Remember When?: Infantile Amnesia

Introduction

Memory. It is the internal scrapbook that defines one’s individuality—a sense of self that is crucial to the human psyche. Nevertheless, due in large part to its longevity, memory is a difficult term to define. It appears to be ineffaceable, a solid entity of the past, yet it frequently eludes its owner, making one question the validity and transiency of memory. These large memory gaps of narratives are difficult to seal, thereby creating a disconnect between one stage of life and another. One of the most common and largest gap in the human memory bank consists of recollections of the first few years of infancy and babyhood. Ever wonder why it is a struggle to remember an event prior to the age of two? Or even the day you were born? One wonders why such a significant event as one’s birth fades into oblivion, never to be recovered. This inevitable condition is identified as infantile amnesia, a term forged by the renowned Sigmund Freud when he commenced his studies of this marvel in 1905 (1). Significant light has been shed on the details concerning the nature of infantile amnesia since Freud’s era, yet many mysteries remain. For example, how does autobiographical memory shape infantile amnesia? Autobiographical memory or personal memory is a branch of memory that is established for encoding, storing, and retrieving events and experiences to construct one’s personal past. Psychologists have demonstrated that autobiographical memory minimizes the constraints of this particular amnesia, but one question remains unclear—what inhibits autobiographical memory? It is a question that has beguiled psychologists for nearly half a century. This paper will investigate the different and oftentimes opposing theories that help explain the elusive phenomenon of infantile amnesia.

Mapping Memory—A Brief Overview

Memory is a complex entity of the human brain. Declarative and non-declarative memories are central, but distinct divisions exist that contribute to our notion of forming memories. Declarative memory is devoted to processing names, places, events, and facts. Semantic and episodic memories are the two subtypes of declarative memory. Semantic memory supports retention of “knowledge of facts and data that may not be related to any event” (2), while episodic memory relates more heavily to unique events linked to place and time. Perceptual and motor skills contribute to non-declarative memory, which does not necessitate the deliberate recall that declarative memory requires. Furthermore, autobiographical memory is a component of declarative memory that is particularly episodic because it is linked spatially and temporally to unique events.

Memory—A Fallacy?

In any study, there is the likelihood of experimental error. In fact, errors are expected because 100% accuracy is virtually impossible. But in the case studies concerning infantile amnesia, are the methods faulty or are the components of the human subconscious at fault? Could both play an integral role in the results? Stuart Zola explores the reliability of memory in his 1998 case studies on infantile amnesia. People who have recovered memories help researchers understand the biological and behavioral factors of memory. Zola’s objective was to answer two questions about memory: 1) do memories for traumatic events change over a period of time; and 2) can memories be created for traumatic events that didn’t occur? Infantile amnesia is the inability to recollect memory at certain stages of infancy. An explanation that Zola gives for infantile amnesia points to the slow maturation of the cortical areas after birth. Processing and storing information necessary for reconstruction of conscious memories occurs later. According to Zola, infantile amnesia provides a restrictive component on recovered memory. Yet, there are some cases in which recovered memories from early infancy were described in great detail (3).

Recently, researchers attempted to “create” memories for the subjects by collaborating with their families who were instructed to “remind” the participant of an early event that had never actually occurred. The participants were, of course, unaware of their family’s involvement in the experiment. They were asked several questions, and their answers were tape-recorded and replayed to their respective families for further analysis of accuracy and specificity. Results showed that 25% of the subjects “recalled” the false events and even furnished additional, fabricated details when asked by researchers to retell the event. This experimental data affirms forgery of false infantile memories (3).

Zola’s other studies have shown that there are other memory systems in the brain that may affect memory recall. The overall conclusion drawn from Zola’s report speaks to the pliable nature of memory. Memory is the materialization of ideas distributed across the brain, not localized in one region. Zola claims that memory corresponds with regions of the brain that help dictate the real from the imagined, and these regions establish the temporal position of the memory. In his report, Zola makes note of the biological basis of memory and its distortions.

Zola provides anecdotal evidence as well as experimental evidence for his hypotheses, all of which seem to support his conclusion. His report informs future studies that it is important to take several types of memory into consideration, because relying on just one would give misleading results due to the fact that memory is controlled by multiple brain systems. And because it is difficult to understand clearly the causes of infantile amnesia, researchers should not assume that the recollections provided by participants in their research are complete and valid (3).

