During a microsleep, you are likely to:

During a micro-sleep, you are likely to have a blank stare, sudden shake of the body, head snapping and you are not able to recall a last minute.
The duration of micro-sleep are from 1 second to 30 second.
It can happen to anyone and at any time of the day. there are many reason of micro-sleep and it is said to be dangerous, especially when you are driving.