Recovery of memory from infantile amnesia is developmentally constrained

Episodic memories formed during infancy are rapidly forgotten, a phenomenon associated with infantile amnesia, the inability of adults to recall early-life memories. In both rats and mice, infantile memories, although not expressed, are actually stored long term in a latent form. These latent memories can be reinstated later in life by certain behavioral reminders or by artificial reactivations of neuronal ensembles activated at training. Whether the recovery of infantile memories is limited by developmental age, maternal presence, or contingency of stimuli presentation remains to be determined. Here, we show that the return of inhibitory avoidance memory in rats following a behavioral reactivation consisting of an exposure to the context (conditioned stimuli [CS]) and footshock (unconditioned stimuli [US]) given in a temporally unpaired fashion, is evident immediately after US and is limited by the developmental age at which the reactivations are presented; however, it is not influenced by maternal presence or the time interval between training and reactivation. We conclude that one limiting factor for infantile memory reinstatement is developmental age, suggesting that a brain maturation process is necessary to allow the recovery of a “lost” infantile memory.

Birth Anxieties

This chapter looks at some forms and sources of birth anxiety. Our beginnings are mysterious to us, and because of infantile amnesia we can remember neither being born nor our formative years, which leaves much of our own personalities and motivations opaque to us. The chapter incorporates psychoanalytic insights into birth anxiety provided by Rank and Freud, and interprets separation anxiety as an anxiety that we suffer because of our natality. It also shows that Sartre’s and Kierkegaard’s existentialist views of anxiety leave room for certain kinds of birth anxiety. One is anxiety that we cannot honour all the obligations that come from the attachments we have inherited from birth; another is anxiety to be caught up in the wrongs of the society around us where, having been born, we are deeply shaped by these wrongs and cannot readily extricate ourselves from them.