Eye Movements from Physiology to Cognition

Selected/Edited Proceedings of the Third European Conference on Eye Movements, Dourdan, France, September 1985

J.K. O'Regan, A. Lévy-Schoen

• Publisher: North Holland
• Year: 2013
• ISBN:
  9781483290065
• Topic: Psicología
• Subtopic: Psicología cognitiva y cognición

Eye movement research from a range of disciplines is presented in this book. Contributions from all over the world examine theoretical and applied aspects of eye movements, including classical biocybernetic models, physiology, pathology, ocular exploration, reading, ergonomics/human factors, and microcomputer calibration techniques.

Section 1

SACCADE PROGRAMMING

Outline

Chapter 1: SYMPOSIUM INTRODUCTION: THE MODELLING OF SACCADE PROGRAMMING

Chapter 2: DYNAMICS OF SACCADIC TRACKING RESPONSES: EFFECTS OF TASK COMPLEXITY

Chapter 3: THE CHARACTERISTIC PEAK VELOCITY – MEAN VELOCITY OF SACCADIC EYE MOVEMENTS IN MAN

Chapter 4: STIMULUS-INDUCED MIDFLIGHT MODIFICATION OF SACCADE TRAJECTORIES

Chapter 5: THE ROLE OF ATTENTION IN THE PREPARATION OF VISUALLY GUIDED SACCADIC EYE MOVEMENTS IN MAN

Chapter 6: COORDINATED VERGENCE FOR FRONTAL FIXATION, BUT INDEPENDENT EYE MOVEMENTS FOR LATERAL VIEWING, IN THE PIGEON

Chapter 7: KINAESTHETIC AND MOTOR EFFECTS OF EXTRAOCULAR MUSCLE VIBRATION IN MAN

Chapter 8: SPATIAL CODING OF VOLUNTARY SACCADES IN MAN

Chapter 9: DOES THE SACCADIC SYSTEM CONTROL AMPLITUDES OR FINAL POSITIONS ?

Chapter 10: THE SYSTEMATIC UNDERSHOOT OF SACCADES: A LOCALIZATION OR AN OCULOMOTOR PHENOMENON?

Chapter 11: Saccadic Programming With Multiple Targets Under Different Task Conditions

Chapter 12: TWO WAYS OF IMPROVING SACCADE ACCURACY

Chapter 13: ADJUSTMENTS OF HAND POINTINGS TO VISUAL TARGETS DO NOT NEED VISUAL REAFFERENCE FROM THE MOVING LIMB

Chapter 14: VISUAL STABILITY AND DIRECTION OF RETINAL IMAGE DISPLACEMENT DURING EYE MOVEMENT

Chapter 15: SACCADIC EYE MOVEMENTS TO PREDICTABLE VISUAL AND AUDITORY TARGETS

Chapter 16: TWO-DIMENSIONAL SACCADIC AND SMOOTH PURSUIT RESPONSE TO AN EXTRAFOVEAL SMOOTH MOVEMENT

SYMPOSIUM INTRODUCTION: THE MODELLING OF SACCADE PROGRAMMING

John M. Findlay* and Zoi Kapoula**, ^*Department of Psychology, University of Durham, South Road, DURHAM DH1 3LE, England; ^**Laboratoire de Psychologie Experimentale, 28 rue Serpente, PARIS

The previous European Conference on Eye Movements contained a session entitled Properties of the Saccadic Eye Movement System (Gale and Johnson, 1984). This demonstrated that the current capacities for accurate recording of saccadic eye movements and automated analysis of such records have opened up many options for scientific study. The symposium at Dourdan shows that this approach continues to be productive. Indeed the number of papers in the saccade programming symposium was so large that individual mention of all papers in this introduction is regrettably not feasible. Also study of saccadic eye movements forms the basis of much work reported in the Scanning and the Adaptation symposis.

The saccadic eye movement system has attracted the attention of workers in several different disciplines and this can only be welcome in an era of increasing fractionation and compartmentalization of knowledge. Contributions to the symposium come from engineers, physicists, physiologists and psychologists, and it is fitting that several contributors explicitly acknowledge the influence of D.A. Robinson. Robinson, as a physiologist with a background in systems engineering has pioneered the careful harmonization of engineering concepts with physiological findings. In consequence the modelling of the saccadic system that appears in the following pages is much more constrained by the realities of brain function than any comparable modelling in the past. Thus in general, rather than resulting in totally new insights, much work is concerned with fleshing out details and redressing the unfortunate overemphasis on horizontal saccades in earlier studies.

