Chapter 3 Kinds and Levels of Explanation: Implications for the Motor Systems Versus Action Systems Controversy

Abstract

Summary With respect to motor control and learning two theoretical approaches are distinguished. One, the motor systems approach, is characterized by the use of information processing models and hypothetical constructs framed in cognitive terms. Such models and constructs are rejected by proponents of the second approach. The latter, action systems approach, is inspired by Gibson's work. Two kinds of action systems theories have been developed, a 'Gibsonian' one (e.g., Reed), and a 'Neo-Gibsonian' one (e.g., Kugler). The Gibsonians try to explain motor behaviour as a function of information specifying the environment, the Neo-Gibsonians resort to physical principles guiding the behaviour of energy consuming open biological systems. In discussing Gibson's ecological psychology attention is drawn to its strong behaviouristic (Skinnerian) overtones. Analogies between Gibson's and Skinner's theorizing are pointed out, in particular with regard to their rejection of 'mentalistic' constructs and their scepticism about neurophysiological explanations of behaviour. It is argued that the significance of Gibsonian types of action theories, in sticking to the ecological level of description and in eschewing explanations in terms of processes at other (psychological or physiological) levels of description, is limited to situations exhibiting a perfect fit between organism and environment. Consequently the Gibsonian approach falls short in accounting for human motor learning processes, where, at least initially, such a perfect fit does not exist. Although the explanatory power of the Neo-Gibsonian theories is judged to be greater than that of the Gibsonian ones, the former also seem to be incapable of addressing human learning i n a fruitful way. Therefore, action systems theories leave many phenomena unexplained, phenomena which are addressable (and are indeed discussed) in motor systems theories. It is argued that not only neurophysiological explanations but also psychological explanations, making use of cognitive constructs, are admissable from a methodological viewpoint and can shed light on human motor behaviour. A reconciliation of the different viewpoints characterizing, the motor and action system approaches is deemed possible, as well as worthwile.