Conditioning and long-term memory in three-month-old infants with Down syndrome.

The learning and memory of twenty 3-month-old infants with Down syndrome was compared with that of 20 infants without handicaps using an operant conditioning task known as mobile conjugate reinforcement. The infants were trained for 2 days to produce movement in an overhead crib mobile by kicking and were reexposed to this task a week later. Both groups successfully acquired the contingency and displayed reliable long-term retention. In addition, the conditioning and retention-test performance of the two groups of infants did not differ.