The signal-flow diagram of the oculomotor control system,--and its transferability to the more intricate skeletomotor control system.

Abstract

A signal-flow diagram of the oculomotor control system has been derived which is able to describe the three modes of its action 1) pursuit movements 2) voluntary saccadic movements and 3) the passive non-innervated state of extraocular muscles which exists during sleep. It has been taken into consideration that in the smooth pursuit system there is a neural integrator in order to bring back to zero the error between the position of the eye and an external constant reference point. [Evidence for integration in oculomotor pathways we have from experiments by Cohen and Komatsuzaki (1972) who used stimulation of the pontine reticular formation.] All this is achieved by a system of variable structure with three states. In skeletomotor systems likewise there are smooth compensatory movements and voluntary movements and a state without any innervation. Some neurological diseases can be interpreted as an impairment of switching at special spots of the signal-flow diagram or as a disconnection of signalpathways, respectively. From this can be concluded that the signal-flow diagram derived for the rather lucid oculomotor control system should be able to describe the basic function of skeletomotor control systems, too.