Talking about something in a neurobiological way sends the message that this is a neurobiological issue. In this way, many fMRI papers serve to spread the idea that this is an issue that only neuroscience can solve and, therefore, create a demand for more fMRI studies. The authors of this paper are victims of this mentality, a widespread confusion about what neuroscience is for.
fMRI is a great way to approach neuroscientific questions. It’s a bad (and terribly expensive) way to do psychology. This study is about psychology, and should not have involved an MRI scanner.