Loki was not presently paying attention to ....anything, really. His senses were dulled, or ignored. Even the light changing slowly outside he watched vacantly; it was seen without being registered. He did not hear anything, and if he were asked he would not be entirely sure what he was thinking, either.
He was simply... existing, at present. It was difficult to do more. It was simple to slip into stillness, like this; he had never realized inaction was this simple. While he had always been more still than Thor's constant motion and energy, he had always had his own brand of energy - a drive to do more, do better, to hold all the knowledge he possibly could, to twist circumstances to his advantage, or to the advantages of whoever he had decided to favor at the time...
...this was new, and he was fairly certain it was not something that would be considered good. But it felt ...better. It was easier, and he was tired.
The sound of his mother's voice drifting through the door slowly pulled him back towards proper awareness. He blinked, looked towards the door, frowning slightly; she was worried, that was clear - and she would very likely not be reassured if she saw him like this.
"I am," he responded, just loudly enough to carry. He considered altering the setting - placing himself at his desk, either by illusion or actually standing and moving there, or at the very least sitting upright with a book, here, if nothing else - but it seemed fairly pointless, at this point. She would know. She always did seem to know these things.