Classical Conditioning in Newborn Rats

Associative learning was evaluated in human infants with simple delay classical eyeblink conditioning. A tone conditioned stimulus (CS) was paired with an airpuff unconditioned stimulus (US) at three different delay intervals (250, 650, and 1,250 ms). Independent groups of healthy, full-term 5-month-old human infants were assigned to these three paired conditions and received two identical training sessions 1 week apart. The two longer delays resulted in associative conditioning, as confirmed by comparison with unpaired control groups. However, only at the 650-ms delay were associative eyeblinks adaptively timed to avoid the airpuff. The delay function at 5 months of age appears much sharper than is observed in adults. Together with the findings of A. H. Little, L. P. Lipsitt, and C. Rovee-Collier (1984), the present study suggests a downward shift in the optimal delay interval for associative eyeblink conditioning between 1 and 6 months of age. However, this delay remains longer than what is typically reported in adults.

Section: Discussionmentioning

confidence: 91%

Effect of delay interval on classical eyeblink conditioning in 5‐month‐old human infants

Claflin

Stanton

Herbert

et al. 2002

“…Although some developmental differences exist, both species are undergoing rapid dendritic growth of the cortex, are approaching adult thickness of the cortex, and are beginning to demonstrate adult-like EEG patterns (Himwich, 1962;Kobayashi, Inman, Bufio, & Himwich, 1963) during the period in which 24-hr retention of the escape task develops. However, it should not be surprising to find that memory for less coniplex responses, such as a classically conditioned leg withdrawal 268 NAGY, MISANIN, AND OLSEN (Caldwell & Werboff, 1962), would develop earlier than 9 days of age, whereas memory capacity for more complex responses, such as would be required in a discrimination avoidance task, would emerge at a later age. Until further research is conducted, the findings of the present study should be regarded as the development of a memory capacity for a specific response rather than to the development of memory per se.…”

Section: Discussionmentioning

confidence: 99%

Development of 24 hour retention of escape learning in neonatal C3H mice

Nagy

Misanin

Olsen

1972

Selinsgro ve, Pen ns y 1 van iaThe development of 24-hr memory of an escape response in neonatal C3H mice was examined in 2 experiments. In experiment 1, separate groups of mice received 25 trials of escape training for 3 consecutive days (24 hour Inter-session-interval) beginning at 5, 7, and 9 days of age. Several different measures demonstrated within-session improvement for all ages on all test days. However, between-session improvement which was not due to maturation did not occur until after 9 days of age. In experiment 2, separate groups of mice received 25 escape training trials at either 8 or 10 days of age, and were retested 24 hrs later. Comparisons of the retest scores with original training scores as well as with littermate controls without prior training experience, showed that 8-day old mice failed to show retention effects of prior training, whereas 10-day old mice performed better on the retention test than they had on original training, as well as better than controls without previous training. The results suggest that 24-hr memory of the escape task develops at 9-10 days of age in the C3H mouse.The ability of neonatal rodents to show improved performance in a relatively simple escape task has recently been reported for mice (Nagy, Misanin, & Newman, 1970; Nagy, Misanin, & Olsen, 197 1) and rats (Misanin, Nagy, & Weiss, 1970) as young as 5 days of age. Several measures of performance suggested improved escape behavior by the end of the training session for both species. However, although the 5-day old rat appears to show within-session learning, the ability to retain the improved performance level for a 24-hr period does not occur until 9 days of age Wisanin, Nagy, Received for publication 11 August 197 1 Development Psychobiology, 5 ( 3 ) : 259-268 ( 1 972)

“…A growing body of evidence suggests that such forgetting may be greater in immature than in mature organisms (e.g., Campbell & Coulter, 1976;Campbell & Spear, 1972). This enhanced forgetting by immature animals, including humans, has been termed "infantiIe amnesia.…”

mentioning

confidence: 97%

Alleviation of forgetting in preweanling rats

Spear

Smith

1978

Three experiments tested the learning and retention of neonatal rats (7, 9, and 12 days of age) with a nondirectional active avoidance task, using a vibrotactile conditioned stimulus. The hypothesis was that the substantial deficit of these animals in 24-hr retention is due, at least in part, to a deficiency in memory retrieval. In Experiment I, a reactivation treatment was found to alleviate the forgetting over the 24-hr period for 12-day olds although having somewhat lesser effect for animals 9 days of age. The reactivation treatment seemed ineffective for rats 7 days of age. Experiments II and III confirmed the reliability of the reactivation effects with 9- and 12-day olds, while adding further control conditions and providing new information concerning the ontogenesis of latent inhibition.