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Player motivation, part 1: Biological foundation of emotions

This article serves only one purpose, explain in a simple way on how our memory works and how it’s affected by hormones and neurotransmitters. Why? To explain why and how psychological models works.

Andrii Honcharuk

July 21, 2017

15 Min Read

Instead of intro

Hello my name is Andrii Goncharuk, but you can call me Andy, I'm a game designer working in Ubisoft, and to be honest... I don’t know how I feel right now...

I’m having a hard time getting around my emotions and understanding my motivations, so I decided, maybe, I can apply some science to solve that problem?

I need you to play join me on that rollercoaster of emotions!

---   *disclaimer*   ---

I understand, that next topic is hard to get around with. I will try to explain everything as simple as possible so no one will go away from it with nothing in their head. Important to remember that some simplifications were made to make this information digestible. Check references for more details and scientific information.

---   *end of disclaimer*   ---

What the current problem?

In game industry there is a problem that almost all game designers want to solve once and for all, and there is no perfect solution so far(and that’s a good thing) for solving it.

1st problem is - how works player motivation?

In general terms psychology researches not players but all humans in all possible life situations and environments, but for sake of simplicity we will focus on players only. For players we can solve most of problems about environments and situations, because as game designers we partially control them.

There were many approaches, and will be more, from psychology and neurobiology to understand motivation process, and so far there are many different models that are applicable and partially working in some general cases. This scientific models themselves and their applications in industry will be in second part. For the first part I will try to solve second(on my scale of problems) greatest problem of game design.

2nd problem is - can we trust psychological motivation and other models, and if not, how can we check their credibility?

Any examples of a motivation model?

As example for motivation model I will use “self-determination theory” by Edward Deci and Richard Ryanе.



SDT stands on idea that human being have 3 basic psychological needs and when they specify need, Deci and Ryan, specify that this needs are in same line with hunger, thirst and other necessary needs for just being alive. Their researches and study showed that people limited by any of this 3 basic psychological needs will go crazy beyond normality and sometimes even die or end up killing themselves.

Here they are:

Autonomy - Need to be causal agent of one’s own life and act in harmony with one’s integrated self. Not independence or freedom just meaningful choices. Slave can be autonomous if he become slave by his own decision, or if he has ability to make choices that matter for him.

Competence - Need to control the outcome of one’s actions and experience process of mastering any of one’s skills. Becoming better in anything. Capable of doing something. Basic need on improving and become better you than previous you, at least in eyes of one’s personal consciousness and brain.

Relatedness - Universal need to interact with, be connected to someone/something, and experience caring for others or care from others. Care and be cared by someone or something. Be useful. Human that taking care of his own care, repairing, washing, upgrading it, talking to it(I know, weird right?), has relatedness.

All that sounds cool and interesting but, is it so?

Can we trust it?

How can we prove them right or wrong? It’s just a theory…

People always have doubts in applying something new, to solve that problem and to explain to metaphorical top management of a metaphorical game company that this model(SDT in this example, or any other model) should be applied during development process. Here we will dive deeper into how player(we decide to focus on player, remember?) brain works. And we will start from basics, real basics.

What is gameplay?

As one of the examples that really useful to use as references, cause it simple and give all necessary information, we will use shorthand diagram of atomic experience Daniel’s Cook gameplay model.


Player acts, game simulates a reaction and gives player a feedback, player updates it’s own mental model(knowledge, experience, understanding of something).

What is important to know here is that our brain constantly trying to predict future outcome of its own actions by running simulations based on already obtained knowledge.



Brain basic background process is simulating as many options as possible and choice one that will update one’s situation to a better condition in current timeframe, to choice option that will update one’s condition to a better one in future(long term goals) usually requires manual willpower modulation, this is why we are usually all lazy by nature.

This is also why we need to keep long term goals as simple as possible, and short term goals can be complex, since they will be solved soon enough and won't take to much brain power to hold on them for long time.

Simulations that our brain runs are always based on our previous experience, memories basically, our imagination is made only out of it, and we cannot imagine anything that we didn't seen before, if you try to imagine something that you didn’t seen before, it would be just a recombination of already known elements. In the end what is process of gaining experience? It’s reading memory, recording and rewriting memory, that mean to understand motivation it will be important to get our hands on…

How does our memory work?

