Functional Systems and the Mechanisms of Behavior
Although the ecological analysis of behavior and awareness offered so far has emphasized the habitat-limited nature of many animal activities, it has also suggested a basis for theorizing in a more general way about mechanisms for the regulation of awareness and behavior. In particular, the evolution of neural control of behavior has always been characterized by a striking contrast between the functional need of animals to regulate their activity in terms of persisting features of the environment and the relatively impermanent nature of most behavioral units. Because of this contrast, successful behavioral regulation cannot occur without mechanisms capable of organizing the very short-term and small-scale events of the neuromuscular system (measurable in fractions of seconds and millimeters or less) into ecologically meaningful patterns (measured in multiple seconds and meters or more). The theory of affordances, the theory of information, and the analysis of persistence and change in the environment presented in earlier chapters thus offer an opportunity for providing an evolutionary and ecological explanation of the neural mechanisms of behavior.
Ecologically meaningful action patterns typically cannot be assembled in a fixed manner because of the intrinsically variable nature of all habitats. A system that organized neuromuscular activity, but did so inflexibly, could not survive in the real world. Not every leaf can be pulled into a worm's burrow from the same locus. However, as I have also emphasized, the crucial issue concerning regulatory organization is not merely flexibility but functional specificity--the ability to monitor, track, and adjust to significant variations in one's circumstances. It is not enough to account for flexibility or plasticity, as modern neurophysiological theories attempt to do. There needs to be some way of tying this plasticity to environmental circumstances, some way of describing and explaining the functional specificity of behavioral processes. The worm's goal is not to grab every leaf at a special place, but to grab all leaves by a place that best affords using it to plug one's burrow. Given this, the neural mechanisms underlying behavioral regulation have to be organized ecologically, over spatiotemporal grains that link behavioral units to functional sequences, and link those sequences to the significant encounters of the organism with its surroundings throughout its life cycle. Hence, neural mechanisms for regulating behavior are under intense selection pressure to locate and use