The Americans recently conducted a study: they Took three groups of students. One group asked to imagine ourselves - as they go to the polls. The other asked the first person, as they participate in the elections. The third control (and it not represented and did not even know what they are involved). So, in the first group, the turnout was 70%, second 3%, in the control and 20%.
From the point of view of elementary logic, all is absolutely natural. Those who imagine the first person that do something, actually do it (according to the same Sechenov, for the brain, between the real event and imaginary makes no difference). Therefore, if this action does not deliver the real pleasure, what sense to repeat?
From the point of view of skills all, just the opposite. Again, a classic experiment with basketball players: one group for a month really threw the ball into the ring, a second imagined (first person) that were thrown, third test. Now, in the second group the results of getting into the ring, when checked, was only slightly worse than the first, and considerably better than in the controls.
So really, it all depends on goals.