Childhood Amnesia and Episodic Memory: A Developmental Perspective

Abstract

The phenomenon of childhood amnesia has been well-documented over the last century; in general, adults are unable to recall events that occurred during their infancy and early childhood. Although researchers have proposed a wide variety of theoretical accounts, the specific mechanism responsible for childhood amnesia is unknown. One theory of childhood amnesia involves the development of episodic memory. The term episodic memory is used to refer to the recollection of personal, past experiences. Tulving (1972, 1983) originally coined the term; he argued that episodic memory is memory for information about the what, when, and where components of an event. More recently, Tulving (1985, 2002a, 2005) has also argued that episodic memory is accompanied by autonoetic consciousness. The critical distinction of autonoetic consciousness is that the individual must remember something that happened to him or her in the past and not simply know that it happened. Tulving has argued that episodic memory skill is a uniquely human ability. Within the context of childhood amnesia, Tulving has also argued that infants and children under the age of 4 years lack the ability to form episodic memories, which renders them amnesic for events that took place during their infancy and early childhood. Although this theory has been widely accepted in the psychological literature, there is no empirical evidence to support the notion that young children are incapable of autonoetic consciousness and episodic memory.

The experiments presented in this thesis were designed to examine episodic memory in young children. In Experiment 1, a new Timeline procedure was developed to directly compare the age and density of the early memories reported by children, adolescents, and adults. Overall, the proportion of memories reported before the age of 3 years was greater for the children and adolescents relative to the adults. In addition, the single earliest memory reported by children and adolescents was younger than that reported by adults. Importantly, regardless of the age of the rememberer, participants’ early memories had the same episodic and autonoetic characteristics.

Experiments 2 and 3 involved a prospective design that provided the opportunity to eliminate alternative interpretations of the results of Experiment 1. Young children were tested using an operant train procedure originally developed by Rovee-Collier. Children’s verbal recall of the event was assessed after a 24-hour delay (Experiment 2) and after a 1-year delay (Experiment 3). Irrespective of the delay, children reported a large amount of information about the event. In addition, after both delays, children provided a significant amount of autonoetic, episodic information about their memories of the train event.

In contrast to Tulving's account of childhood amnesia, the results of the present experiments indicate that children as young as 3 are able to encode episodic information and to report that information when they are tested after a significant delay. Although children and adolescents retain access to these very early episodic memories (at least during childhood), they are eventually forgotten. Clearly, childhood amnesia cannot be explained by an inability to form episodic memories early in development. Instead, children’s growing ability to use language to encode, store, and retain fuller representations of their episodic memories may make their memories less susceptible to forgetting over the long-term.