Infant memory breakthrough: Early memories just hard to retrieve
Why don't we remember our early years? For a long time, it was believed that infants lacked the ability to remember. However, recent research shows that this assumption was incorrect. Children as young as 12 months old are already capable of encoding memories.
For many years, it was thought that first memories form around the age of 3. New research using fMRI (functional magnetic resonance imaging) challenges this belief. The latest findings undermine earlier theories that suggested memory formation during infancy is impossible.
Researchers have concluded that memories are indeed recorded in the minds of 12-month-old children. The difficulty in recalling early years may stem more from troubles in retrieving memories than from their absence.
Memory encoding in infants
The inability to recall memories from early childhood is known as childhood amnesia. One theory suggested that the cause is the underdevelopment of the hippocampus, a key brain area responsible for short-term memory. According to Scitech Daily, studies on rodents have shown that memory traces are created in the hippocampus of infants but become inaccessible over time.
In a study led by Tristan Yates and his team, fMRI was used to scan the brains of infants aged 4 to 25 months as they performed a memory task. The task involved showing the infants images of faces, scenes, and objects, followed by testing their memory through preferential looking.
Surprising study results: Why don't we remember early childhood?
The results showed that by around the 12th month of life, an infant's hippocampus is capable of encoding individual memories. This strongly suggests that the ability to form memories begins in infancy. The presence of memory encoding mechanisms, despite their temporary nature, supports the theory that childhood amnesia is mainly due to difficulties in retrieving memories.
These findings are consistent with earlier rodent studies, suggesting that early life memories may persist into adulthood but remain inaccessible without specific cues or direct stimulation of hippocampal engrams. In a commentary on the study, Adam Ramsaran and Paul Frankland analyze how these early memories are stored and lost.
The study, published in "Science," offers new insights into how our brains develop. Observations align with previous rodent studies, indicating that memories from early life stages may persist into adulthood but remain inaccessible without specific cues or direct stimulation of hippocampal engrams.
