Is there a limit to how much information the brain can take in at a time?

Kinda a weird question, but is there a limit to how much information you can take it? For example: if I have 100 reviews would it be better to do them in 2 different 50 review sessions so that I have more time to “digest” the information or is one 100 review session just as efficient?

I don’t think anyone who is not a neuroscientist or linguist can adequately answer the question in the title, but I sure know the answer to your practical question. No, I don’t think the length of your review sessions effect your retention rate, or at least my brain’s limit is not 100 reviews per session. I consider myself to take WK at fairly mild pace, and I have an average of 90 reviews per day, and most of the time I have 1 review session per day. So “digestion” isn’t really something you should be worrying about, I think. If it’s more comfortable to do 2 50 review sessions instead of 1 100, then go ahead. Whichever is preferable to you.


Everyone is different and I think you’ll have to figure out the answer for yourself but I can tell you that yes, for my brain there definitely is a limit. Maybe something like 20 lessons and 50 reviews. After that, ideally I need a break.

I can of course do more reviews but either I get tired or just lose motivation and don’t focus properly and the quality goes down (stupid mistakes, not reviewing information in detail when I get something wrong, things like that).

The limit will also vary on the time of day, level of stress that I have in my life, amount of sleep I’m getting… And e.g. walking outside while doing reviews helps me to stay fresh and motivated for a longer period of time. (That is at least something for which I’ve seen studies: there seems to be a positive link between cognitive function and exercise).


I think what’s more important is how much time and energy you can devote to each individual item. If you can spend the time needed to read the mnemonic, practice saying the word aloud a few times, reading the example sentences, maybe writing it out… then you should be able to solidify the item quite well.

If you try to do 100 new items without doing something like that, then it probably won’t stick very well.


the faster you do your reviews, the faster you will level up, the faster you level up the more lessons you will have. the more lessons you have the more learning your doing.

If there is it is not possible to know. true learning happens on a subconscious level. and it’s really difficult to know how much is being taken in. if you can do a hundred reviews then do them but if you can’t do the 50. but you will learn way more if you did 100 reviews. but you may feel like your getting a lot more wrong doing 100. but really your learning way more subconsciously.

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I think either way, be it 100 at a time or 50, your brain is digesting at least some information. It just depends on how much you wanna challenge/torture yourself. :slightly_smiling_face:



the faster you do your reviews, the faster you will level up, the faster you level up the more lessons you will have. the more lessons you have the more learning your doing.

I think leveling up is not the same as learning. Sure you can’t unlock new items without leveling up but if you don’t retain older items, what’s the point? And rushing will surely drop retention rate.

I usually can do about 15 kanji lessions or 30-40 vocab lessons per day. And reviews are easier, since I don’t need to memorize new info, so even 100 per session is fine.


going slow messes up Wanikani SRS system. because it’s timmed to give you reviews when your about to forget them. so the longer you put off reviews the more likely you are to forget them.


But there is a difference between “let’s take a break for a few minutes or an hour to let our brain rest and regain focus so that I can do my reviews properly” and "let’s not do our reviews and let them pile up until there are 500+ reviews waiting for us.

Going fast is fun but going too fast is the easiest way to piles of reviews of items that you have barely learned. And then, if something gets in the way, those reviews get unmanageable very quickly. At that point you’ll really be messing with the SRS, just like you said.


I’m not a neuroscientist either, but I read that your brain distinguishes important information and not so important information. For example, if you live in Japan and your only way to survive is to learn, you will be great in no time (say you attend lectures and must hand in your homework in Japanese, or you work using Japanese). Your brain will grasp the language faster.

On the other hand, dumping information with WK without a “need” will tell the brain to pretend to learn a bit, but forget everything at the first opportunity (like taking a few days off from WK).


I think it’s rather an individual time limit. For how long can your brain stay intensely focused on learning? Because forcing yourself to do reviews when your mind wanders off might be the point where you want to take a break. That could be after 50 or 100 reviews or 200!
A teacher once told my class that after 20-30mins it becomes hard to concentrate on one task, and so we never spend the whole lesson on one topic. I have no clue of scientifically accurate that is but for me personally it’s usually the case that I lose focus after about half an hour.


I’d say, it depends on the person. How do you feel after a hundred reviews? Still fresh and eager for more, or does your brain feel tired and foggy?

