CONDITIONING ANALYSIS OF INFANT LONG-TERM-MEMORY

The long-term retention of conditioned operant footkicks by 3 mo. old human infants was assessed in 2 studies. In both, infants were trained in a conjugate reinforcement paradigm in which footkicks produced conjugate activation of the components of an overhead crib mobile. After 2 training sessions, retention (cued recall, savings) was assessed cross-sectionally in a 3rd session scheduled after varying intervals. In experiment 1, 32 infants were tested after intervals of 48, 72, 96 or 120 h; in experiment 2, 24 infants were tested after 96, 144, 192 or 336 h. No evidence of forgetting was observed for as long as 192 h following original training. Although both retention measures indicated a significant memory deficit in the group tested after 336 h (2 wk), some individuals continued to exhibit substantial recall and savings after this retention interval. A conditioning analysis was viewed as a logical means by which to bridge the gap between animal and adult human models of memory.