1) Navigate to Dashboards | Administration | Users & Security
2) You can also control how often each individual dashboard refreshes (see below).
How to configure the refresh of a dashboard:
Open the dashboard | expand the Actions Panel (right side) | click General Tab | Properties | Edit Basic Properties | select "Automatically Refresh page every ____"
Note: If you have the Admin Console open to a dashboard that "refreshes" before the console session timeout period, you will not be 'timed out' because of the refresh makes it seem there is activity in the session.