Can users automatically get an e-mail notice if their comments are answered?

Our colleagues like to use the comment function, but are not logging on to the Collaboration Hub very frequently. So if a process manager answers their comment and maybe has a question....nothing happens for a long time ;)

We always have to write an e-mail to the users and tell them that we have a question or that we updated the chart according to their comments. Which kind of defeats the purpose of a Collaboration Hub...is there a possibility that user get automatically notified via e-mail if their comment is answered?