Hi, well this is just from personal experience so ymmv, but I've been playing the game off and on for the past two years and am convinced of positive effects.
I do know that, beforehand, I had never been able to study for protracted periods of time and enjoy the experience - for me, studying had always been a fight against intellectual and physical restlessness (=restless legs, itching, shifting about on my seat). DnB seems not only to permit me to sit down and focus for long periods, it actually makes me want to study - I feel compelled to learn and get annoyed if prevented from doing so. And when I do study, I can now put in serious hours (typically three or four chunks of 2 1/2hr blocks).
I'm sure that this sounds somewhat implausible, but there have been many occasions on which I have been overwhelmed yet again by the determined demons of dilettantism and distraction only to remember what I had let slip from my routine.
I would not be so sure of positive effects if, after having trained for a few days, I had suffered an exacerbation of symptoms, but this has not occurred.
The simplest explanation that I can think of is that it is the only activity that forces me to use the entirety of my attention, encouraging me to eliminate distracting thoughts (as in meditation?) whilst also providing a tightly-defined focal point (the stimuli in space and time) and overarching purpose (to find order (as organizing my impressions helps me remember)). Perhaps this is where my feelings of increased purposefulness come from: the game trains me generally to enjoy drawing connections, and I begin to want to organize the world around me.
I guess another question I'd like to ask is whether you enjoy dual-n-back. I've tried it a couple of times and consistently disliked it precisely as I would dislike a cold shower.
Now that I think of it, there are many mental activities that I dislike precisely that way. (Or, at least, there used to be many; now there are fewer.) One of them is the Gunnery puzzle in Puzzle Pirates. To try to extract a general trend here, I tend to dislike things that require me to react quickly. I used to loathe such things, along with a host of other things: asymmetry, dis...
I recently had occasion to review some of the akrasia tricks I've found on Less Wrong, and it occurred to me that there's probably quite a lot of others who've tried them as well. Perhaps it's a good idea to organize the experiences of a couple dozen procrastinating rationalists?
Therefore, I'll aggregate any such data you provide in the comments, according to the following scheme:
Every so often, I'll combine all the data back into the main post, listing average scores, sample size and common effects for each technique. Ready?
Here's the list of specific akrasia tactics I've found around LW (and also in outside links from here); again, if I'm missing one, let me know and I'll add it. Special thanks to Vladimir Golovin for the Share Your Anti-Akrasia Tricks post.
Without further ado, here are the results so far as I've recorded them, with average score, number of reviews, standard deviation and recurring comments.
3 or More Reviews:
Collaboration with Others: Average +7.7 (3 reviews) (SD 0.6)
No Multitasking: Average +6.0 (3 reviews) (SD 2.0); note variants
P.J. Eby's Motivation Trilogy: Average +5.8 (6 reviews) (SD 3.3)
Monoidealism: Average +8.0 (3 reviews) (SD 2.0)
"Just Do It": Average +4 (2 reviews) (SD 4.2)
Irresistible Instant Motivation: +3 (1 review)
Getting Things Done: Average +4.9 (7 reviews) (SD 2.6)
Regular Exercise: Average +4.4 (5 reviews) (SD 2.3)
Cripple your Internet: Average +4.2 (11 reviews) (SD 3.0)
LeechBlock: Average +5.4 (5 reviews) (SD 2.9); basically everyone who's tried has found it helpful.
PageAddict: +3 (1 review)
Freedom (Mac)
Melatonin: Average +4.0 (5 reviews) (SD 5.4); works well for some, others feel groggy the next day; might help to vary the dosage
Execute by Default: Average +3.7 (7 reviews) (SD 2.4); all sorts of variants; universally helpful, not typically a life-changer.
Pomodoro Technique: Average +3.3 (3 reviews) (SD 4.2); mathemajician suggests a 45-minute variant
Being Watched: Average +3.2 (6 reviews) (SD 4.1); variations like co-working seem more effective; see "collaboration" below
Utility Function Experiment: Average +2.8 (4 reviews) (SD 2.8)
Meditation: Average +2.8 (5 reviews) (SD 2.8)
Modafinil and Equivalents: Average -0.8 (5 reviews) (SD 8.5); fantastic for some, terrible for others. Seriously, look at that standard deviation!
Structured Procrastination: Average -1.0 (3 reviews) (SD 4.4); polarized opinion
Resolutions (Applied Picoeconomics): Average -3.2 (5 reviews) (SD 3.3); easy to fail & get even more demotivated
1 or 2 Reviews:
Dual n-back: Average +6.5 (2 reviews) (SD 2.1)
Think It, Do It: Average +6 (2 reviews) (SD 1.4)
Self-Affirmation: Average +4 (2 reviews) (SD 2.8)
Create Trivial Inconveniences to Procrastination
Close the Dang Browser: Average +3.5 (2 reviews) (SD 3.5)
Get More Sleep: Average +3 (2 reviews) (SD 1.4)
Every Other Day Off: Average +0.5 (2 reviews) (SD 0.7)
Strict Scheduling: Average -9 (2 reviews) (SD 1.4)
Elimination (80/20 Rule): +8 (1 review)
Methylphenidate: +8 (1 review)
Begin Now: +8 (1 review)
Learning to Say No: +8 (1 review)
Caffeine Nap: +8 (1 review)
Write While Doing: +8 (1 review)
Leave Some Tasty Bits: +7 (1 review)
Preserve the Mental State: +6 (1 review)
Acedia and Me: +5 (1 review)
Third Person Perspective: +5 (1 review)
Watching Others: +5 (1 review)
Multiple Selves Theory: +5 (1 review)
Getting Back to the Music: +5 (1 review)
Remove Trivial Inconveniences: +4 (1 review)
Accountability: +2 (1 review)
Scheduling Aggressively...: +2 (1 review)
Autofocus: 0 (1 review)
Take Every Other 20 to 40 Minutes Off: -4 (1 review)
Not Yet Reviewed:
Fire and Motion
Stare at the Wall
Kibotzer
Thanks for your data!
EDIT: People seem to enjoy throwing really low scores out there for things that just didn't work, had some negative side effects and annoyed them. I added "-10 if it nearly killed you" to give a sense of perspective on this bounded scale... although, looking at the comments, it looks like the -10 and -8 were pretty much justified after all. Anyway, here's your anchor for the negative side!