In the context of driving, what does the term 'micro-sleep' refer to?

The term 'micro-sleep' refers to a brief lapse in attention where a driver may temporarily lose focus or responsiveness to the driving environment. This can occur without the driver being fully aware, often lasting just a few seconds. During this time, the brain experiences a momentary switch to a sleep-like state, which can happen even when a person is awake and trying to stay alert.

This phenomenon is particularly dangerous for drivers because it can lead to a lack of awareness of surrounding hazards, increased reaction times, and ultimately, a higher risk of accidents. It's paramount for drivers to recognize the signs of fatigue and to take corrective actions, such as pulling over to rest or seeking help, rather than attempting to drive through these lapses.

The other options describe different states related to sleep but do not accurately capture the essence of what a micro-sleep entails—specifically the fleeting nature of the lapse in attention while still being awake.