Childhood amnesia

Childhood amnesia, also called infantile amnesia, is the inability of adults to retrieve episodic memories (memories of situations or events) before the age of two to four years, as well as the period before the age of ten of which adults retain fewer memories than might otherwise be expected given the passage of time. The development of a cognitive self is also thought by some to have an effect on encoding and storing early memories. Childhood amnesia, also called infantile amnesia, is the inability of adults to retrieve episodic memories (memories of situations or events) before the age of two to four years, as well as the period before the age of ten of which adults retain fewer memories than might otherwise be expected given the passage of time. The development of a cognitive self is also thought by some to have an effect on encoding and storing early memories. Some research has demonstrated that children can remember events from the age of one, but that these memories may decline as children get older. Most psychologists differ in defining the offset of childhood amnesia. Some define it as the age from which a first memory can be retrieved. This is usually at the age of three or four, but it can range from two to eight years. Changes in encoding, storage and retrieval of memories during early childhood are all important when considering childhood amnesia. Childhood amnesia was first formally reported by psychologist Caroline Miles in her article 'A study of individual psychology', in 1893 by the American Journal of Psychology. Five years later, Henri and Henri published a survey showing that most respondents' earliest recollections occurred from the age of two to four. In 1904 G. Stanley Hall noted the phenomenon in his book, Adolescence: Its Psychology and Its Relations to Physiology, Anthropology, Sociology, Sex, Crime, Religion and Education. In 1910, Sigmund Freud offered one of the most famous and controversial descriptions and explanations of childhood amnesia. Using psychoanalytic theory, he postulated that early life events were repressed due to their inappropriately sexual nature. He asserted that childhood or infantile amnesia was a precursor to the ‘hysterical amnesia,’ or repression, presented by his adult patients. Freud asked his patients to recall their earliest memories and found that they had difficulty remembering events from before the age of six to eight. Freud coined the term 'infantile' or 'childhood amnesia' and discussed this phenomenon in his Three Essays on the Theory of Sexuality. In 1972, Campbell and Spear published a seminal review about childhood amnesia in Psychological Sciences recapping the research conducted to understand this topic from neurological and behavioral perspectives in both human and animal models. The method of memory retrieval can influence what can be recalled. Specifically, whether an individual is prompted to remember a specific event, given more general guidelines, or asked to recall any memory possible, the cue method generates different results. Many studies use cued recall to retrieve memories. In its basic form, the experimenter gives the participant a word, and the participant responds with the first memory they think of associated with that word. This method has generally estimated the age of offset at about three to five but can vary. However, there are several objections to the cue method. One memory is recorded per cue word, so it can be difficult to know whether this memory is their earliest memory or the first memory that popped to mind. It may be a problem if participants are not asked to record the earliest memory they can recall which relates to the cue. If the experimenter asks the participant to specifically use childhood memories or the earliest memories associated with a cue, the age estimate can be two to eight years. Even with this measure, cued recall is only useful for bringing to mind memories formed several months after the introduction of that word into the participant's vocabulary. One study performed by Bauer and Larkina (2013) used cued recall by asking children and adults to state a personal memory related to the word and then state the earliest time that it occurred. The researchers found that the younger children need more prompts or cues. However, for both children and adults, the earliest memory retrieval was around three years old. Free recall refers to the specific paradigm in the psychological study of memory where participants study a list of items on a specific trial, and are then prompted to recall the items in any order. Free recall, in regard to childhood amnesia, is the process by which experimenters ask individuals for their earliest memories, and allow the participant to respond freely. There is no significant difference when people are instructed to recall their earliest memories with cued recall compared to free recall; however, it is thought that a major benefit of free recall is that every question gets answered which may in turn elicit memories from an earlier age. In the exhaustive recall method, participants are asked to record all the memories they can access before a specific age. This method, like free recall, relies on participants to come up with memories without cues. Exhaustive recall yields a better understanding than others on the amount of memories surviving from early childhood, but can be demanding for the subjects who often have to spend many hours trying to remember events from their childhood. No major differences among word cued, interview, focused and exhaustive recall have been found. The amount of early childhood memories a person can recall depends on many factors, including emotion associated with the event, their age at the time of the remembered event and the age at the time they are asked to recall an early memory. Although people assume that not recalling a childhood memory means they have forgotten the event, there is a difference between availability and accessibility. Availability of a memory is the idea that the memory is intact and is in memory storage. Accessibility of a memory is dictated by the moment in time that a person attempts to recall that memory. Therefore, cues may influence which memories are accessible at any given time even though there may be many more available memories that are not accessed. Some other research suggests that people's earliest memories date back to the ages of 3 or 4 years. J. A. Usher and U. Neisser (1993, this issue) reported that some events, like the birth of a sibling and a planned hospitalization, can be readily remembered if they occurred at age 2. However, the bits and pieces of such memories that were obtained in their research may not be indicative of genuine episodic memory. An alternative hypothesis is that these apparent memories are the result of educated guesses, general knowledge of what must have been, or external information acquired after the age of 2.