Revelations about Autobiographical Memory and its Relation to Language

One of the most definitive factors of autobiographical memory is that it has the potential to be verbalized. If a memory can be expressed verbally and understood, others are given the opportunity to internalize that memory in a way that will help them associate it with the individuality of others. But to what extent are the implications of verbalization a factor of autobiographical memory? In their 1999 case experiment, Keryn Harley and Elaine Reese focused on the cognitive and social factors of autobiographical memory in 1.5 to 2.5 year-old children. According to Harley and Reese, autobiographical memory functions to facilitate individuals’ learning about others by relating past experiences. Harley and Reese reviewed the experiments of self knowledge theorists who argued that the lack of understanding of personal self contributed to infantile amnesia. With the acknowledgement of the cognitive self, greater stores of autobiographical memory are produced. As awareness of self becomes stronger, there is more interplay among the different types of memory, which allows us to develop individuality (4).

Harley and Reese drew on earlier studies that demonstrated that parents who are able to elaborate information about past events expand on their childrens’ memory information. Parents’ “talk” assists in children’s “memory talk,” because it helps develop childrens’ ability to describe autobiographical memories (4). In a 1993 study, Harley and Reese used several methods in a novel experiment that showed the interplay of Howard and Courage’s self-knowledge and parental styles of communication (4).

In order to assess childrens’ verbal memory and maternal styles of reminiscing, mothers were asked to choose several one-time events that they shared with their children (i.e. feeding ducks at the local pond, airplane flights). The events were then introduced into a conversation between mother and child. Conversations were videotaped and audio-taped by researchers in order to maintain a profile for each mother-child case. During designated monthly time intervals, children would be prompted to discuss past events with their mother. The purpose of the experiment was to determine how well the child’s elaboration of events depended on the mother’s maternal reminiscing style. They hypothesized that the extensiveness of the mother’s language style would result in stronger memory elaborations of the child. Mothers facilitated recalls by giving three event-specific cues to prompt more detailed responses. Event cues were observed to be effective if they overlapped with information already stored in the memory. The mothers were strongly discouraged to provide further assistance beyond just the cues (4).

According to Harley and Reese, the role of the parent in interacting with the child is not only crucial to the child’s communication skills, but also significantly impacts the child’s autobiographical memory. Parents who provide greater detail when speaking about the past with their children and who follow their child’s conversation cues, tend to engage their child in discussions more than parents who do not provide elaborative conversations. The parents that do not engage in discussions inhibit narrative construction of their children. Children with parents who are more expressive and vocal develop the ability to recall and vocalize past events more lucidly, especially during the window of infantile amnesia. Thus, maternal stylized elaborations encourage children to synthesize narratives heavy in diversified content and breadth as early as age three. This has lasting impressions on children because it increases and reinforces the amount that older children recall from earlier recollections. Children who were capable of vocalizing thought at the time of an experience connect memory and language more naturally, because events can be encoded verbally (4).

Speculations about Early and Late Memories

Harley & Reese’s experiments are strongly suggestive of how excellent verbalization of recollections aid in the continuity of autobiographical memory. But one can’t help but question whether there are disparities between memories of early life and those of later years. In 1999, Tiffany West and Patricia J. Bauer pioneered a study in which they attempted to characterize the differences between early and late memories. It is known that memory recall for most adults during the first years of life is limited. The few that have remained for recall have strong emotional impact on the individual. These memories, interestingly, are recalled in the third-person, rather than the first-person, perspective. This is most likely due to the fact that recognition of self has not fully developed. As later memories form, the perspective sharply changes to the first person West and Bauer, in their research, studied the differences in memory storage in two stages in human development—from as early as age 5 to as old as age 10 (1).

Using the same methods in male and female test subjects, experimental evidence showed that there are few differences between early and later memories in both sexes when three variables—emotion, perceptual information, and perspective—are accounted for. In two sessions, West and Bauer asked male and female students of University of Minnesota to report events that they recalled from their childhood. In the first session, students had to report four memories from before the age of seven. In the second session, students were asked to report on memories after the age of seven. Both sessions were conducted in one sitting and everyone had one week to complete the reports. It was important for accuracy and details to be accounted for equally. (1).

