Schizokinesis: Fragmentation of performance in two strains of pointer dogs

During the behavior shaping toward bar jumping to avoid shock at the termination of a tone, ten genetically nervous (“E”) and ten stable (“A”) dogs showed different performances in the acquisition of the adaptive motor response. When tested two months later and with concurrent monitoring of their electrocardiograms, these animals also showed differences in (1) baseline heart rate, (2) direction and degree of heart rate change to the conditioned tone stimulus (more often deceleration in the E dogs), and (3) response to the unconditioned shock stimulus. After having performed in an almost satisfactory manner for a few trials, thenervous animals often would suddenly freeze in rigid postures. These animals could frequently be made to emit the adaptive behavior by “breaking the frozen posture” through pushing, jumping, or pulling manipulation. Sometimes a forced righting reflex dramatically encouraged an integrated performance of varying duration. Thestable strain of dogs showed little or none of the rigidity and usually learned the smooth adaptive response. The stable A dogs showed retention of the cardiac Cr, but not of the motor Cr (which they re-formed after one or two reenforcements); the nervous E dogs also retained the cardiac Cr, but persisted in the maladaptive motor performance. The fragmented disorganized behavior in acquiring the adaptive motor act and thedifferential retention of the autonomic and motor responses are considered examples ofschizokinesis as conceptualized by Gantt. This schism is seen in clearer form in behavioral acquisition than in the usual frequency measure of the well-practiced act.