Neuroscientists like to use the term 'mental time travel' when talking about recollection of memories which are vivid and detail oriented about the time and place of original experience.
By analysing the brain activity of individuals performing simple memory recollection tasks, a team of neuroscientists from the Vanderbilt University have been able to gain new insights into how our brain processes these elaborate memories. The researchers found a substantial improvement in the ability to predict the order in which the participants recalled information which they had recently studied by studying the activity patterns in a specific region of the brain.
Medial Temporal Lobe (MTL) is a part of the brain which plays a central role in memory processing. However, clear insights into how this region actually controls the fidelity of an individual memory is still not known. It is obvious that not all memories are recalled equally. At one end of the extreme are high fidelity memories or moments of 'mental time travel' and at the other extreme are memories which are recollected in isolation i.e. without a lot of accompanying details.
To study how the medial temporal lobe controls memory processing, the scientists have developed a model of its internal structures. They have found that the anterior of MTL does give a signal that memory is being retrieved but doesn't indicate how detailed it is. However, when the posterior part of the MTL is active, this means that a person is recollecting a 'mental time travel' kind of memory.
This model was tested on 20 participants between 18 and 35 years of age. The individuals were given a list of 24 items and asked to decide if they were big or small, animate or inanimate and so on. After a short period of time, they were asked to recall what they had just studied.
Interestingly, when a participant's brain activity indicated that they were experiencing the "time travel" type of recollection, their response was likely to be the next item on the list (on a serial basis). However, when the brain scan indicated that the object was an isolated recollection, then the next object the person recalled could come from anywhere on the list.
According to Sean Polyn, Assistant Professor of Psychology, Vanderbilt University, these kinds of studies are very important to develop treatments for patients suffering from diseases like Alzheimer's and epilepsy which have devastating effects on one's memory.
"This demonstrates that the brain stamps memories with a temporal code. These time-travel recollections allow the brain to retrieve that temporal code, which makes memories for nearby things more accessible, in this case the next item in the list," Polyn said.
Information regarding smell, touch, sight, sound, emotions and so forth present at the time of the experience gets linked with a strong memory when it is formed. This can allow a person to bring back all those information associated with that memory in such detail that it seems like a 'mental time travel'.
REFERENCES AND FURTHER READINGS
https://news.vanderbilt.edu/2015/02/new-insight-on-how-brain-performs/?utm_source=vuhomepage&utm_medium=newsbox&utm_campaign=mental-timetravel
https://www.jneurosci.org/content/35/7/2914.short