Watching attentively - monitor.
Observant, scrutinize, focused, astute.
Distracted or inattentive.
Asleep, not paying attention, lazy
The word alert can be an adjective, which describes someone who is aware of his or her surroundings and is paying attention to them. The guard was alert. Alert can also be a verb; if you alert someone to some situation you are directing their attention to it. I alerted the policeman to the robbery in progress.
Beating.
crystalline
Hearkening means paying attention. Hearkening to the warning will save you trouble in the end.
players that are not paying attention recieve admonishing quetions from their coach
Uncomfortable around others, fidgeting/not paying attention/'non caring' voice.
word count
"Wasn't that a boring lesson?" "I don't know - I wasn't paying attention."
Insanity?
A synonym for "distraction" is disturbance. There is no antonym. Please see the related link below.