Meet the basal ganglia. . . a substrate for motivational scaffolding

The basal ganglia are is a group of structures nestled under the cerebral cortex.  What exactly the basal ganglia do remains controversial and subject to intense investigation.  They seem to be play a critical role, though, in a laundry list of neurological and psychiatric disorders, ranging from Parkinson’s disease to addiction to attention-deficit hyperactivity disorder and obsessive-compulsive disorder to, more recently, obesity.  That, together with the fact that they take up a fair amount of neural territory, suggests that whatever they do, it’s probably important.

An illustration of the location of the basal ganglia within the brain.

Historically, the basal ganglia have been thought to mediate two primary domains of function.  On one hand, they have something to do with motor control and motor learning, hence their role in Parkinson’s disease.  On the other hand, they seem to have a lot to do with motivated behavior, the link to addiction and obesity.  These two areas come together in what is now the predominant view:  the basal ganglia are structures that mediate reinforcement learning—that is, learning from reward— and contribute to selecting actions.  Referring to the last post, in the basal ganglia motivation and action are married, two peas in a pod.

What’s this have to do with video games?  There are three functions associated with the basal ganglia that are worth highlighting.

First, procedural learning.  There are several types of learning and memory.  There is declarative memory, such as remembering the capital of Idaho is Boise: facts and information.  There is episodic memory, such as what I had for breakfast or where I was in 2003.  And finally, there is implicit or procedural memory, which is memory of how to do things, motor memory of sorts, the sort of memory and knowledge you are not necessarily aware of.  Though video games may require all three types of memory, the lion’s share of mastering a video game is, generally, skills.  That is, within the game world, you learn how to do things.  From an evolutionary perspective, you have to respect this kind of learning.  Very few animals need to remember where they were in 2003 or, for that matter, what they had for breakfast.  Even fewer need to know the capital of Idaho, including most humans.  But how to do things, no organism can survive without that.  All the neural machinery in the world and all the learning that goes with it is of little use if you can’t learn how to take actions and do things.  Motivation isn’t much use either if you don’t have the ability to do something when motivated.  So the basal ganglia are all business, it’s about doing, not lots of useless fancy cogitating about state capitals and breakfast.

Second, the basal ganglia are associated with reinforcement learning and regulating motivational processes.  This is, in some ways, an extension of the ‘learning to do,’ no-nonsense, get-to-business attitude of the basal ganglia.  In a word, they do what works.  When an action yields reward, it is remembered.  There’s no la-de-da, am I motivated, what should I do sort of equivocating with the basal ganglia: they act first and ask questions later, mainly ‘was that a good thing to do?’  If the answer is yes, they remember and learn that action.

Third, the basal ganglia have been associated with habit.  Habit is essentially a behavior that happens automatically without much, if any, conscious thought or deliberation.  It is a response that is under ‘stimulus control’; that is, like pressing the brake at a stop sign, it’s an action that occurs automatically in response to events in the world, kind of like a learned reflex.  In a way you might think of this as the no-nonsense basal ganglia cutting to the chase: we’ve been through this many times, you don’t need to think about it, here is the best action to take. . . done.  This is the sort of learning critical for things like riding a bicycle, mastering a tennis serve or tapping the controller just right to dodge the death traps and kill the monster.

So returning to an earlier post, in appealing to a broader audience with a video game, particularly when motivation to play may not be present initially (eg., educational games), part of the challenge is to create motivation.  The basal ganglia represent potential neural substrates or brain mechanisms for scaffolding motivation, presenting a sort of triumvirate of motivational development: reward, action and automaticity.  In the next post I will look at how and why these three are related before returning, at last, to our original topic– inducing habitual game-play and the creation of motivation.