12.4.1: Memory

Learning Objectives

1. Describe the three stages of memory.
2. Differentiate between implicit and explicit memory, including the typical contexts in which each typically emerges.
3. Define and explain infantile amnesia.
4. Identify strategies caregivers and professionals can use to support memory development in infancy and toddlerhood.

Memory is a fundamental cognitive process that allows us to store, retrieve, and use information. In infancy and toddlerhood, memory development lays the foundation for learning across all domains. While long-term memory allows for lasting retention, infants must first develop the ability to encode and consolidate information. Understanding how memory functions at this stage can help us explore why infants remember some experiences while forgetting others, as well as the factors that support early memory development.

Stages of Memory

Memory progresses through different stages: sensory memory, short-term memory, and long-term memory. Sensory memory is the first stage and involves the brief capture of sensory information (such as sights, sounds, and textures). In infants, sensory memory is already functional at birth, allowing them to begin recognizing patterns, such as their mother's voice or the shape of a caregiver's face. However, sensory memories last only a fraction of a second unless attended to.

Short-term memory (also called working memory) is where information is temporarily held for processing. Infants have a very limited capacity for short-term memory. Research by Renée Baillargeon and others suggests that by around six months, babies can hold information in their working memory for brief periods, such as remembering the location of a hidden object. However, they need repetition and engagement to transfer this knowledge into long-term storage.

Long-term memory is the final stage, where information is stored in a more permanent manner. Unlike sensory and short-term memory, long-term memory has a much larger capacity and can last for extended periods, potentially a lifetime. However, memory development in infancy differs significantly from that of older children and adults.

Figure \(\PageIndex{1}\): Diagram of the memory storage process. Image by Wikipedia is licensed under CC BY-SA 3.0.

Types of Long-Term Memory

Long-term memory, which has an immense capacity and can store information indefinitely, is often categorized into explicit and implicit memory. These two types of memory develop at different rates during infancy and toddlerhood.

Implicit Memory

Implicit Memory (also called procedural memory) develops first. This type of memory enables infants to recall how to perform tasks, such as sucking, grasping, and eventually crawling and walking. These skills do not require conscious recall; instead, they are built through repeated experience and become automatic. Even very young infants can retain implicit memories—for example, research has shown that two-month-old babies can remember how to kick their legs to move a mobile for up to a week after the experience (Rovee-Collier, 1999).

Explicit Memory

Explicit Memory, also known as declarative memory, takes longer to develop because it requires conscious thought. There are two types of explicit memory:

1. Semantic memory (knowledge of facts, such as recognizing objects or learning words) and
2. Episodic memory (memory of personal experiences).

Babies begin forming basic episodic memories by their first year, but these memories are fragile and can be easily forgotten. By the toddler years, explicit memory improves as children gain language skills and begin to recall past events.

While newborns can form implicit memories, explicit memory does not become well-developed until later in infancy, with significant improvement occurring around the second year of life (Rovee-Collier, 1999).

Infantile Amnesia

Despite infants’ ability to form memories, most people cannot recall personal events from early childhood, a phenomenon known as infantile amnesia (Bauer, 2007). This occurs because the brain structures responsible for explicit memory, particularly the hippocampus and prefrontal cortex, are still developing during infancy. Without a fully mature memory system, young children struggle to encode and retrieve detailed autobiographical memories. However, research shows that while explicit memories may not last, implicit learning from infancy continues to influence later behavior.

Figure \(\PageIndex{2}\): A toddler walking. Image on Public Domain Pictures.

Supporting Memory Development with Infants and Toddlers

Although infantile amnesia prevents most early memories from lasting into adulthood, early experiences still significantly shape brain development and learning. Caregivers, educators, and other early childhood professionals can support memory development in young children by offering

• repetition and routine throughout the day (through words, songs, and actions),
• interactive play and exploration through hands on activities and responsive interactions,
• language and storytelling (specifically about past events in order to connect experiences with language), and
• emotionally meaningful experiences, as strong emotions enhance memory retention. Events that are exciting or meaningful, such as a trip to the zoo, are more likely to be remembered.

References, Contributors and Attributions

Bauer, P. J. (2007). Remembering the times of our lives: Memory in infancy and beyond. Psychology Press.

Gómez, R. L., Bootzin, R. R., & Nadel, L. (2006). Naps promote abstraction in language-learning infants. Psychological Science, 17(8), 670-674.

Rovee-Collier, C. (1999). The development of infant memory. Current Directions in Psychological Science, 8(3), 80-85.

Ross-Sheehy, S., Oakes, L. M., & Luck, S. J. (2003). The development of visual short-term memory capacity in infants. Child Development, 74(6), 1807-1822.