The more rapid forgetting of memories during infancy than later in development. It was Sigmund Freud (1856-1939) who put forward the idea that infant amnesia amounts to a suppression of any early traumatic events of experiences. In a seminal paper published in 1996, Carolyn Rovee-Collier rightly stressed that it is not only based on anecdotal evidence, but that it was “… an effort to explain a phenomenon that does exist.” (p. 367). Her own programme of research on infant memory has made important contributions to challenging this simplistic portrayal of infantile amnesia. Since 1996, there has been much speculation about its particular function. Broadly speaking, there are two theoretical interpretations about infantile amnesia. One is that the memory loss is due to a storage problem such that early experiences do not become functionally transformed into long-term memories. And it does seem strange that adults have only a few recollections of early childhood despite the fact that they engage in very active forms of learning. Perhaps this not surprising given that, for example, objects may appear much larger and offer different affordances than is the case for adults. Another interpretation holds that the sort of memory under consideration is a retrieval problem. Neuroscientific interpretations as to why infants may not recall events later in life have arisen in recent years based on evidence that the neural circuitry of the brain has not become full functional. One candidate is the hippocampus, because of its role in memory, especially declarative memory in animal research. A hypothesis implicating the hippocampus rests on findings, also from animal studies, and on the fact that infants exhibit high levels of hippocampal neurogenesis (together with an inability to form lasting memories). The key to to hypothesis is that high neurogenesis levels dysregulate the ability to form enduring memories, probably as a consequence of synaptic connections being replaced in already existing hippocampal circuits. Then there is associated hippocampal restantiation theory, originally applied to adults, suggesting that infant memories may indeed exist, but cannot be recalled or retrieved due to the extensive pruning that takes place throughout the neocortex during early childhood. Consequently, inaccessibility and than a lack of retention is responsible for the lack of memories during early life. Other cortical structures that are receiving increasing as to the role they play in the early development of memory are the frontal cortex and the inferior temporal cortex. The current emphasis on multiple memory systems derives from the assertion that such systems are controlled by different brain systems, for example, between the conscious recollection of experience (declarative memory) and unconscious memories of habits and skills (non-declarative memory). The consciousness memory system develops later meaning the appearance of functional declarative memory in the long term is associated with the development of language, theory of mind, and generally the acquisition of a sense of self. There is evidence, however, that by 14 to 18 months infants are capable of some form of declarative memory (Meltzoff, 1995). Finally, the distinction between storage and retrieval failure remains unresolved, but debates in favor of one or the other have perhaps been superseded by the paradigm of multiple memory systems. What is lacking is a a better understanding of the role of emotional development in the development of memory and forgetting, and the role of the amygdala in this process, a structure deeply involved in emotional learning.
See Affordance, Amygdala, Autobiographical memory, Childhood amnesia, Declarative (or explicit) memory and procedural memory, Emotional development, Hippocampus, Inferior temporal cortex, Memory, Neocortex, Neurogenesis, Prefrontal cortex (PFC)