Dual N-Back

Apparently, there might exist a game which could improve fluid intelligence:
Serious source?: http://ns.umich.edu/new/releases/8420
Not so serious source: http://www.bulletproofexec.com/how-to-add-2-75-iq-points-per-hour-of-training/

and the site to get it: http://brainworkshop.sourceforge.net/

Basically, every 3 seconds you hear a sound, and a square light up. You need to say if same square lighted up N times ago, and same for the sound.

At beginning u first try just 1 step back (which is fairly easy), but as you get better you increase the N back, and it gets hard fast.

Any idea if this really does work?

An in-depth overview and FAQ: http://www.gwern.net/DNB%20FAQ

From his personal conclusions, which I mostly agree with:

To those whose time is limited: you may wish to stop reading here. If you seek to improve your life, and want the greatest "bang for the buck", you are well-advised to look elsewhere. Meditation, for example, is easier, faster, and ultra-portable. Typing training will directly improve your facility with a computer, a valuable skill for this modern world. Spaced repetition memorization techniques offer unparalleled advantages to students. Nootropics are the epitome of ease (just swallow!), and their effects are much more easily assessed - one can even run double-blind experiments on oneself, impossible with dual N-back. Other supplements like melatonin can deliver benefits incommensurable with DNB - what is the cognitive value of another number in working memory thanks to DNB compared to a good night’s sleep thanks to melatonin? Modest changes to one’s diet and environs can fundamentally improve one’s well-being. Even basic training in reading, with the crudest tachistoscope techniques, can pay large dividends if one is below a basic level of reading like 200WPM & still subvocalizing. And all of these can start paying off immediately. DNB, on the other hand, requires a minimum of 15 hours before one can expect genuine somatic improvements. The task itself is unproven - the Jaeggi studies are suggestive, not definitive (and there are contrary results). Programs for DNB training rely essentially on guesswork as they explore the large design-space; there are no data on what features are essential, what sort of presentation optimal, or even how long or when to train for. The task itself is unenjoyable. It can be wearying, difficult & embarrassing. It can be one too many daily tasks, a straw which breaks the camel’s back, and a distraction from whatever activity has the greatest marginal utility for one and one ought to be doing instead.

Actually improving working memory would be huge. I really hope it gets studied more rigorously. The big question for any supposed intelligence-increasing exercise is whether training on the n-back task actually creates any cross-domain improvement. Dual n-back IS unpleasant to practice, and even if you get better at it there's currently quite little evidence you get better at anything else. I think spaced repetition in particular is a much more useful learning tool that most people will get more out of.