Crying and retrograde amnesia in young infants

Abstract

The delay gradient associated with crying-produced retrograde amnesia in infants was investigated using an operant conditioning paradigm. Three- to 4-month-old infants learned to produce movement in an overhead crib mobile containing 10 identical components and were switched to a mobile containing only 2 components during a third daily session. Independent groups of infants experienced delays of 0, 2, 5, 15, or 30 min between mobile switches. Infants who cried in response to the shift in mobiles when the interval between exposure to the two mobiles was between 0 and 15 min but not 30 min failed to show evidence of retention 1 week later. The relation between the preshift/postshift delay interval and retention test performance in the crying infants was linear. In contrast, non-crying infants in all groups continued to respond above operant level during the 1-week retention test. The existence of this retrograde amnesia gradient for crying is consistent with that seen for other amnesic agents and supports the view that infant forgetting results from a retrieval failure engendered by a lack of consistency between the contexts present at the conclusion of a learning experience and during the long-term retention test.