If you would like to change your notification preferences you will navigate to the "Edit Profile" screen shown below.
To change your notification preferences click "Notification Preferences" in the menu to the right.
Here you can edit your general notification preferences, this section centers around when the types of notifications you receive (email or popup) when people engage with you, you earn a new status or badge, etc.
You can also change your Discussions and Comments notification preferences for specific Categories.