Methodological problems in conditioning the headturning response of newborn infants

Abstract

Forty newborn infants received tactile stimulation to the cheek, followed by glucose solution which was either contingent (Experimental Ss) or noncontingent (Control Ss) upon an ipsilateral headturn. Treatment groups were subdivided into No-Drug or Drug groups, on the basis of medication given to mothers in the 4-hr period preceding delivery. Results indicated no main effect of maternalmedication. There was a main effect of Treatment, with Experimental Ss responding with more headturning than Control Ss. The Experimental Ss did not maintain their increased responding throughout trials, but tended to return to the Control group's level of responding toward the end of conditioning. When Ss were categorized into subgroups on the basis of state of wakefulness when entering the experimental room, “awake” Ss proved to be significantly more responsive than did “asleep” Ss. All Ss had experienced a wake-up procedure in order to control for arousal state at the beginning of conditioning. However, those Ss spontaneously awake showed more headturning throughout the session than did those Ss initially rated asleep, but rated awake after the wake-up procedure. In discussing the discrepancies between this study and previous conditioned headturning studies by Siqueland and Lipsitt (1966), the authors noted that Ss in the earlier work had all been spontaneously awake, and that a smaller headturn was reinforced than in the present study.