Childhood Amnesia

Childhood or infantile amnesia is the inability of adults to recall autobiographical memories from early childhood (Eyesnck & Keane, 2013). We are generally unable to remember memories from before the first three to four years of our life. By the time children are two years old, they are able to answer questions about recent events although they often need careful prompting to retrieve the memories. Over the next four or five years, children become better at recalling and describing important events in their lives and by the age of seven or eight, most children have well-developed autobiographical memories with the same rate of normal forgetting seen in adults. An extensively used method for testing childhood amnesia is the cue word technique.

It has been theorized that this continuous integration of neurons, also known as neurogenesis might also rearrange connections in the brain and thus destabilizes some memories that were already there, causing one to forget them. Katherine Akers et al. (2014) carried out a study to show that this does happen in mice, guinea pigs and small rodents, degus. They administered mild electric shocks to train mice to fear particular environments. Some of the mice were then given access to running wheels as running has shown to increase the generation of new neurons. Later when the mice were returned to the environment they were trained to fear, they found that the mice with running wheels had largely forgotten their fears, while the mice without running wheels seemed to remember the electric shocks very well. This occurrence appeared to be similar to infantile amnesia. Akers et al. (2014) then used drugs to slow the rate of neurogenesis in infant mice and found that those infant mice were better able to retain memories. Aker’s et al. (2014) then tested the effects of neurogenesis on guinea pigs and degus and discovered that these species did not forget their fears as quickly as mice when they were infants. However, when they gave the infant

They followed up with the participant’s years later to see how much they remembered and at the ages of five, six and seven, the children could recall more than 60% of the earlier events, but by the ages of eight and nine their recall was less than 40% (NPR.org, 2014).

In spite of the evidence in support of the neurogenesis theory there is still research demonstrating that infants can form long term memories. Fivush, Gray and Fromhoff ((1987) as cited in Eyesneck & Keane (2015)) conducted a study with young children with the mean age of 33 months. They were asked questions about significant events they had experienced in the months previous to the experiment. The children responded to over 50% of the events and produced on average 12 items of information about each event.

Another theory proposed to explain childhood amnesia suggests that the ability for infants to form memories coincides with certain cognitive capabilities, for example the development of sense of self and language. Lewis and Brooks-Gunn (1979) carried out a study in which infants who had a red spot applied to their nose were held up to a mirror. Those recognising their own reflection and so reaching for their own nose were claimed to show at least some sense of awareness. Practically no infants in their first year showed clear evidence of self-awareness, but 70% of infants between 21-24 months did