The Effect of Instrumentalization of Inborn Reaction

Transformation of inborn reaction of leg flexion into conditioned escape response of leg extension was studied. The model of the so called precise reflex was used. A dog could avoid or escape the shock applied to the paw by placing this paw in a narrow ,,safety zone" located at a definite height above the floor. When the shock is applied to the paw located below this zone, the escape response is flexion, i.e., it coincides with the inborn reaction. When the paw is lifted above this zone, the escape response is extension, i.e., it is opposite to the inborn response. Success of such extension response acquisition depended on the sequence of training conditions. The dogs of Group I at the beginning were accustomed to escape from shock by lifting the paw into the ,,safety zone", i.e., inborn reaction was instrumentalized. A subsequent formation of conditioned extension was extremely difficult and it did not became strong in spite of a very long training. Lowering the paw into the ,,safety zone" was usually slow. The dogs of group I1 were trained from the very beginning to escape from shock by leg extension. Contrary to the results obtained on group I this conditioned response was perfectly established. It was formed rapidly, only when active extension was paired regularly with termination (during extension) of the shock. It is suggested that conditioned connection from one functional center to another is formed and becomes stronger if evoked activity of the first center decreases during (or immediately after) the excitation of the second center. It is known that the transformation of a conditioned reflex into an antagonistic conditioned reflex is difficult as compared to initial conditioning (5). But is was not clear whether the transformation of inborn motor excape reflex into an antagonistic conditioned escape response was also being impeded. In the experiments of Stul (9) an escape response directly opposite to inborn reflex was formed in dogs in the course of precise avoidance reflex training i.e., lifting the paw into a narrow "safety zone" (SZ). When the subject lifted its paw above the SZ by mistake, a painful electrical stimulation (ES) was applied to it and the animal had to ldwer paw into the SZ to escape from shock. Such escape (opposite to inborn) responses (EORs) 'were formed with extreme difficulty. The purpose of the present work was to investigate the relative role of different factors which interfered with the acquisition of the EOR in the course of the precise reflex training.