of hierarchical structure with hierarchical control. The phrase marker is a hierarchical structure with no commitment to any particular embodiment in real time or to any specification of the flow of c...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Preface
• List of Contributors and Participants
• Group Photo
• 1. Hierarchical Control in the Execution of Action Sequences: Tests of Two Invariance Properties
• Abstract
• Introduction
• Properties of Sequences Under Hierarchical Control
• Tests of Low-Level Invariance
• Tests of High-Level Invariance
• Joint Tests of High-Level and Low-Level Invariance
• Conclusions
• Acknowledgments
• References
• PART II: TUTORIALS ON THE BASIC ORGANIZATION PRINCIPLES OF MOTOR REPRESENTATIONS
• Abstract
• The Development of Ideas on Neuronal Hierarchies
• Hierarchic Levels of Cortical Areas
• Concluding Remarks
• Acknowledgments
• References
• 3. Motor Programs: Concepts and Issues
• Abstract
• Hierarchical Conceptions of Programs
• Modularity
• Issues for a Computational Theory of Sequencing
• Summary and Conclusions
• Acknowledgment
• References
• 4. Programs, Schemas, and Neural Networks for Control of Hand Movements: Beyond the RS Framework
• Abstract
• Introduction
• Schema Assemblages
• Motor Set and the Neuralization of Schema Assemblages
• Artificial Neural Networks for Motor Control
• Acknowledgments
• References
• 5. Action-Perception as a Pattern Formation Process
• Abstract
• Introduction
• Methods
• Results and Discussion
• A Theoretical Model
• General Discussion and Summary
• Acknowledgments
• References
• PART III: MOVEMENT INITIATION AND MOTOR OUTPUT SPECIFICATION IN VOLUNTARY ACTION
• 6. Speed-Accuracy Tradeoffs in Aimed Movements: Toward a Theory of Rapid Voluntary Action
• Abstract
• Introduction
• Methodological Framework
• Historical Survey
• Summary
• Stochastic Optimized-submovement Models
• Conclusion
• Acknowledgments
• References
• 7. Neurophysiology of Reaching
• Abstract
• The Combined Behavioral-Neurophysiological Experiment
• Reaching Neurons in Posterior Parietal Cortex (Areas 5 and 7)
• Studies of Reaching in Premotor Cortex
• Studies of Reaching in the Motor Cortex
• Parametric Studies of Reaching in Motor Cortex and Area 5
• Role of Motor Cortex in Reaching
• Motor Cortical Projections to Spinal Cord
• Reaching Circuits in the Spinal Cord
• Acknowledgments
• References
• 8. Parallel Interacting Channels in the Initiation and Specification of Motor Response Features
• Abstract
• Introduction
• Methods
• Results
• Discussion
• Acknowledgments
• References
• 9. Generalized Motor Programs: Reexamining Claims of Effector Independence in Writing
• Abstract
• Introduction
• Method
• Results
• Discussion
• Conclusions
• Acknowledgments
• References
• 10. Constraints for Action Selection: Overhand Versus Underhand Grips
• Abstract
• Introduction
• Experiment 1
• Experiment 2
• Experiment 3
• Hypotheses
• Conclusions
• Acknowledgments
• References
• PART IV. THE STRUCTURE OF MOTOR PATTERNS IN LEARNED MOVEMENTS AND SPEECH
• 11. Common Factors in the Control of Free and Constrained Movements
• Abstract
• The System Analysis Approach to the Study of Tracking
• The Role of Cognitive Factors
• Factors Related to the Implementation of the Response
• Summary and Conclusions
• Acknowledgments
• References
• 12. Rhythmic Precision in the Performance of Piano Scales: Motor Psychophysics and Motor Programming
• Abstract
• Motor Psychophysics and Motor Programming
• Method
• Results
• Discussion
• Acknowledgments
• References
• 13. Rapid Serial Movements: Relation Between the Planning of Sequential Structure and Effector Selection
• Abstract
• Experiment 1
• Experiment 2
• Experiment 3
• General Discussion
• Acknowledgments
• References
• 14. Phase Transitions in Speech Production and Their Perceptual Consequences
• Abstract
• Experiment 1
• Experiment 2
• General Discussion
• Acknowledgments
• References
• 15. Acquisition of Speech Production: Frames, Then Content
• Abstract
• Introduction
• Adult Speech: The Frame/Content Hypothesis
• Early Vocal Communication
• Canonical Babbling
• Canonical Babbling as Pure Frames
• The First Words
• Beyond the First Fifty Words
• Acquisition of Correct Vowel Production: A Case Study
• Processes of Local Modification
• Summary and Implications
• Acknowledgments
• References