Here we start diving deep into latest theories of neuroscience on how our brain works, to do so I’ll try to run really fast through core elements that necessary for our topic one by one. This part requires high level of attention!

We will start with basic concepts necessary for topic:



Neuron - basic brain cell. Synapses are the contact points where one neuron communicates with another with help of neurotransmitters. Neurons are cells within the nervous system that transmit information to other nerve cells, muscle, or gland cells.



Neurotransmitter - chemical that transmit signals across a chemical synapse, such as a neuromuscular junction, from one neuron to another "target" neuron, muscle cell, or gland cell. Most of the hormones are play role of neurotransmitters. Action of neurotransmitters is extremely fast, which could be up to few milliseconds. Hormones and neurotransmitters are really close to each other and most of them can operate both ways, neurotransmitter can function as hormone and vice versa (or start a chain reaction that will lead to production of one another, it’s important to remember).


Neurotransmitter can act as hormone, for example if you recall in your memory something scary or really pleasant it can result in chain reaction that will affect whole your body. Your blood pressure will rise, hands will sweat etc. Hormone can act like neurotransmitter, if you will hurt yourself(accidentally), your endocrine system will release endorphins(to harness pain), cortisol to mark event as stressful and adrenaline if there is threat of getting hurt more, in that situation your brain may react to it in a weird way, you can suddenly recall funny and pleasant experience and laugh(if endorphins will prevail), or you can become really sad and have according memories come to you(cortisol) or really angry if adrenaline will be more than others hormones.


Neurones are arranged in collections. Each collection of neurons arranged in a column(barrel), for sake of simplicity we will say that each barrel can hold up to many different concepts.

Concept - basic notions, like wheel, freedom or for example color red.

Barrels interconnected with each other. It’s important!

Combination of different possible states of neurons that forms barrel holds some data. Neuron state is recorded with a certain neurotransmitter.


Let’s imagine we have 10 different types of neurotransmitters that mean each neuron in barrel can be coded to 10 different states, so each concept is coded with combination like this {10, 02, 04, 10, 07, 03, 08} for example. That means that to read this notion your brain needs to produce neurotransmitters: 02, 03, 04, 07, 08 and 10 (This is VERY, VERY simplified, but this concept is enough for us)

Neurotransmitter spillover effect

Spillover effect video

When brain produce certain neurotransmitter, sometimes if concept recorded mostly but one type of neurotransmitter, it’ just simply too much of it and it’s simply spills over and activate neighboring neurons barrels that results in their activation.


When you jump out airplane and have all your life pathing in front of your eyes, this it, it’s simply adrenaline acts as neurotransmitter and activates chain reaction that activates all concepts that were recorded with adrenaline(mostly).



Emotions is a method of how our brain reacts to a certain neurotransmitters that active in our brain right now. Emotions are basically a flag for a memory cell, a color of it, if you want.

Memory can be colored with many different colors(mixed emotions), because memory usually recorded with many, many subjects and their recombination, but in most of the cases there is always a dominant neurotransmitter(color, emotion) that was used to record memory, and what most important this neurotransmitter will be needed to recall this memory, with a lack of required hormone(neurotransmitter), tries to recall certain memories will be effortless.




Imagine you have set of colored pencils and set of colored glasses, to read something that was recorded with red pencil you need to wear red glasses. And memories is just a simple book written with many many different colors, also after reading something you always erase it and rewrite again with more or less details.

Important (for game design) hormones!


Detailed work and effect of each neurotransmitter and hormone can be found in internet.

For our goals will be enough to remember simple example of player facing a problem:

I got a problem - body starts producing adrenaline

I can’t solve problem - body starts producing cortisol

I need to solve this problem - body starts producing dopamine

We have to solve this problem - body starts producing vasopressin

I found a solution to this problem - body starts producing serotonin

I will solve, for you, this problem - body starts producing oxytocin

I solved this problem - body starts producing endorphins

When player face certain situation body starts producing certain neurotransmitter, that also resulting in chain reaction if required amount is big enough, in simple words if emotion is very strong it will chain up other memories that you had in similar situation



Edward Deci and Richard Ryanеs unique magical psychological needs can be simply described as usual, boring biological needs in certain neurotransmitters for our body to simply operate normally (read and record certain memories):

Autonomy - is a strong need of vasopressin, mid need of dopamine and serotonine and a little bit of oxytocin.

