Autistic brains analyse bottom-up, while other people their brains analyse top-down.
In one of the books about autism that I have, their is a picture that illustrates this perfectly. It’s an illustration of a forest with the trees vaguely drawn but all the little details like a mouse and mushrooms are drawn in great detail. The explanation next to the illustration was the following; When a person with ASD walks into a forest, his/her brain starts to collect information to create a context just all the other kinds of brains do, but the autistic brain starts at the bottom. First it sees the mushrooms, then some leafs, a bird flying by, the bushes, … Meanwhile the not-autistic brain in the same situation will notice the large group of trees first. The non-autistic brain will think “Ah a big group of trees, this is probably a forest”, and then goes on searching for details that confirms this and adds more information. At the same time, the autistic brain still doesn’t know it is in a forest, however, it does know it is somewhere where there are mushrooms and wild animals. The brain will continue to look for details until it finally reaches the point it notices the trees and other obvious signs you are in a forest.
TL;DR/ An autistic brain uses details to create a big picture of a situation. A non-autistic brain will use the general context to create the big picture.
This difference in processing information has some consequences, like @marxism-sjwism already mentioned.
Other occurring ‘problems’ are f.e.: doing tasks slower, getting tired easily*, becoming overstimulated when there is too much information, headaches, intolerant of bright colors/loud sounds/touch/smells/taste**, having difficulties doing a certain task because the details weren’t explained to you, getting stressed out because a detail changed in a situation***,…
*Because an autistic brain processes a lot more information than any other brain, it also demands a lot of energy from its body. Sadly, the human body can’t provide the energy this kind of brain needs. As a result, most, if not every, person with ASD gets tired quickly and needs hours, or even days, of relaxation to reload its batteries. Especially after big events like going to a party f.e. (I myself need a lot of sleep).
**Because the autistic brain gets its information from details, it has hardly any filters. When a non-autistic person is at a party and talking to someone, his/her brain wil cancel out other inputs so it can focus on the conversation. An autistic-brain doesn’t do this, or if it does, it isn’t doing a good job. When a person with ASD is at the same party, talking to the same person as the the person without ASD, he/she will have difficulties understanding the conversation and keeping focused, because the brain isn’t canceling out all the other information. The conversation a nearby group of people is having will be equally as loud as the conversation he/she is participating in. This also means that a person with ASD can get easily distracted. F.e.: I was talking with someone, when suddenly I could hear two people talking in the room next door. It was a muffled noise and I could not understand what they were saying, but it was enough to distract me and render me unable to keep focused on my own conversation, resulting in me forgetting what I was saying mid sentence over and over again. Anyway, worst case scenario, if there is to much information for the autistic-brain to handle, it will become overstimulated, and this overstimulation often results in a fight-or-flight reaction. This behavior is often illustrated in mainstream media by an autistic child who suddenly becomes unmanageable, crying, kicking, screaming, … often at public places like a supermarket. Not every person with ASD will throw a tantrum when becoming overstimulated, some shut down, some start crying (like I do), some get angry, … It’s important to understand that this person is not being an asshole because he/she wants too, or that the child is not badly raised. These people their brains have triggered a natural instinct and their is nothing they can do about that except obey it. Best thing to do is to remove them from the situation to another less stimulating environment where they can calm down.
***Last but not least, there is another important consequence of having a brain that gets its information from details: it doesn’t recognize a same situation when a detail is changed. This causes difficulties in many different kinds of situations and it can occur in many different ways. A person with ASD will find it difficult to drive a different (brand of) car than he/she is used too, because, even though it’s a car and all cars operate the same, small details like a different dashboard layout can be confusing and stressful. A more extreme example is when the barman in a pub you frequent always wears a red shirt, but one day he wears a blue one. The change in color is enough for the autistic brain to think this is a completely different and new situation and thus it operate as if this is a new situation. This is why people with ASD can be insecure in situations that should be no big deal. Or why people with ASD seem to forget how to do a certain task, or lose their shit while any other person quickly adapts, all because something is different. Or also why they keep asking for explanation on how to do a certain task even though they have been doing it for months.
All these things are mostly downsides of having an autistic brain but it also has its benefits. People with ASD notice details much easier and faster which can come in handy when doing certain jobs. They also make different connections and come to new ideas that others never would’ve thought of.
The work they do is often more correctly because they pay attention to details, include details, or want to make sure it is 100% the way it should be because their brain only takes peace with that. Consequently, a lot of people on the spectrum also have a high sense of justice and are good detectives, insurance agents, police(wo)men, lawyers, mystery shoppers, …
A brain like this makes these people also excellent at IT, gaming, art, music, programming, math, bookkeeping, science, sorting, systematization,…
Sadly, people on the spectrum are often still seen as a problem instead as and added value. Like Temple Grandin often says; The world needs to realize it needs different kinds of brains to work together to reach greater heights.
