For the purposes of the above study 'impulsivity' was operationalized as follows:

> ignoring visual cues to stop as they repeatedly pressed the button.

I'm wondering whether the same 'impulsivity' (and active brain regions) would be found in controls who were similarly experiencing an intense emotional experience.

Without that data... Hard to know what to conclude from the study really...

If the findings aren't specific to borderlines (as opposed to subjects with phobia, delusions, or normal controls who are similarly triggered into an intense emotional response) then they haven't found out anything about borderline personality. Instead, they would have found something about NORMAL or TYPICAL neurological processing and behavioral response to intense emotional experiences.