Competence - is a strong need of serotonin, mid need of adrenaline and dopamine and a little bit of endorphins.

Relatedness - is a strong need of oxytocin, mid need of dopamine and vasopressin and a little bit of serotonin.

Knowing your audience allow  you to  research for example what concepts associated with what neurotransmitters.

I will give quick and very simple example that most of the people can relate:

mother, father, son, daughter, brother, home, first kiss - concepts usually recorded in brain with oxytocin and vasopressin.

Why cultural? Because most of color codes for concepts and memories are cultural things, there is no presets with which baby is born. This is one of the reasons why it’s necessary to know your audience and their usual life from birth till now. To know what concepts are recorded with which hormones.

As example you can compare certain cultural differences and reactions to color red in western and eastern countries.

Flow and game pacing through prism of neurobiology



Many of you probably seen this graph already, which I personally think is useless, without understanding how really control player experience and emotional stance, boredom and anxiety.



Narrative pacing graph, again can be useless without understanding how create drastic changes in emotional stance of a player.

With good working model of how memories and emotions works this two graphs can be applied more efficient.

If we need to ensure that experience of a player is smooth, concepts presented to player must be placed close to each other in meaning of mood and slowly go from one to another.

If we need to make a drastic changes and fast growing pacing experience, we just need to insure that player will get concepts that will be antagonistic to current, bigger contrast in neurotransmitters and ever growing strength of them will result in feeling of fast paced experience.

Simple example of contrasting different neurotransmitters on example of imaginary intro video for a 3D fast paced action game:

  1. Hero slaughtering armies of monsters on battleground

  2. Forest, mother and little boy passing by camera, holding hands and laughing

  3. Hero breaking legs of huge enemy boss monster

  4. Ship filled with goods and grown boy saying goodbye to his mom on a pier

  5. Hero making his final blow, crushing skull of a huge monster boss, blood!

  6. We see a young man checking picture of his mother and hiding it in pocket

  7. Ship from arriving to a burning village where boss that was killed already in previous scene slaughtering villagers

So what now?

This article serves only one purpose to explain one of the latest theory on how memory works and how it’s affected by hormones and neurotransmitters. For what? To explain why and how some psychological models works, this knowledge won’t give clear tools how exactly game can be improved, but knowing how experience and emotions are interconnected, in my humble opinion is important.

If after reading this article you feel that it can help you in your work, I will strongly suggest to dive into provided references, there you can find much greater details on all topics that were provided above.


  • Knowing players motivation is problem

  • It’s hard to persuade people to apply psychological(magical) models in gamedev

  • Self determination theory is basically: autonomy, competence, relatedness

  • What is gameplay, predictions and updating mental model

  • Memory is REALLY complex thing

  • Emotions and hormones affects memory a lot

  • Adrenaline, cortisol, dopamine, vasopressin, serotonin, oxytocin, endorphins

  • Flow and game pacing important elements of game

Bonus level

To the all the tinfoilhat wearers, here is list of known and registered neurotransmitters:
















Vasoactive intestinal peptide

Growth hormone


Neurokinin A

Neurokinin B

Substance P

Neuropeptide K

Adrenocorticotropic hormone




Gastrin releasing peptide


Nitric oxide








2-Arachidonyl glyceryl

N-Arachidonoyl dopamine



Adenosine triphosphate


Galanin-like peptide




Neurophysin I

Neurophysin II

Neuropeptide Y

Pancreatic polypeptide

Peptide YY





Orexin A

Orexin B




For most of the neurotransmitters effect on brain is not studied yet, and new neurotransmitters will be found(probably), so we far far away from mind control and emotion suppression(I hope).

Presented above knowledge can help us make better games.


Self-determination theory


Engines of Play: How Player Motivation Changes Over Time


The Chemistry of Game Design


Throwing Out the Dopamine Shots: Reward Psychology Without the Neurotrash


Cognitive Flow: The Psychology of Great Game Design


Holonomic brain theory


Barrel cortex


Synaptic transmission: Spillover at central synapses




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