On the Construction and Perception of Complex Movements

The third lecture will focus on the control of complex movements. In recent years different lines of evidence have led to the idea that motor actions and movements in both vertebrates and invertebrates are composed of elementary building blocks. The entire motor repertoire can be spanned by applying a well-defined set of operations and transformations to these primitives and by combining them in many different ways according to well defined syntactic rules. Motor and movement primitives and modules may exist at the neural, dynamic and kinematic levels with complicated mapping among the elementary building blocks subserving these different levels of representation. I will describe different approaches to movement decomposition and the extraction of motor primitives and demonstrate their application to human, primate and octopus movements. I will also discuss studies showing how kinematic laws of motion and spatial and temporal invariants characterizing biological motion may constrain action-perception coupling. Finally I will discuss the topic of body expression of emotion by describing possible building blocks subserving the postural and motor expression of emotion.