Here is a photographic difference between a normal brain and an addicted brain.
And what does it mean? Please, clarify for those who can't watch full video. From the what I see, some central parts of Joy's brain became "colder" . But the question is what this parts are responsible for.
But thx, when i'll see such tomographic picture, I ll know that this person is addicted
I am not a medical person but a good explanation can be found in this article[1]. That part is the reward center of the brain.[2]
There is thre different types of behaviour for thre categories of gamblers.
1. For gambler who gambles for entertainment, this type of gambler does not gamble with big money since he is more concerned with happiness more than money.
2. A good gambler but not an addict, this type of gambler feels so bad after lossing money and may feel depressed and this gambler might stop gambling after losing big money.
3. An addict, this type of gambler is used to winning and lossing to the extent that if he losses, he will see it as a sign that big winning is on the way.
I think this fall to type of gambler, as far as I know there are 7 type of gambler and it is explained here.[3]
That's the sad truth for those types of gamblers that can't accept defeat, they really are likely to spend every resource that they have until they recover.
But, it's all just in their minds, and recovery from such a big loss is hard to achieve because as you've said gambling is unpredictable and those who try hard will keep losing, financially and emotionally.
True, this type of gambler is very selfish, they are not ready to accept defeat. In fact, gambling is like a double edged sword, winning and losing. Professional gamblers also experience defeat very often and such conditions have often been experienced by any gambler.
When you decide to gamble, be prepared to accept defeat. There is no need to blame anyone for the recent defeat, because defeat is a risk that gamblers must accept.
They aren't selfish, they are too generous because they are giving away their money. Not accepting defeat is not a good definition of selfish. They maybe persistent. But in gambling terms, they are addicted since they keep on chasing losses until they run out of resources.
[1]
How do Addicted Brains Differ from Non-addicted Brains?[2]
https://youtu.be/03kQXimVcrw?t=265[3]
https://bitcointalksearch.org/topic/what-type-of-gambler-am-i-5403930