Chapter 1: Introduction
Understanding human motor control
One understands a system if one can predict and control it. It is possible to demonstrate one’s
understanding of a system by simulating it. In the case of motor control, such a simulation can take
the form of a robot that moves in a way that is indistinguishable from the way neurologically normal
people do. Such a robot would pass a Turing test of motor intelligence.
Levels of analysis
David Marr proposed three levels of understanding for the study of robotic systems that simulate
human motor control. The understanding of human motor control requires work at all three levels,
no level is more important than the others.
i. Computational level: consists of a description, often expressed mathematically, of one
or more functions that a system is supposed to achieve. Even if equations are not used
explicitly, they are used implicitly in performance. The computational level of analysis is
concerned with those implicit equations.
a. If this level were excluded, most efforts to advance robotics would be abandoned.
ii. Procedural/algorithmic level: behavioural and cognitive states. This level concerns
events that occur in real time. Not actually algorithmic, since algorithms are guaranteed
to work.
a. If this level were excluded, most studies of effective training procedures would be
left by the wayside, as would research in the field of human factors.
iii. Implementation level: it is important what procedures are permitted to be physically
achieved.
a. If this level were excluded, most medical conditions involving motor control would
be forgotten.
Understanding human motor control
One understands a system if one can predict and control it. It is possible to demonstrate one’s
understanding of a system by simulating it. In the case of motor control, such a simulation can take
the form of a robot that moves in a way that is indistinguishable from the way neurologically normal
people do. Such a robot would pass a Turing test of motor intelligence.
Levels of analysis
David Marr proposed three levels of understanding for the study of robotic systems that simulate
human motor control. The understanding of human motor control requires work at all three levels,
no level is more important than the others.
i. Computational level: consists of a description, often expressed mathematically, of one
or more functions that a system is supposed to achieve. Even if equations are not used
explicitly, they are used implicitly in performance. The computational level of analysis is
concerned with those implicit equations.
a. If this level were excluded, most efforts to advance robotics would be abandoned.
ii. Procedural/algorithmic level: behavioural and cognitive states. This level concerns
events that occur in real time. Not actually algorithmic, since algorithms are guaranteed
to work.
a. If this level were excluded, most studies of effective training procedures would be
left by the wayside, as would research in the field of human factors.
iii. Implementation level: it is important what procedures are permitted to be physically
achieved.
a. If this level were excluded, most medical conditions involving motor control would
be forgotten.
