Concluding remarks to section I top-down versus bottom-up approaches to connect cognition and somatic motor sensations

Chapter 3 highlighted the contributions of cognitive theories to autism research. The cognitivist ideas reviewed in the chapter provide a top-down approach to the possible relations between cognition and movements. Despite its relevance to help us formulate questions regarding motor control differences in autism spectrum disorder (ASD), the top-down approach tends to obstruct our ability to bridge cognition and action in neurodevelopment. This is, in part, due to a reliance on descriptions of a system that, although still young and growing, has already reached a steady-state rate of development. The system of a 5-year-old child or that of a young adolescent is physically growing at a steadier pace than that of a newborn baby. Indeed, the steady-state growth of a child stands in stark contrast to the rapid rate of growth of the nascent nervous systems of a newborn baby. The latter is changing on a daily basis at highly accelerated rates (Figure I.1). To better appreciate this difference, consider, for example, the rate of physical growth of a newborn baby. In 30 days, the body gains weight at a nonlinear rate of change that varies from 0.02 kg/day to nearly no change to actual weight loss in the first week (Figure I.1). If we were to apply such rates to the body of a 5-year-old child, the changes would be, even overnight, so appreciable to the child’s brain that a total “recalibration” of all bodily and sensory maps would be required for that brain to be able to control that body from one day to the next. Indeed, Figure I.1c shows that the typical 5-year-old child (1825 days) changes weight at a rather slower rate per day in relation to the newborn baby.