Cortical inhibition hypothesis

Associated with reflexology, it seemingly originated with the founding father of British neurology John Hughlings Jackson (1835-1911) and his idea of physiological inhibition or encephalization based on the brain possessing a hierarchical organisation such that ‘higher’ centers (i.e., the cortex) suppressed the expression of behaviors assumed to be controlled by lower’ centers (i.e., sub-cortical structures like the brain stem and spinal cord).  Applied to development, it holds that earlier appearing behaviors (e.g., reflexes) are tonically inhibited by the emerging influences descending from the newly developing cortex, and in this way voluntarily-controlled actions emerge.  In adult neurology, it was used by Jackson to account for the disappearance of reflexes under pathological conditions and is a reason why the hypothesis is inappropriate for the study of normal development.  Other problems when applied to development, as for example by Davenport Hooker (1887-1965), include knowing the fate of the suppressed behaviors and that cortical influences are only depicted as having inhibitory functions and not excitatory ones as well.  Still has its adherents in infant developmental research, but its influence is on the wane as we begin to understand better the complex and reciprocal interactions between the functions of cortical and sub-cortical structures during development.

See Hierarchical models of motor control, Motor control, Reflex, Reflexology, Stepping response