Delineating Infantile Amnesia

Memory can be difficult to interpret if the context in which it is described is not understood entirely by another party. In a 2005 study, Darryl Bruce examined the depth of memory expression in young adults, by focusing in on the nuances between first memory fragments and first event memories. Bruce defines memory fragments as isolated memory moments that have no event context and are remembered as images, behaviors, and emotions. First-fragment memories are believed to form earlier in life than first event memories. Bruce and his team concluded that the childhood amnesia is gradually supplanted by fragments of early childhood experiences, and not by episodic memories.

In Bruce’s experiment, the research team designed a web survey taken by 185 students from Saint Mary’s University. Students were asked to provide information about their lives, in addition to their earliest memories. The students indicated the age at the time the memory had taken place and the corresponding confidence in this approximation. The participants believed that they were younger when they had their earliest fragmental memory. These results are reflected in the calculated mean ages of the participants who had been divided according to the information they were asked to provide. Data showed consistency regarding the expected early timeframe of fragmental memory of the participants. Results not only showed significant uncertainty in the times when the fragmental memory was estimated to have occurred, but also poorer content quality (5).

Autobiographical Memories Across a Wide-Age Range

Studies of infantile amnesia frequently examine adult subjects, but few have used adolescent. In a 2005 study conducted by Peterson, Grant, and Boland, memory recollection was investigated in 136 young children and adolescents in the 6-19 age range. Involvement of parents was crucial, because they provided the facts that would help the researchers attain more accurate results (6).

Over several years, researchers visited the homes of the recruited participants to conduct the investigations. Each participant had to answer several questions regarding the earliest recollections of their childhood. A parent or guardian provided confirmation of details as needed. If parents believed certain memories were incorrect, that information was discarded. Also, if parents believed that certain recollections were based explicitly on photos and videos, those memories were excluded. The research team then developed a scoring system that took into account age of earliest recollections, nature of the event, emotional tone, structure, and social orientation surrounding the memories.

Children who were between 6 and 9 had earlier memories than older children. In contrast, older children tended to have more emotional memories than younger children, and there were few gender differences across all the children’s ages (6).

Culture and Infantile Amnesia

Zola, Bruce, Harley, Reese, and Bauer studied different factors that affect infantile amnesia, yet none took into account cultural implications on memory. In 2003, Qi Wang provided evidence that childhood environment can significantly affect autobiographical memory and infantile amnesia. Just as there are different maternal styles of elaborations that affect memory, broader factors such as cultural difference also affect the degree of memory recall. In his recent cross-cultural study, Wang recognized the differences in memory between Eastern and Western culture groups. Wang and his team compiled memory narratives from American and Chinese mothers and their three to four year old children. They had asked 154 Chinese and American children a series of questions relating to early memories, which they took note of and documented in tape-recordings. On average, Caucasians in Western nations have a relatively good recollection of events by 3.5 years in age. Asians attained similar levels of recollection as Caucasians, but generally after several months after 3.5 years (7).

Not only does the average temporality of earliest memory vary between cultures, but the nature of event recall also seems to be quite different. Wang’s testing of international subjects demonstrated that Western childhood memories tended to be self-focused and emotionally detailed, while Chinese childhood memories were more generic and not heavily focused on the individual. The results stem from different child-rearing practices and beliefs: Western nations tend to place more emphasis on socializing children than Eastern nations. This explains why American children provided more emotionally detailed memories than their Chinese counterparts. Traditionally, Chinese families do not introduce social skills until the child reaches 6 years of age. By that age, children are disciplined in societal and filial duties (7).

Where the Problems Lie—The Issue of Infantile Amnesia

Factors that are important in autobiographical memory formation are multitudinous and complex. Although the multiple studies have different experimental focuses, they collectively show that autobiographical memory is dynamic and is closely related to infantile amnesia.