I can do a hundred reviews in 15 to twenty minutes and still feel happy and fresh, so it’s no problem for me. Afterwards I look at all the items I got wrong to reinforce them. That takes maybe another 5 to 10 minutes, depending on how many new items I got.

You could do some experiments and track how it influences your error rates :slight_smile:

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I prefer to do no more than 50 reviews in an hour. It works better for me than doing 100 because I start to rush/make mistakes if I do that many.

Also how easy are the reviews right now?

If you’re zipping along, answering everything correctly with no hesitation then sure, keep on going!

If you have to stop and think about each item – or even worse, if you get a lot of items wrong and have to reread their mnemonics – in those cases it’s better to do small batches so the information can sink in.

That is partly true. But WK’s intervals are not precise to the minute, especially at the higher tiers. You can delay half your morning reviews until the evening and it won’t break the system. In fact, it’ll even help you if your brain is more alert and less rushed during the late reviews.

Hey, I resemble that remark! :sweat_smile:


Yeah. What everyone else said.

I can do reviews until I can’t. Or want a break. But if you stick with WK, it’s going to probably end up being a daily load of a lot more than 100. 100 to 150 at a time becomes a twice a day thing, or right around it. Or worse. It’s just like a super long quiz. I don’t really worry about wrong answers anymore. (OK, that’s a lie, I still hate getting things wrong.) I just type the next answer. Or I guess. And then the next one…

A more interesting question is LESSONS. How many new things can you actually learn for the first time? When I finish 150 reviews, and then switch to lessons, I often feel a sense of mental “fullness” after just a few new lessons. Like, I simply can’t learn one more thing! But I’m usually wrong, so I try to push myself to just “finish this set of five”, or “do five more than I think I can”. And it works, for some reason.

There might be a limit to what you can learn, but it’s probably a lot more than you think it is. Be brave. Do your reviews.


I just read down a bit and wanted to up-vote this because I realized after speeding through wanikani content and burning out a couple years ago that it’s better to take your time and study more deliberately than to level up and hope your subconscious just glues Japanese and English together in your brain.


I think even a neurologist wouldn’t be able to answer this question for you, it’s too individualized. Like maybe there’s a limit but it’s so far off the standard bell curve like an asymptote stretching towards infinity.

Everyone on here can tell you what feels comfortable to them, but I think our limits are usually higher than we think.

I’m a newbie, so maybe I’ll be eating my words in a few months, but I think the most new lessons I’ve done at a time was ~120 and that’s still been fine, just took longer than I typically spend at a time studying. I typically have 100-150 reviews per day and that still feels painfully slow because they go so fast and it feels like such a long wait til the next set of lessons. Definitely wish there was a way to increase the speed, even with simple slower/normal/faster settings, as it’s easy to alter the pace to slow down according to preferences, but not the other way.

But my perception and experience is definitely colored by the fact that I moved to Japan a few months ago with almost 0 Japanese (yeah I don’t even really watch anime) so I’m very motivated to learn as quickly as possible. Can’t say the immersion doesn’t help but I feel the motivation to not be illiterate is a much bigger factor. Like with anything in life, I believe effort and motivation are 99% of success!


I don’t think your brain capacity is the limiting factor. The thing is, you get better at mental tasks with practice and study. The more you review and do your lessons, the better your brain is going to get at doing them. The thing is, your mental state and how much energy you put into each lesson and review, are limited by the things going on in your life.

I used to think over a hundred reviews were a lot, but now, they’re not difficult, just time consuming. And sometimes I’ll stop a review session early when I feel a bit sluggish.

So far, around 9 days per level is what’s ended up being most comfortable for me long term. That’s doing all the lessons that come up within one or two days, usually one. Your mileage will vary.


I would say there is a limit on how much your brain can take in at once, but it depends on the person. One would also improve with practice like any other task. I met one person who had memorized entire books out of the Bible which was quite crazy to me, but he just started by doing single verses until he got good at it and then added more on as he improved his memory. I would say to just do whatever slightly stretches you so that you can improve.


As usual, @Leebo is correct. That being said, he didn’t really answer the question, so I will take his answer and apply it to the question.

Using Leebo’s method, I have found that I am good for about 20 new lessons that way. I have heard other people say they can do about 35. So you really need to find the number that works for you. I recommend starting out small and working your way up!

Best of luck :smiley: