REVIEW
Visuo-motor coordination and internal models for object
interception
Myrka Zago Æ Joseph McIntyre Æ Patrice Senot Æ
Francesco Lacquaniti
Received: 12 September 2008 / Accepted: 25 November 2008 / Published online: 13 January 2009
Ó Springer-Verlag 2009
Abstract Intercepting and avoiding collisions with mov-
ing objects are fundamental skills in daily life. Anticipatory
behavior is required because of significant delays in trans-
forming sensory information about target and body motion
into a timed motor response. The ability to predict the
kinematics and kinetics of interception or avoidance hun-
dreds of milliseconds before the event may depend on
several different sources of information and on different
strategies of sensory-motor coordination. What are exactly
the sources of spatio-temporal information and what are the
control strategies remain controversial issues. Indeed, these
topics have been the battlefield of contrasting views on how
the brain interprets visual information to guide movement.
Here we attempt a synthetic overview of the vast literature on
interception. We discuss in detail the behavioral and
neurophysiological aspects of interception of targets falling
under gravity, as this topic has received special attention in
recent years. We show that visual cues alone are insufficient
to predict the time and place of interception or avoidance,
and they need to be supplemented by prior knowledge (or
internal models) about several features of the dynamic
interaction with the moving object.
Keywords Motor control Á Timing Á Motion perception Á
Neural delays Á Cerebellum Á Insula Á
Temporo-parietal cortex
Introduction
‘‘We may have knowledge of the past, and cannot control
it. We may control the future, but have no knowledge of
it’’ (Shannon 1959). The attempt to predict what stimuli
will be sensed in the future represents an evolutionary
response of the brain to the time’s arrow associated with
entropy increases of irreversible processes (time is uni-
directional). An organism that can predict accurately is
able to plan a response to foreseen events, while one that
cannot predict can only react after the event. Moreover,
purely reactive behavior may be rendered useless by the
sensory-motor delays; neural transmission, muscle force
generation and effector inertia, each contribute consider-
able time delays.
Whether an object is moving (object-motion) or we are
moving (ego-motion), often we must be able to predict
several hundreds of milliseconds into the future whether,
when and where an impending collision may occur. We
must rapidly decide what we want to do and act appro-
priately, by planning either an interceptive action to
achieve a desired capture of the target or an evasive action
to avoid an unwanted collision with it. Catching or hitting a
flying ball, jumping over an obstacle, landing from a fall or
diving in water, crossing the road, braking a car are just a
M. Zago Á F. Lacquaniti (&)
Laboratory of Human Neurophysiology,
IRCCS Santa Lucia Foundation,
University of Rome Tor Vergata,
via Ardeatina 306, 00179 Rome, Italy
e-mail: lacquaniti@caspur.it
J. McIntyre Á P. Senot
Laboratoire de Neurobiologie des Re
´
seaux Sensorimoteurs,
CNRS, Universite
´
Paris Descartes, 45 rue des Saints Pe
`
res,
75270 Paris, France
F. Lacquaniti
Department of Neuroscience, University of Rome Tor Vergata,
Via Montpellier 1, 00133 Rome, Italy
F. Lacquaniti
Center of Space Biomedicine, University of Rome Tor Vergata,
Via Montpellier 1, 00133 Rome, Italy
123
Exp Brain Res (2009) 192:571–604
DOI 10.1007/s00221-008-1691-3