The MUCOM Action aimed to answer the following questions:
-On what does the integration of sensory signals depend, considering the multimodal perception of space and movement in natural systems?
-What is the common frame of reference into which all sensory inputs are translated?
-How does the brain incorporate the geometric and dynamic properties of motor systems in order to elaborate movement command strategies?
-Considering the flexibility of the human and animal motor system, what strategies are used to control the execution of movement?
-How does information on simple motor effectors (such as the eye) compare with information about complex ones (like the head)? And what general principles underly these mechanisms?
Greater understanding is sought of how the brain builds an internal representation of space and movement in order to allow navigation, orientation and action. This objective involves studying the questions of fusion of sensors, sensorimotor coordination, movement perception, posture control and limb movement in biological systems.
The research focussed on 3 areas, navigation, orientation and action, and gave the following results:
measurement of 3-dimensional eye or head movement using magnetic fields;
design and industrial realization of multisensory (visual and vestibular) stimulators;
new histological techniques for marking neurons and the study of really neuronal networks (intracellular and extracellular);
manipulation of visual flow fields (computer displays of visual flow fields for optimizing 3-dimensional motion perception);
algorithms for optimization of multilimb manipulators;
simplifying principles for control 3-dimensional mechanical devices (Listing's law);
new control principles for visiomotor orienting using visual maps with dynamic remapping properties by velocity or position feedback (neurophysiological evidence for existence of feedback in biological systems);
comparative, computer implemented models for active orienting mechanisms;
discovery of the use of extraretinal binocular feedback for the perception of depth;
new results concerning the use of inertial signals for navigation;
basic algorithms underlying visiomotor relations.
APPROACH AND METHODS
Research focused on three areas:
-Navigation, looking at multisensory interaction in the generation of stabilising eye and head movements, the multisensory detection of head movement, the generation of motor output, and problem-solving strategies. The methods used were behavioural and e lectrophysiological experiments on movement stabilisation, and electrophysiological studies on curvation estimation in navigation trajectories. Theoretical models were also to be constructed.
-Orientation, which is concerned with multisensory integration, sensorimotor integration and calibration in the control of orienting movements. Investigations were made into: internal target representation and coding of eye position; premotor mechanisms(activity patterns and neuronal connectivity); and sensorimotor transformations. Anatomical and electrophysiological studies of the relevant systems were to be performed.
-Action, centred on sensorimotor coordination in the control of the human upper limb. This part of the research will address representations of limb configurations, algorithms for limb coordination, and control mechanisms. These aspects were to be invest igated by recording the position of several limb joints via opto-electrical methods and by studies of task execution concerning visuo-manual coordination in humans.
PROGRESS AND RESULTS
-Measurement of three-dimensional eye or head movement using magnetic fields (commercially available)
-design and industrial realisation of multisensory (visual and vestibular) stimulators (commercially available)
-new histological techniques for marking neurons and the study of really neuronal networks (intra- and extracellular)
-manipulation of visual flow fields: computer displays of visual flow fields for optimising 3D object motion perception
-algorithms for optimisation of multilimb manipulators
-simplifying principles for control of 3D mechanical devices (Listing's law)
-new control principles for visio-motor orienting using visual maps with dynamic remapping properties by velocity or position feedback. Neurophysiological evidence for existence of feedback in biological systems
-comparative, computer-implemented models for active orienting mechnisms
-discovery of the use of extraretinal binocular feedback for the perception of depth
-new results concerning the use of inertial signals for navigation
-basic algorithms underlying visio-motor relations
1.Robotics: principles for multi-limb manipulators and mobile robot navigation; algorithms for active vision and orienting.
2.Biomedical methods: new methods and criteria for the study of neurological otorhinolaryngological or ophthalmological diseases.
3.Ergonomics: potentially useful information concerning the rules governing perception of motion on visual displays and visuo-motor coordination.
4.Telecommunications: potentially useful principles for preventing degradation of 3D motion information and retrival after image compression; principles for simplifying image, retaining the perception of curvature of 3D objects.
6525 EZ Nijmegen