So I’m going to say it right now, I’m a big fan of neuroscience, psychology and everything else that might give an edge on cognition. 

Furthermore I’m an avid gamer, playing on almost any console released in the last 2 decades 

(PS1, PS2, Xbox360, XB1, PC, PSP, PSVita, GameBoy Color, GameBoy Advance, 3DS, SEGA Genesis, and some Nintendo NES knock-off, basically a big list) 

and Genres 

(Action, FPS, RPG, MMORPG, RTS, Card Games, Fighting Games, Puzzle Games, aka another big list).

And understanding how the latter impacts the former is an important task, ney, mission, as far as I’m concerned. 

And there is reason for concern, which definitely may shock you 

(just kidding, this isn't a clickbait article), 

So yeah,  the whole video games - cognition relationship isn’t as black & and white as most of us think.

Since it took me close 8 hours to finish this post, I’ll be presenting only one main research paper, and a few small researches in case some background information is needed.

And with the background we begin: a brain structure called the hippocampus (no, not a college attending hippo, as the name might suggest) has numerous cognitive responsibilites, starting from semantic and autobiographical memory, to spatial navigation, and it even has a major part in regulating and processing emotions! So there are plenty of reasons we would want our college attending hippo to be big and strong (connected to many other neurons with stable synapses).

So the research I’d like to present tried to tests several interesting hypothesis:

1. How do 1st & 3rd person shooting impact hippocampus growth or atrophy (shrinkage)
2. How 3D Platformer games (E.G Mario 64) impact it
3. What is the relation between the hippocampus & Action RPG games such as Dead Island & Borderlands 2
4. And finally whether spatial & response navigation strategies change the outcome after playing said games

Spatial & Responsive What?

You see, there are two main ways to navigate both in the real world, and a virtual one.

• A spatial way - building a cognitive map of your surroundings and figuring out the path from point A to point B by using the map in your head
• And a responsive way - counting the steps from one turn to another, and possibly memorizing how the area before a turn looks like

Can You Guess Which One Is Healthier?

17 Action Gamers (those who play games like Call of Duty, GTA V, Counterstrike, Tomb Raider, Gears of War and such, for at least than 6 hours a week) and 16 people who never played Action Games in their life. Both had their brains scanned through an MRI machine.
“Significant differences were found whereby actionVGPs had reduced grey matter in the left hippocampus compared to nonVGPs, ”
While they compared the average hippocampal volume on Action Gamers VS Non Action Gamers (or generally Non Gamers), they found that the hippocampus on the left hemisphere was smaller in Action Game Players.
The left hippocampus is actually associated with verbal memory, while the right is the one mostly associated with spatial and visual information. Weird.
So playing lots of action games MIGHT impact your ability to memorize facts for a test, and even to remember new information about your friends, family, and people you have strong negative or positive feelings for.

Additionally the researchers compared differences in 4 groups of non action gamers:

1. those who trained 90 hours in action games, and were response navigators
2. those who trained 90 hours in action games, and were spatial navigators
3. those who played 90 hours in 3D Platformer games, and were response navigators 
4. those who played 90 hours in 3D Platformer games, and were spatial navigators

The results were baffling:

• group 1 had a reduction in volume of their right hippocampus (seen to be correlated with non-verbal memory)
• group 2 gained an increase in volume of the left hippocampus, which oddly enough is mostly correlated with verbal memory
• group 3 had gains in the right hippocampus, suggesting that certain games force players to make cognitive maps, even if their default navigational strategy is a responsive one
• and group 4 actually had a gain of volume in the right entorhinal cortex, which seems to be crucial in association tasks, but not in “single object” memorization tasks

Action RPGs - Elixirs or Poisons?

Lastly the researchers measured differences in hippocampal size of non action gamers before and after they have played 90 hours of Action RPG games such as Dead Island and Borderlands 2.

And when people ask you what’s your (gaming) poison, I hope your answer was not actionRPGs. Because, and I quote “This revealed a bilateral decrease in the hippocampus at post-training across all participants”, 

in other words, 

whether you navigate visually, by building a cognitive map, 

or memorize distances between checkpoints along the way, 

your memory generating hippo will not be happy with you if you play Borderlands, Dead Island, or God forbid, World of Warcraft.

I’ve been working on this text for almost 8 hours, so if these kinds of analyses interest you, please give this post an upvote (even a 1% upvote will do), so that I'll know how big of an audience is there for academic pieces like this.

Sources

Main research paper with action, 3d platformer, action RPG and navigation type comparison https://www.nature.com/articles/mp2017155?foxtrotcallback=true

Brief summory if hippocampal functions                                                                                                 https://www.news-medical.net/health/Hippocampus-Functions.aspx

Emotional processing and you                                                                                               https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3340463/

Hippocampus volume reduction in various mental disorders                                      http://pubmedcentralcanada.ca/pmcc/articles/PMC2840841/

Synapses explained                                                                                                                      https://www.britannica.com/science/synapse

WTF is atrophy?!!!                                                                                                                       https://www.britannica.com/science/atrophy

Hippocampal functions variability on the left and the right hemisphere                    https://www.sciencedirect.com/science/article/pii/S0896627302008309

Emotions impact on memories formation and retrieval                                                                   http://www.memory-key.com/memory/emotion

Visual memory impairment in people with right hippocampal damage due to right temporal lobe epilepsy https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2170342/

Higher activity in left hippocampus while memorising a list of words, higher right activity when memorising pictures                                                                                                                                                    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC182590/

Entorhinal Cortex lesions cause impairments in associative memories in monkeys          http://www.jneurosci.org/content/24/44/9811

An example of tasks Entorhinal Cortex lisions impaired                                                      http://psychology.jrank.org/pages/467/Paired-Associate-Learning.html

 Tasks the Entorhinal lesions DID NOT impair                                                                               www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_11/ch11p4.html 

Image Sources

https://obssr.od.nih.gov/video-games-as-a-prescription-to-enhance-cognitive-function/

https://en.wikipedia.org/wiki/Hippocampus

https://www.dreamstime.com/stock-photo-path-point-to-point-b-vector-illustration-image36432080

http://www.wowhead.com/item=9179/elixir-of-greater-intellect