• PART V. SENSORIMOTOR TRANSFORMATION AND THE REPRESENTATION OF ACTION COORDINATES
• 16. Sensorimotor Transformations and the Kinematics of Arm Movements in Three-dimensional Space
• Abstract
• Introduction
• Identification of Preferred Coordinate Systems
• Sensorimotor Transformations Between Points in Extrinsic and Intrinsic Frames of Reference
• Wrist Motions in Different Planes in Space
• Conclusion
• Acknowledgment
• References
• 17. The Geometric and Dynamic Implications of the Coherence Constraints in Three-dimensional Sensorimotor Interactions
• Abstract
• Introduction
• The Conceptual Framework
• Quantitative Simulations
• Discussion
• References
• 18. Sensory-Motor Adaptation to High Force Levels in Parabolic Flight Maneuvers
• Abstracts
• Introduction
• Methods
• Results
• Discussion
• Acknowledgments
• References
• 19. Contribution of Skeletal and Extraocular Proprioception to Kinaesthetic Representation
• Abstract
• Introduction
• Results
• Conclusion
• Acknowledgments
• References
• 20. Eye Movements to a Visual Stimulus Flashed Before, During, or After a Saccade
• Abstract
• Introduction
• Method
• Results and Discussion
• Conclusion
• Acknowledgment
• References
• 21. Basic Perceptuo-motor Dysfunctions in Cerebral Palsy
• Abstract
• Introduction
• Two Basic Functions in Perceptuo-motor Development
• Gearing Vision to the Environment
• Linking Propriospecific Information
• Summary and Conclusions
• Acknowledgments
• References
• 22. Joint Visual Attention, Manual Pointing, and Preverbal Communication in Human Infancy
• Abstract
• introduction
• Comprehension of Gaze Direction
• General Methodology of the Studies
• Relation Between Comprehension of Gaze and Comprehension of Pointing
• Joint Visual Attention and Production of Pointing
• Conclusion
• References
• PART VI. THE ROLE OF SENSORY-BASED ADJUSTMENTS IN THE ACHIEVEMENT OF THE GOAL
• 23. Functional Contributions of Rapid and Automatic Sensory-based Adjustments to Motor Output
• Abstract
• Introduction
• Is the Common Ground Common?
• Some Functional and Ecological Perspectives
• A Celebration of Differences
• Acknowledgments
• References
• 24. Gaze Saccade Orienting and Hand Pointing Are Locked to Their Goal by Quick Internal Loops
• Abstract
• Eye-Head Orientation
• Apparatus and Methods
• Results
• Discussion
• General Conclusion
• References
• 25. Tactile Afferent Signals in the Control of Precision Grip
• Abstract
• Introduction
• Methodological Considerations
• Behavioral Observations
• Tactile Afferent Signals and Their Functional Relevance
• General Discussion and Concluding Remarks
• Acknowledgments
• References
• 26. Motor Representations in Deafferented Humans: A Mechanism for Disordered Movement Performance
• Abstract
• Introduction
• Disorders of Voluntary Movements in Deafferented Humans
• Sense of Muscular Effort and Large-Fiber Sensory Neuropathy
• Methods
• Results
• Discussion
• References
• PART VII. CONSTRAINTS ON MOTOR LEARNING AND DEVELOPMENT
• 27. A Perception-Action Perspective on the Development of Manual Movements
• Abstract
• The Sensory Basis of Manual Behavior
• Newborn Reaching
• Reaching and Grasping
• Early Development of Reaching and Grasping
• The Refinement of the Approach
• The Grasping Act
• Catching
• Fine Manual Skills
• Discussion
• Acknowledgments
• References
• 28. Units of Motor Behavior: Modifications with Practice and Feedback
• Abstract
• Paradigm Development
• Discovering of Units of Action in Coincident Timing
• Discussion
• Acknowledgments
• References
• 29. Motor Learning and the Degrees of Freedom Problem
• Abstract
• Terminology
• Motor Learning as Constrained Optimization
• Task Constraints
• Intrinsic Constraints on Motor Learning
• Composite Cost Functionals
• Connectionist Algorithms
• The Network Architecture
• Learning the Forward Model
• Learning Motor Programs
• An Example
• Task Constraints
• Intrinsic Constraints
• Discussion
• Simulations
• Smoothness in a Multi-effector System
• Smoothness in the Endpoint Space of a Multi-effector System
• Distinctiveness in Task Space: Smoothness in Articulatory Space
• Feedback and Feedforward
• Trajectory Formation for a Dynamical Arm
• Learning Parameterized Plans
• Conclusions
• References
• 30. Gesture Learning and Apraxia
• Abstract
• Introduction
• Material and Methods
• Analyses and Results
• Discussion
• References
• Author Index
• Subject Index