The Development of Action Sequences

Many years ago, [Lashley (1951)] challenged behavioral neuroscientists to examine movement properties and the serial order of behavior more specifically. This was in many respects a logical follow-up of [Hebb’s (1949)] concerns with the organization of behavior, according to which, individual behavioral and brain properties must be isolated, but also examined within broader contexts of expression ([Fentress, 1999]). For example, Hebb devised concepts of cell assembly and phase sequence to help behavioral neuroscientists evaluate the fact that all behavior is organized in time. Movement is a directly observable manifestation of this dynamic ordering in brain and behavior ([Berridge & Whishaw, 1992]; [Fentress, 1990], [1992]; [Golani, 1992]; [Kelso, 1997]; [Thelen & Smith, 1994]). As such, quantitative analyses of movement can provide fundamental insights into brain—behavior organization, including the developmental profiles that occur dynamically across levels and time frames of operation. As stated by [Churchland and Sejnowski (1992], p. 178), “Our brains are dynamical, not incidentally or in passing, but essentially, inevitably, and to their very core.” As will become clear in this chapter, we agree with this position, and believe that action dynamics can provide fundamental insights into processes at both onto-genetic and integrative time frames of organization