What is the physiological basis on which saccadic modelling now stands? We know, through the work on single unit recordings in animals (see e.g. Fuchs, Kaneko and Scudder, 1985), that certain cells in the brainstem are normally active but switch off for each and every saccade – the omnipauser cells. We know in turn that when these cells switch off, burst cells are released from inhibition, or at least a selection of burst cells since these, in contrast to the omnipauser cells, selectively code the spatial properties of the saccadic movement. Above all we know, following the work of Robinson (1975, 1981), how the burst cells can direct the appropriate firing in the motoneurons to move the eye and hold it in position. Thus the basic pulse generation system can be regarded as well established, although one of the most significant developments in recent years has been the demonstration by Fischer’s group of different categories of saccades based on measures of latency distributions. These presumably reflect different points in time at which the pulse generator may be activated. Several papers address the issue of whether there might be more than one pulse generator, notably those by van Gisbergen, van Opstal and Roebroek, and the impressive study on the pigeon by Bloch, Lemeignan and Martinoya. Properties of the pulse generator also form the basis of the paper by Inchingolo, Spanio and Bianchi, and the posters by Galley, by Kapoula, Robinson and Hain, and by Bour, de Veth and Huygen.

Another idea introduced by Robinson was that the control of burst cells to move the eye to the target position was achieved by a local feedback loop using instantaneous eye position information. Several of the papers are concerned with the details of how this might be implemented and the general idea of a spatiotopic framework for saccade planning is discussed below in connection with predictive eye movements. Van Gisbergen et al provide further confirmation, in a very striking way, that saccades trajectories are modifiable in a target-seeking manner. Viviani and Velay carry out a psychophysical study which parallels the informative demonstration by Mays and Sparks (1980) that saccade control uses a spatiotopic signal, and the paper by Ling relates to the same issue. Roll and Roll introduce the technique of muscle vibration to discover properties of the extraocular muscle system. The partial stabilization technique of Barabanschikov shows that a bizarre form of interference with voluntary eye movement can be created when the relationship between the direction of movement of the eye and contingent direction of retinal motion is changed. However, it is interesting that small changes in this relationship pass unnoticed.

Moving upwards from the brainstem circuitry that generates the movement itself, psychophysical studies in the posters by Asten and Gielen and by van der Wildt, Flipse, Rodenburg and Keemink examine the properties of the visual system in relation to eye movements. The poster by Accardo, Inchingolo and Pensiero enriches our knowledge of the relation between latency and size of the movement which is often thought to be due to visual processing.

Amongst psychologists, saccadic eye movements are usually seen as a means rather than an end and interest focuses on their role in perception and cognition. In the area of perception particularly, the elegant work of oculomotor modellers and experimenters, along with other work in neurobiology, has currently to face criticisms from a movement, associated with the writings of J.J. Gibson (1966, 1979), which queries the relevance of laboratory based studies for understanding perception in real world environments. We believe that this attack is largely unjustified and that work in eye movements has been more sensitive than in some other areas to the biological nature of the system under study, for example in the recent emphasis on adaptive properties of oculomotor control.

Nevertheless it is necessary to be vigilant. It is easy to forget that eye movements did not evolve to scan display screens. Certain things are immediately evident when consideration is given to ‘real world’ eye movements. The three dimensional nature of visual space is paramount and this has the consequence that the normal visual input to the saccadic system is different in two respects from that usually considered by systems modellers. Firstly, sharply focused, small targets are unlikely to occur frequently. Secondly, targets at a different depth from the original fixation plane will show disparity; that is the retinal error signal in the two eyes will differ. When this is borne in mind, it is not too surprising that the saccadic system shows the spatial integration of the visual input found in the global effect (Findlay, 1982; Ottes, van Gisbergen and Eggermont, 1984).

Gibson’s ambition to explain perceptual systems with no reference to cognitive process sometimes drove him to absurd lengths when he discussed eye movements. His claim (Gibson 1966, p.260) that shifts of fixation can be attributed to “interesting structures in the array and interesting bits of structure” answers very little. Saccadic eye movements provide an unrivalled opportunity for psychologists to investigate the microstructure of cognitive activity (or whatever name is given to the process which allows what is ‘interesting’ to change from moment to moment). Much of the material on cognitive control of saccades is to be found in other symposia but two papers (Coëffé and Menz and Groner) examine th...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• PREFACE
• Section 1: SACCADE PROGRAMMING
• POSTERS on Saccade Programming
• Section 2: ADAPTABILITY IN THE OCULAR-MOTOR SYSTEM
• POSTERS on Adaptability
• Section 3: VISUAL SCANNING: DESCRIPTION AND THEORY
• POSTERS on Visual Scanning
• Section 4: EYE MOVEMENTS, LEXICONS, AND LANGUAGES
• POSTERS on Lexicons and Languages
• Section 5: THE USEFULNESS OF EYE MOVEMENTS IN ERGONOMICS AND APPLIED SCIENCES
• Section 6: MEASUREMENT TECHNIQUES
• POSTERS on Measurement Techniques
• AUTHOR INDEX
• SUBJECT INDEX