Infantile “amnesia” refers to the apparent absence or weakness of memories formed at ages younger than 3 or 4. Some evidence indicates that these early-life memories are not actually lost or forgotten, but are rather merely mislabeled or otherwise inaccessible to adult cognition. One potential reason for this inaccessibility is that adults tend to use language in encoding and retrieving memories, and this strategy may not be sufficient for retrieving memories formed in early-life, which may have been encoded before language is firmly entrenched in the developing brain. A recent study in Child Development may challenge this hypothesis, as described below.
In “Fragile But Real: Children’s Capacity to Use Newly Acquired Words to Convey Preverbal Memories,” authors Morris & Baker-Ward brought a remote-controlled bubble machine with six colors of bubble mixture to several preschools, tested children on their knowledge of color names, and then told children that the machine would only work when a particular color was used (the experimenters pointed to, but did not name, this color of soap).
Over the course of two days, 80 two-year-olds individually interacted with the bubble machine, pouring differently colored bubble soaps into the machine. The experimenters surreptitiously activated the machine only when the correct color soap was added. The experimenters returned to each preschool once per week for the following 8 weeks to play a color naming game with each class for about 1 hour each time. Then, at the end of this 2 month delay period, children were tested on their color knowledge and then asked which color had activated the bubble machine 2 months ago. From each child, the experimenters collected a verbal response, a pointing response (in which children pointed to a color on a color chart) and a functional response (in which children were asked to add the correct color soap to the bubble machine).
The results showed that even children who did not know their color words at the time of the bubble machine experience were able to name the target color 2 months later, and they did so significantly more often than would be expected by chance alone. At least in this case, it seems that preverbal experience is accessible with words several months later, at least in the presence of adequate contextual support (the bubble machine and colored bubble soaps were visible at the time of the test). Yet three-quarters of these children were not able to successfully name the target color even though they could point to it, suggesting that for a majority of children these preverbal experiences are not recoded verbally.
The authors suggest that this work challenges interpretations of childhood and infantile amnesia pointing to failures to translate preverbal experiences into language once language is acquired. Yet the fact that three-quarters of children fail to do this, even in the presence of physical reminders of the original experience, seems to support this claim rather than undermine it. Perhaps some children can recode these preverbal memories into language when prompted, but children may still not due this under real-world circumstances and thus experience childhood “amnesia.”
What these results do clearly demonstrate is that experience can be coded in a non-linguistic form, and that recoding into language is possible, at least over short delays. The nature of these non- or sub-linguistic representations is unclear, as are the mechanisms which allow recoding of those representations into language and their sensitivity to decay. Nonetheless, Morris & Baker-Ward have provided fascinating evidence that the world of preverbal experience is not necessarily completely lost to language-capable cognition.