The power of ignoring
washingtonpost.com
washingtonpost.com
"Worse is better" makes it possible: relax the requirements, get the job done.
If you try to guarantee that you don't think of a polar bear, that is oxymoronic, because to concentrate on not thinking of a polar bear, you have to continuously hold a polar bear symbol in your consciousness, which means you're doing nothing but thinking of a polar bear.
There is no difference between looking for items which match some criteria, and looking for items which do not.
The classification type looks like a big red herring.
It is a problem of exhaustively partitioning a set of items into two classes. "Retain" and "reject" are just arbitrary labels for these classes, which might as well be "A" and "B" or whatever else.
Whether it is easier to calculate class A or B depends entirely on the statistical properties of the specific input relative to the complexity of the criteria for determining class membership in A versus B.
For instance, suppose membership in A means satisfying the correct attribute values in fifty different properties. Now suppose that most of the objects in the input set satisfy the test in 49 properties, failing only in one. Only a few objects satisfy all 50 properties with the correct attributes. Then the task will be hard, and it will be equally hard whether the focus is to identify B's or A's, because either way it is a separation of A's from B's.
If you give me a jar of beans, where all are white, but about six or seven are black, I can easily give you all the white ones, or all the black ones. Either way I pick out the black ones. Then I have them separated and I just give you whichever set you asked for. If the mix is 50/50, it's a lot more work, whether you ask for black or white.
The study suggests that the ability to pay attention to
something is driven by inhibition.
Inhibition sounds like the opposite of openness, and openness is considered vitally important to being a good programmer according to http://arstechnica.com/science/2015/11/programmers-are-a-tin...
In the human brain, neurons fire in response to various stimuli (but generally not in response to the lack of stimuli). Consequently, to moderate all the neural activity and prevent you from going spastic all the time, part of the brain modulates/attenuates the neural response to given stimuli. Effectively, this part of the brain inhibits your responses/actions. This is, for example, why alcohol makes people do stupid things--it inhibits the inhibition units in their brain, so the part of the brain that says "this is a bad idea" never speaks up.
As applied to concentration, inhibition is your brain tamping down on the distracting signals so that you can focus on whatever it is you're trying to focus on.
[Edit: excessive inhibition is also thought to play a role in Parkinson's disease. There, the problem is that the inhibition units function too strongly in response to self-initiated actions. This limits the victim's ability to initiate actions such as walking. Responsive action is not as badly effected by Parkinson's, so to walk many victims bounce a cane off the front of their leg to set up an external stimuli for their body to respond to.]
This Wikipedia page can provide a better overview/launching pad for self-directed research: https://en.wikipedia.org/wiki/Cognitive_inhibition