So what really is happening in autism people, when you consider from advaita perspective? Advaita says everything is Maya, illusion. And only that principle which perceives (and which we end up calling "I", and associate it wrongly with body) is what is there, and when we stop identifying ourselves with limited boundaries (of body or any knowledge), we can perceive a reality beyond all illusions.
"He scans a page in 8-10 seconds; which we take 3 minutes.", says the person who interacts with him in the above. No "serial" processing; just some focus and the guy gets it all. It is not that eyes read it serial, but in faster pace. It is just that the perception is interpreted in very different way; kind of fast image analysis.
So usual focus of researchers is to find the way brain is operating in this person. In a "usual design" of a human being, consciousness perceives only that reality which is presented via brain. It limits itself to brain. Before we want to get something into the brain, variety of filters are put in... making it a highly serial process. Everything needs to be first "connected" to what is already stored. And that storage is highly concepts based.
But consciousness doesn't have to limit to brain, it can perceive any reality; like we can perceive how a computer program is running, and what is actually happening inside a system. Not everyone can perceive that, but only those who went through creating a set of concepts... And what made you understand a concept as a concept? For e.g. a tea cup being distinct from the porcelein material, and having a set of other concepts (like its association with liquid)? Using basic concepts (in advaita they are actually called Tatvas) the whole universe is born. But consciousness is not content, it is the fundamental principle which gives reality to something, that which gives rise to "I" in us. It is the experience of the taste, or the colours perceived by the eyes.
Consciousness, by its very nature, can directly access the abstract reality which holds all concepts and relationships. Or things like sequences of pi. In a normal human being, the expression of consciouness which has all kinds of layers and layers of limitations. For e.g., you introduce a concept called brain in the infinite, and then see the infinite through finite brain. And then it filters through the reality perceived through senses. And then you filter through previous experiences that body has. And then the logical layer within the humans, which starts to reconstruct the nature of reality from scratch. The layers go on and on.
But in Savants, may be because they aren't subject to logic the way we do, can effectively get a glimpse of that reality in a different way. Much less layers. Sometimes scientists get a glimpse of reality cutting through layers. Sometimes, reality makes it through layers. These days, computers give access to deeper reality since they operate without those layers. That is why you are sure that the value of Pi generated by computer is indeed so. You have pathways within the accumulated knowledge which ultimately lead to the pristine reality. So to really know if computer generated value of Pi is indeed so, you verify the algorithm in certain way. Some psychics can perceive the reality - not just what has happened, but what is going to happen. Consciouness just gives access to that ultimate reality in which everything is laid out like a song is laid out on tape.
Expression of Pi, or multiplication of numbers is quite a direct access to reality. The savants are generally are able to do it quickly. But they can't do things which involve deeper and deeper set of concepts. A deeper symbol processing is needed when you come to realize that such-and-such-person is friend of your friend's friend. This process of "making sense" and connections in the existing data is somewhat different sort of activity that savants can't probably do, but most humans are apt at it. Why? because the whole of interface has accustomed to using logic in such a way that you tend to extend the existing reality in meaningful way. (It is different interpretation as to what "meaningful" means to us; but it has something to do with security and well-beingness.) For e.g. doing your office activity to achieve well-defined objectives, to create a new research theory or to act in a movie - these are all senseful activities. When you are not bound by such everyday objectives may be there is opening for different perception of reality. Suppose you accept to become a mad person, you are still consciously acting with sense. If you end up becoming mad (without your choice or logical mind involved in that process), may be different aspect of reality can be experienced.
If one wants that experience in controlled manner, then one probably heads to variety of ashrams in India! But when one understands futility of any experience and sticks the principle itself (which Nisargadatta calls "I am" principle), then consciousness has to abide in itself. What you then have is not any content or logic, but the primordial principle that has creation, maintenance and destruction in itself; beyond five elements or time or space. Well, this is what some of the enlightened say... and there is enough material and evidence that points to that... One simply has to decide to dwell into it; and everything - including logic etc. has to drop. It doesn't have to make you unconfortable in this world though... Consciousness can take care of itself.
There are various questions that researcher will ask. For example, how does consciousness remember what it has experienced, if it is not using brain? It must store it somewhere! What is it that allows us to put a boundary for perception, when there is no boundary in physical reality? If my eyes are seeing a computer and a program running in it, obviously physical aspects are immaterial. It is the model/image that we (apparently) build in our brain that is important... And our consciouness is moving within that storage in brain. Then again, how are we able to put a boundary? How are we able to only focus on some things of that storage? For that matter, how are we able to shift our attention from forest, to the individual trees, and leaves and cells of the tree? This boundary formation is continous thing ... that is the most mysterious process that exists there. Advaita says that there is no boundary at all i.e. everything (and not just what is in brain) is available to consciousness as pure knowledge, and the boundary, and the space, and the time, and the interpretation, and the very sense of this world, everything comes in at once. That is the moment of creation. Creation is not in space or time, but creation means creation of space and time. Every moment is creation. The thought and other aspects then join those moments into continuous whole, but there is no whole. Autism people can switch randomly between the abstract reality and give us the flash of what it is like to live... But alas, they don't have control over that process... May be some yogi's have.
If you have this lifetime, what else is important, other than to get to the mystery of whole existence!