G. Alarimm said:
The sample size is much too small, the article does not mention a control, the "evidence" or rather "results" are trivial and are affected by FAR too many factors to point to a single thing, and no, you are indeed not a neuroscientist.
Actually the 8/20 vs 16/20 is enough samples to establish a difference with an alpha < .05, which is generally acceptable as a strong result. The control is the football playing group. This is better than a group that did "nothing", since then it could be blamed on plenty of other factors, like adrenaline. You're right about there being too many factors tho, a non-violent but equally engaging game, like say Portal vs HL2, would have made more sense.
My problem is more with her methodology. This was not a double-blind experiment, because based on this description I'd say it's likely she knew which students had done football vs videogames when she conducted the pencil-drop test. She should have someone else performing this test who didn't know.
Of course, I'm not going to address the heart-rate study, since that's not actually showing anything meaningful. Yes, they were primed so they were familiar with violence ahead of time, and we're surprised when they saw more. Big deal.