Memory has always been an interest of study for neuroscientists and psychologists. It is one topic that has been widely investigated and several studies have shown that memory is a dynamic process rather than a static one.
A group of researchers at Beijing Normal University and other institutes in China has come up with this finding. In a landmark declaration, they said that the neural representation patterns observed while the same memories are being encoded and retrieved are in some ways similar yet from the moment they are stored to when they are recalled at a later point in time, their neural representations can undergo significant transformations.
Science Advances published their findings.
The researchers used a technique called intracranial electroencephalography (EEG), which enables the collection of images of the brain with a high spatiotemporal resolution. In the study, they asked sixteen patients with epilepsy implanted with EEG electrodes in the brain for clinical purposes to complete a short-term and long-term memory task, where they were shown image and word associations and then asked to recall them after different amounts of time.
The scientists analyzed the recordings they collected while participants completed the memory tasks using deep learning techniques. This allowed them to examine the impact of neural representation transformations on the encoding and formation of memories long-term. Wing Liu and her colleagues compared the neural representations associated with specific experimental items during
Jing Liu and her colleagues compared the neural representations associated with specific experimental items during the memory encoding, short-term memory maintenance and long-term memory retrieval stages. They specifically examined the unique characteristics of these representations and how they changed over time, to try to gain a better idea of the role of memory transformations across different stages.
The researchers said that they came across substantial representational transformations during encoding. The researchers observed that the neural representations of the items that participants were asked to remember started changing right after these items were presented. In addition, they found that the neural representations of these items during the retrieval stage of the long-term memory task were more similar to those collected during the retrieval stage of the short-term memory task, than to those collected during the encoding stage.