Before one can draw conclusions about infantile amnesia, one must first question the validity of autobiographical memory, and thus, the results of the experiments above. Stuart Zola’s study is most relevant in resolving the issue, because he addresses the fallacies of memory. We are all susceptible to different kinds of memory distortions. At times, distinguishing between the real and the imagined leads to confusion. Such confusion is the result of the dynamism of memory. And so, memory cannot be categorized as a simple, well-understood entity. Storage of autobiographical memory, for example, is affected by new events. Consequently, certain components of a memory may differ from its original versions, facilitating the loss of some information. Therefore, memory recalls will not only be distorted, but also incomplete, due to consistent synaptic changes that occur with every memory recall of a person (3).
Our bodies are changing constantly—from the ions that exit certain protein channels to the reproduction of cells that make up our skin tissue by the process of mitosis. So it should come as no surprise that our neural connections are just as dynamic as other regions in the body. If these synapses are constantly changing, then wouldn’t the stored information that is being transmitted change as well? It is important to recognize that the reorganization of neural configurations change gradually with time (3). However, memory doesn’t change quickly within one period in development. If this were the case, complications in learning would arise and information would be highly unreliable. But since humans are always learning, even during infancy, information changes do not occur too quickly in just one stage of development.

Thus, when juxtaposing Zola’s analysis with Bauer and West’s results, one observes sharp contrasts. Bauer and West’s results showed that there are no substantial differences between early and late memories. One may be inclined to accept the validity of the data, however, it is difficult to reconcile that memories in two distinct stages (early age 5 and latest age 10) in human development are considerably consistent. Developmental differences must play a critical role in memory. Older people tend to have more understanding and awareness of the world, allowing them to evaluate cause and effect in their lives. A higher degree of understanding allows for a greater level of recollection. Furthermore, older children and adults have the unique ability to rationalize events well. Interpretation of the results in the experiment may have been right, but the results themselves could have been flawed, due to the subjectivity of the participants, who may have unintentionally favored one version of an event over another. West and Bauer considered such possibilities themselves in their final discussion to show that they are aware of potential sources of error. If all potential errors are set aside and the results are legitimate, then West and Bauer’s discovery of similarities between stages of memory and its implications on autobiographical memory is telling (1).

Furthermore, there is a discrepancy between Peterson’s, Grant’s, and Boland’s 2005 results and West’s and Bauer’s 1999 results, even though both had studied similar subjects and their early and later memories. In the 2005 study, the researchers found that older children’s memories are likely to follow an articulate narrative form, unlike younger children’s memories, which likely account for specific moments in time. They then concluded that earliest memories of younger children reflect less elaborative narrative skill, which is quite similar to Harley and Reese’s findings in their 1999 study. Basically, their results suggested that differences do exist between early and later memories (6).

In many of the studies described above, researchers and participants alike had been reared according to Western ideologies and practices. But what implications do their results suggest on a global scale? Like suggested earlier about Qi Wang’s report, there may be slight flaws in the contemporary theories regarding infantile amnesia because they are rooted primarily in Western views, which do not correlate exactly with other cultures. Qi Wang clearly details the facts about how infantile amnesia is not a standard condition because nurture — religion, behavioral lessons and expectations, philosophy and politics—plays a role. Autobiographical memory is not only an expression of the individual, but it is also a product of culture. Results on infantile amnesia should be considered carefully and with great caution, especially when other cultural standards may play a role (7).

Conclusion

Though we now know more about infantile amnesia than ever before, the data is still inconclusive. This is because memory is not simply an object one can place in a pitri dish to observe via a microscope. It has too many possible distortions and too many unaccountable gaps to draw incontestable conclusions. Yet still, we cannot allow the unreliability of memory to deter further study and consideration of experimental data such as that of West and Bauer’s 1999 experiment. These studies help us achieve a greater understanding of the elusiveness of memory. We could also learn more about ourselves, since infantile amnesia is tied so closely to autobiographical memory.

We understand some of the neurological, cognitive, social, and cultural factors that explain why almost every human being has so few recollections of the first years of their lives, but we need to explore the issue further. Our scrapbooks still contain missing pages, but with more carefully conducted experiments, we will be able to reconstruct our pasts and live for a more enlightened future.

References
1. T. A. West, P. J. Bauer, Memory. 7, 3 (1999).
2. J. E. Zull, The Art of Changing the Brain: Enriching the Practice of Teaching by Exploring the Biology of Learning, Stylus Publishing, Sterling, 2002, p. 81.
3. S. Zola, Clinical Psychology Review.18, 8 (1998).
4. K. Harley, E. Reese, Developmental Psychology. 35, 5 (1999).
5. D. Bruce, Memory & Cognition. 33, 4 (2005).
6. C. Peterson, V.V. Grant, L. D. Boland, Memory, 13, 6 (2005).
7. Q. Wang, Memory. 11, 1 (2003).