These blackouts are characterized also by the ability to easily recall things that have occurred within the last 2 minutes, yet being unable to recall anything prior to this period. As such, a person experiencing an en bloc blackout may not appear to be doing so, as they can carry on conversations or even manage to accomplish difficult feats. It is difficult to determine the end of this type of blackout as sleep typically occurs before they end,[8] although it is possible for an en bloc blackout to end if the sufferer has stopped drinking in the meantime.