The hippocampus is a brain structure crucial for forming and recollecting memories of our personal experiences, which are known as episodic memories. It was thought that each memory is processed by a completely separate set of neurons within a part of the hippocampus called CA3.
However, using
functional MRI brain scanning, researchers at UCL Institute of Neurology funded
by the Wellcome Trust, have found that CA3 “memory traces” can
in fact overlap when the memories are very similar to one another, leading to
the experience of memory confusion or interference.
Intriguingly, the
researchers also found that variations in the physical size of CA3 predicted
differences in the extent of memory trace overlap and memory confusion across
the research participants.
Further information:
Chadwick, M.J., Bonnici, H.M., Maguire, E.A. CA3 size predicts the precision of memory recall. PNAS. Available online 7th July 2014. doi:10.1073/pnas.1319641111
Image: figure showing the subfields of the hippocampus, with CA3 – the topic of the paper – shown in red.