A glimpse inside the head of a 13-year-old autistic boy. The Reason I Jump: one boy's voice from the silence of autism by Naoki Higashida, David Mitchell, Keiko Yoshida. For parents, typicals, atypicals and everybody.  

David Mitchell's introduction to the book. It starts: "The thirteen-year-old author of this book invites you, his reader, to imagine a daily life in which your faculty of speech is taken away. Explaining that you’re hungry, or tired, or in pain, is now as beyond your powers as a chat with a friend. I’d like to push the thought-experiment a little further. Now imagine that after you lose your ability to communicate, the editor-in-residence who orders your thoughts walks out without notice. The chances are that you never knew this mind-editor existed, but now that he or she has gone, you realize too late how the editor allowed your mind to function for all these years. A dam-burst of ideas, memories, impulses and thoughts is cascading over you, unstoppably. Your editor controlled this flow, diverting the vast majority away, and recommending just a tiny number for your conscious consideration. But now you’re on your own."

From the book:
WHY DO PEOPLE WITH AUTISM TALK SO LOUDLY AND WEIRDLY?
...Honest, I want to be nice and calm and quiet too! But even if we’re ordered to keep our mouths shut or to be quiet we simply don’t know how. Our voices are like our breathing, I feel, just coming out of our mouths, unconsciously...

WHY DO YOU ASK THE SAME QUESTIONS OVER AND OVER?
...The reason why? Because I very quickly forget what it is I’ve just heard. Inside my head there really isn’t such a big difference between what I was told just now, and what I heard a long, long time ago. So I do understand things, but my way of remembering them works differently from everyone else’s. I imagine a normal person’s memory is arranged continuously, like a line. My memory, however, is more like a pool of dots. I’m always ‘picking up’ these dots –by asking my questions –so I can arrive back at the memory that the dots represent...

...it lets us play with words. We aren’t good at conversation, and however hard we try, we’ll never speak as effortlessly as you do. The big exception, however, is words or phrases we’re very familiar with. Repeating these is great fun. It’s like a game of catch with a ball. Unlike the words we’re ordered to say, repeating questions we already know the answers to can be a pleasure –it’s playing with sound and rhythm.

WHY DO YOU DO THINGS YOU SHOULDN’T EVEN WHEN YOU’VE BEEN TOLD A MILLION TIMES NOT TO? ‘
...How many times do I have to tell you?!’ Us people with autism hear that all the time. Me, I’m always being told off for doing the same old things. It may look as if we’re being bad out of naughtiness, but honestly, we’re not.

...we feel terrible that yet again we’ve done what we’ve been told not to. But when the chance comes once more, we’ve pretty much forgotten about the last time and we just get carried away yet again. It’s as if something that isn’t us is urging us on. You must be thinking: ‘Is he never going to learn?’ We know we’re making you sad and upset, but it’s as if we don’t have any say in it, I’m afraid, and that’s the way it is. But please, whatever you do, don’t give up on us. We need your help.
 

WOULD YOU LIKE TO BE ‘NORMAL’?
...for ages and ages I badly wanted to be normal, too. Living with special needs is so depressing and so relentless; I used to think it’d be the best thing if I could...But now if somebody developed a medicine to cure autism, I might well choose to stay as I am. Why have I come round to thinking this way? To give the short version, I’ve learnt that every human being, with or without disabilities, needs to strive to do their best, and by striving for happiness you will arrive at happiness. For us, you see, having autism is normal –so we can’t know for sure what your ‘normal’ is even like.

But so long as we can learn to love ourselves, I’m not sure how much it matters whether we’re normal or autistic.

WHY CAN YOU NEVER STAY STILL? My body’s always moving about. I just can’t stay still. When I’m not moving, it feels as if my soul is detaching itself from my body, and this makes me so jumpy and scared that I can’t stay where I am. I’m always on the lookout for an exit. But even though I’m forever wanting to be some place else, I can never actually find my way there. I’m always struggling inside my own body, and staying still really hammers it home that I’m trapped here. But as long as I’m in a state of motion, I’m able to relax a little bit.

WHY DON’T YOU MAKE EYE CONTACT WHEN YOU’RE TALKING?

...True, we don’t look at people’s eyes very much. ‘Look whoever you’re talking with properly in the eye,’ I’ve been told, again and again and again, but I still can’t do it. To me, making eye contact with someone I’m talking to feels a bit creepy, so I tend to avoid it. Then, where exactly am I looking? You might well suppose that we’re just looking down, or at the general background. But you’d be wrong. What we’re actually looking at is the other person’s voice. Voices may not be visible things, but we’re trying to listen to the other person with all of our sense organs. When we’re fully focused on working out what the heck it is you’re saying, our sense of sight sort of zones out. If you can’t make out what it is you’re seeing, it’s the same as not seeing anything at all. What’s bothered me for a long time is this idea people have, that so long as we’re keeping eye contact while they’re talking to us, that alone means we’re taking in every word. Ha! If only that was all it took, my disability would have been cured a long, long time ago …
 

Skeptics question this method of communication to which Mitchell writes in his second book (more on this here): "...he has learned to communicate by ‘typing out’ sentences on an alphabet grid –a QWERTY keyboard layout drawn on a sheet of card with an added ‘YES’, ‘NO’ and ‘FINISHED’. Naoki voices the phonetic characters of the Japanese hiragana alphabet as he touches the corresponding Roman letters and builds up sentences, which a transcriber takes down. (Nobody else’s hand is near Naoki’s during this process, a point that alphabet-grid communicators in a sceptical world need to restate ad infinitum.) If this sounds like an arduous way to get your meaning across, you’re right, it is; in addition, Naoki’s autism bombards him with distractions and prompts him to get up mid-sentence, pace the room and gaze out of the window. He is easily ejected from his train of thought and forced to begin the sentence again. I’ve watched Naoki produce a complex sentence within sixty seconds, but I’ve also seen him take twenty minutes to complete a line of just a few words. By writing on a laptop Naoki can dispense with the human transcriber, but the screen and the text-converter (the drop-down menus required for writing Japanese) add a new layer of distraction. It was via his alphabet grid or his computer keyboard that Naoki wrote every sentence in this book. [the second] "

You can see this in this Japanese YouTube video below which captures part of the process and Naoki's autistic traits.

Other articles and links of note:  Guardian Interview with David Mitchell in 2013; and David Mitchell interview in 2013 below. There is also