A team of scientists has uncovered a system in the brain used in the processing of information and in the storing of memories – akin to how railroad switches control a train’s destination. The findings offer new insights into how the brain functions.
The human brain and memory have been part of the many tricky mysteries that scientists have long been trying to understand. Along with the question of whether improving your memory is related to the average Intelligence Quotient. Why do people forget some things and why do they remember others? The question of why techniques like the memory palace allowed ancient Roman scholars to memorise entire books from front to back. Then there are the curious cases of world-known memory champions. These individuals, like Ben Pridmore and Joshua Foer, are able to commit to memory and recall remarkably large sets of data in a surprisingly short amount of time, all while claiming to have an average memory.
All similar memory aficionados will probably make the same claim. Boosting memory is a feat of purposeful action. The main difference they’ll report is the conscious effort in the process of committing to memory. However, there’s one striking deal noted in the several studies that scientists have published on the matter. When these individuals are asked to memorise or recall information, unique and established neural pathways light up. The common consensus is that their active efforts to utilize every bit of memory available to them have sparked the growth of neural networks that aren’t typically seen in those who don’t engage in such practice.
So, this kind of information suggests to researchers an interesting and intertwined link between the proficiency of one’s memory and the formation of neural pathways or circuits. It’s difficult to identify a memory under a scan, but understanding how neurons work in the brain could lead to a fuller comprehension of how the human brain retains and recalls information.
‘Researchers have sought to identify neural circuits that have specialised functions, but there are simply too many tasks the brain performs for each circuit to have its own purpose,’ explains André Fenton, a professor of neural science at New York University and the senior author of the study, which appears in the journal Cell Reports. ‘Our results reveal how the same circuit takes on more than one function. The brain diverts “trains” of neural activity from encoding our experiences to recalling them, showing that the same circuits have a role in both information processing and in memory.’
This newly discovered dynamic shows how the brain functions more efficiently than previously realised.
‘When the same circuit performs more than one function, synergistic, creative, and economic interactions become possible,’ Fenton adds.
To explore the role of brain circuits, the researchers examined the hippocampus – a brain structure long known to play a significant role in memory in mice. They investigated how the mouse hippocampus switches from encoding the current location to recollecting a remote location. Here, mice navigated a surface and received a mild shock if they touched certain areas, prompting the encoding of information. When the mice subsequently returned to this surface, they avoided the area where they’d previously received the shock, evidence that memory influenced their movement.
The analysis of neural activity revealed a switching in the hippocampus. Specifically, the scientists found that a certain type of activity pattern in the population of neurons known as a dentate spike, which originates from the medial entorhinal cortex (DSM), served to coordinate changes in brain function.
‘Railway switches control each train’s destination, whereas dentate spikes switch hippocampus information processing from encoding to recollection,’ observes Fenton. ‘Like a railway switch diverts a train, this dentate spike event diverts thoughts from the present to the past.’