For example, participants were shown a tiger at a playground and then asked to determine whether they had previously seen the animal (the tiger), the location (the playground), or the animal in the location (the tiger at the playground). In one study, 4-year-olds, 6-year-olds, and adults were tested on their ability to recall isolated parts of pictures as well as combinations of these parts ( Sluzenski, Newcombe, & Kovacs, 2006).

These studies suggest that the ability to remember details of events improves dramatically across early childhood and becomes robust around the sixth year. Lab-based studies identify a developmental timeline of memory that is similar to that identified by naturalistic studies. Thus, although autobiographical and lab-based memories differ, they share critical overlapping core features since both require memories for the details of previous experiences. The advantage of this approach is that lab-based events can be designed to be manipulated experimentally. Similar to real-world events, in these laboratory paradigms, children are presented with events that are rich in contextual details (i.e., specific items encountered at particular times and places) and then asked to recall these details after a delay. As a result, some researchers have turned to controlled, laboratory-based episodic memory paradigms. Because of this variability, it is often challenging to manipulate these events parametrically to probe mechanisms underlying changes in children’s ability to recall them. However, the events and details recalled vary considerably among children. Studies examining children’s memories for real-life events have high ecological validity. Thus, although childhood amnesia may extend through childhood, after about the sixth year, the stability and consistency of memories increase dramatically (e.g., Bauer & Larkina 2014, 2016 Peterson et al., 2011). Moreover, among children, 4- to 6-year-olds forget more rapidly than 8-year-olds, particularly during open-ended recall of autobiographical memories. When rates of forgetting are assessed empirically, 4- to 8-year-olds forget more rapidly than adults ( Bauer & Larkina, 2016). For example, when researchers track young children’s memories over time, results suggest they grow into their amnesia this means that although 3- and 4-year-olds initially recall details of events, these details are later forgotten. Building on this landmark study, a sizable empirical literature now documents accelerated rates of forgetting for autobiographical memories across childhood (e.g., Bauer & Larkina, 2014, 2016 Peterson, Warren, & Short, 2011). In one of the earliest studies on autobiographical memories, although children as young as 3 years could recall a family vacation to Disneyworld after six to 12 months, the older the children were during the trip, the more details they remembered ( Hamond & Fivush, 1991). However, the same research suggests that early memories are extremely fragile and prone to being forgotten, especially when they include the details of events (e.g., Bauer, 2015 Bauer & Larkina, 2014, 2016). In fact, even very young children can form memories for events (see Bauer, 2006, for a review). Although it was originally thought that early experiences were simply not encoded into memory ( Piaget & Inhelder, 1969), research with young children has repeatedly documented that this is not the case. Why is it then that, as adults, we recall so little from our childhood? This inability to remember, termed infantile amnesia or childhood amnesia, is one of the most robust and replicable phenomena in developmental psychology ( Freud, 1910 Newcombe, Lloyd, & Ratliff, 2007 Pillemer & White, 1989). The ability to remember details from events in life is critical for functioning and a personal sense of self. How Does the Ability to Remember Change Across Development? Taken together, these results suggest that protracted neural development of the hippocampus, cortex, and connections between these regions contribute to the fragility of memories early in life and may ultimately contribute to childhood amnesia. Data from young children have also shown that activation of cortical regions during memory tasks and the functional connectivity between the hippocampus and cortex relate to memory during this period. Yet the hippocampus is only one region within a larger network supporting memory. Recent empirical studies in early childhood reveal that the development of specific subdivisions of the hippocampus (i.e., the dentate gyrus) are related directly to variations in memory. Although numerous factors contribute to this phenomenon, data show one major source of change is the protracted development of neural structures related to memory. Memories for events that happen early in life are fragile-they are forgotten more quickly than expected based on typical adult rates of forgetting.

Early childhood amnesia