We recall memories in a backwards process

Human memory is a complex system that scientists are still trying to figure out. How we memorize things? How later we recall these memories? Now researchers from the University of Birmingham are saying that the human brain reconstructs experiences in reverse order to allow us remember past events. Scientists say that these findings could allow making more accurate assessments of the reliability of eye witness accounts.

Scientists used brain decoding techniques in order to reconstruct the memory retrieval process. They found that at first we recall the core meaning (so called, the gist) of the events and later we retrieve memories of specific details.

This is quite interesting backwards process, because when we first encounter an image, we initially see a complex object with its visual details, such as patterns and colours. Only after that more abstract information comes to us. Scientists say that the process of reconstructing memories is still poorly understood, because it is shaped by personal beliefs, opinions and state of mind during the initial event.

Actually, scientists say that sometimes people have memories of events that didn’t even take place, but we still don’t know how that happens. Participants of this study were first shown images of specific objects. Then they were taught to associate each image with a unique reminder word. Afterwards participants were had to recall the image in as much details as possible after hearing the associated word. All this was done while their brain activity was monitored via 128 electrodes attached to the scalp. Scientists found that participants initially remembered the gist of the image – for example, whether they were thinking of an animal or an inanimate object. Only later more subtle details started coming to them.

Scientists say that this means that our memories prioritise conceptual information and not the details. This could be a part of the reason why some memories change over time. Linde Domingo, lead author of the study, said: “It suggests they will become more abstract and gist-like with each retrieval. Although our memories seem to appear in our ‘internal eye’ as vivid images, they are not simple snapshots from the past, but reconstructed and biased representations”.

Scientists will have to conduct new studies will need to test whether this reversed reconstruction cascade is deeply rooted in the brain. Scientists want to know exact pathways that play a role in this process. They say that eventually this could lead to new techniques how to check witness reports in various police investigations.

Source: University of Birmingham