Researchers have found that when our brain tries to remember a past event, it reconstructs that experience in reverse order, according to a study released on Monday by the University of Birmingham.
The study was conducted by researchers from the university's Centre for Human Brain Health. They reconstructed the memory retrieval process, using brain decoding techniques. These techniques make it possible to track when in time a unique memory is being reactivated in the brain.
"Memory is a reconstructive process, biased by personal knowledge and world views -- sometimes we even remember events that never actually happened. But exactly how memories are reconstructed in the brain, step by step, is currently not well understood," said Juan Linde Domingo, lead author of the study.
The team found that, when retrieving information about a visual object, the brain focuses first on the core meaning and only afterwards recalls more specific details.
This is in sharp contrast to how the brain processes images when it first encounters them. When we initially see a complex object, it's the visual details -- patterns and colours -- that we perceive first.
Abstract, meaningful information that tells us the nature of the object we're looking at, whether it's a dog, a guitar, or a cup, for example, comes later, according to the report.
The study has been published in the journal Nature Communications.
Next, the team will need to test whether this reversed reconstruction cascade is "hard-wired" in the brain. They are also looking in more detail at how and where the brain reconstructs more complex memories, reports Xinhua.
Once the pathway of memory retrieval is established in the healthy brain, researchers can also start looking into how it is altered in healthy ageing, or how this pathway might contribute to the over-generalisation of memories in conditions like post-traumatic stress disorder, said the researchers.