Mental Time Travel

 timemachine

Science Daily recently posted an article covering the findings of new memory model coming out of Vanderbilt University. The study focused on the way in which the brain processes our most elaborate, detailed, and vivid memories. Dubbed ‘Mental Time Travel,’ these memories are often so detailed that we are able to recall such an extreme amount of detail, such as smells, sights, and sounds, and it feels as though we are not only remembering, but traveling back in time to when the event took place. The researchers at Vanderbilt, which houses one of the Nation’s leading memory labs, were inspired by the desire to have a better understanding of what processes our brain utilizes when searching through our memories. More specifically, they were interested in the underlying processes that determined the fidelity, or accuracy, of a given memory.

Through their research they identified two key areas of the Medial Temporal Lobe, which is known to play a substantial role in memory, that provided a glimpse into the memory processes of the brain. Their data suggests that activity in the anterior region of the MTL signals when a memory is being retrieved, but does not provide information regarding the fidelity of that memory. On the other hand, activation of the posterior region of the MTL predicted retrieval of a high fidelity, or time travel, memory. Researchers presented participants with a random word list and requested them to answer questions pertaining to the words to ensure that they paid attention to each word. These words lists were given while the participant was located in a fMRI scanner in order to collect scans of brain activity during the task. They were then asked to recall the list of words in the order that they came naturally to the participant.

Gray726_temporal_lobeCombining the brain scans with a model previously developed by the same research team, they were able to have a more accurate and reliable model that could better predict the order in which a participant recalled the list of words. Their findings indicated that participants who displayed brain activity in the posterior region (high fidelity) of the MTL when recalling a word were more likely to recall the word that was presented next on the list. For example, if the list order went “Horse, shoe, tennis, lion, hat” someone showing activity in this region would likely recall “horse” then “shoe.” On the other hand, people who displayed activity in the anterior region of the MTL (low fidelity) when doing recall may choose their next word from anywhere in the list, meaning they might say something like “horse, lion.”

These findings suggest that the brain uses what the researchers called a ‘temporal code’ to stamp memories. The brain is more easily able to recall memories that are higher in fidelity (the time travel memories) because they have these codes attached, and in turn the nearby memories, such as the next word on the list, are also more accessible to the individual. They described the process as similar to they way in which a computer is able to retrieve information when given a date and time to search for. When a memory is strong, like the time travel memories, the brain is able to search for and retrieve both those exact memories and memories of things that were nearby at the time of encoding simply because of the extensive amount of connections that time travel memories have made with nearby information.

I thought this study was really relevant with class discussion this past week as we have focused on the ways in which our memory systems work to encode and recall information. I think these are really interesting findings that help not only to form a link between brain areas and cognitive functions but they also demonstrate how our brains are working to encode that information in the first place. The original media article describing this research can be found here at Vanderbilt’s website.

 

1 thought on “Mental Time Travel

  1. schung2

    I read this post really well! I like the phrase “Mental Time Travel”. This post shows how much you understand what we’ve learned and what you’ve read. I liked the example “Horse, shoe, tennis, lion, hat”. This is easily, well, organized post that gives the readers informations extended to what we’ve learned in the class! I liked the memory recall and encoding part as well. Well done!

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