I wonder how much money they got for testing 14 people?
Anyways, cause for further study:
"Although these results are suggestive, further data will be required to assess the specific effects of these functional changes on behavior. Because numerous studies have already linked exposure to violent media with an increase in aggressive behavior [6], it seems reasonable to consider the effect observed here as a plausible component of a mechanism; however, it is important to note that in an otherwise pacific individual, it is very unlikely that these exposure-related changes are a sufficient catalyst for the emergence of criminal aggression. The strongest evidence for this claim is the fact that, although many individuals watch violent media, relatively few go on to commit criminally violent acts."