J. A. Scott Kelso Haskins Laboratories and The University of Connecticut
When one thinks about it, much of this book has to do with questions of the following type: When animals and people move about in their environment in an apparently purposeful fashion, what is lawful about their behavior? And, if there are identifiable, law-like regularities in their acts, how do we--as students of motor behavior--understand them?
In the early chapters of the book there is represented a single set of solutions to these questions. Such solutions revolve around hypothetical constructs like the perceptual traces, reference mechanisms, and comparators that are common in cybernetic, closed-loop systems, or the motor programs and schemata that have their origins in computer technology. We can call this set of solutions "artifactual," in the sense that acting humans are compared to machines (servomechanisms and computers) provided with means of control and regulation. I think it is quite clear that this class of model has dominated research and thinking in the 1970s and is certainly well-represented in the chapters by Stelmach, Schmidt, and Keele. Along with promoting a great deal of laboratory activity, the artifactual approach has allowed us to conceptualize the underlying "processes" that may guide human activity. I have little doubt that the artifactual approach will continue to play a major role in movement science for many years to come. It embodies many attractive features that appeal to the scientist, not least of which as is its apparent testability. Questions like: Is feedback important?; which modality (vision or proprioception) is more powerful for regulating activity?; are recall and recognition fundamentally different motor memory processes?; what is "contained" in the motor program?; how abstract is a motor