Mentioned by a World Memory Champion in Moonwalking with Einstein, it was elucidated that evolution has
played a role in developing our memory to be extremely powerful when it comes
to spatial orientation. For many years, humans have had to rely on visual cues
to get us where we are going. A key
trick in easy memory recall is placing, say, grocery list items within a
well-known environment like your house or a path you travel daily. So how
exactly does our brain use these areas we know so well to help us remember
things like our shopping list?
Last year’s Nobel Prize in Medicine/Physiology was given to
three people who provided the bases for cells that behave like an internal GPS.
These cells are known as grid cells
and help orient mice in a room when they collaborate with place cells. The place cells
are within the hippocampus, the part of the brain infamous for memory. These
grid cells and place cells are part of a network within the brain that helps
develop memory.
figure
from Nobel Prize Press Release for 2014 Laureates in Medicine/Physiology
An article published in Neuron
determined that the grid cells could utilize other mechanisms than just visual
cues to provide orientation though. The cells were firing action potentials
that allowed the mice in the study to understand distance along with time while
running on a treadmill. This means that these specific cells within the brain
are responsible for integrating space along with time, creating an
understanding for what are called episodic memories. Episodic memories are our personal memories
recalling events that have happened in the past, with reference points of location,
along with a specific time. Not all our memories have to be correlated with
location, but can also use references of time.
Studies conducted with human subjects shows that recall of
events often activate the part of the brain that provides the spatial context
for the memory. In short, the hippocampus utilizes the cells that are also
responsible for location. However, this is only one part of the puzzle and the
pieces that explain how these cells truly affect memory still needs to be
determined.
For the fate of my intermittently lost keys and phone, I
think it’s best to continue utilizing my place cells to retrace my steps.
Thanks for posting Jenny! This is very interesting and something that is worth looking into. I am also guilty of being very forgetful and misplacing things. I've noticed that these sorts of things happen to me more often than before. I would be looking for my keys but turns out, it was hanging on my neck for the past 10 minutes I wasted searching my entire apartment for it. It appears that age and even mental stress could be a determining factor as to whether or not those grid cells are actually functioning to its full capability. It sounds like these cells are developed for long term memory where there's repeated firing of the AP to generate that long term memory effect. Placing your phone down somewhere or hanging your keys on your neck seem to be only temporary and may also not trigger any stimulus to these cells. I would think these sorts of actions are insignificant to most people considering the million other things we have going on at the same time.
ReplyDeleteThis was a very though provoking article as I am also very directionally challenged. I definitely agree with Nicole in that stress plays a major role in grid cell functionality and capacity, and I was wondering if maybe sleep deprivation would contribute to lack of memory recall as well? However, after some shallow initial research, there seems to be a current debate about whether sleep actually has an effect on memory. One study claims that lack of sleep has no effect on short term memory recall, such as misplacing an object or recalling someone's name (1). Another study suggests that although lack of sleep has not been shown to play a role in short term memory, that it may greatly be a factor in long term memory (2). Just from personal experience, I know I can think better when I am feeling rested, but I think I will always misplace my keys or phone on a regular basis.
ReplyDelete1. http://www.ncbi.nlm.nih.gov/pubmed/1141831
2. http://www.tandfonline.com/doi/full/10.1080/09658211.2013.778294