But I digress. You know how, sometimes, right before you fall sleep, you’ll have those weird hallucination-type things, and it’s somewhere in between waking and sleeping and feels surprisingly real? If you don’t know what I’m talking about, then this post may not make any sense to you.

For the rest of you, check out this research where people actually studied those hallucinatory moments right before sleep. By the way, being a participant in this study seems like it was equal parts awesome and annoying.

Who doesn’t like Tetris? (No one.) For this study, in which the participants were almost certainly financially compensated, researchers asked test subjects to play Tetris for two hours every morning for three consecutive days — sign me up! Here is a diagram, because this is the awesome part of the study:

Being woken up 15 seconds after falling asleep.

Then, the researchers told the subjects to take a nap in the afternoon (this study just keeps getting better). Here’s the catch: subjects were woken up either 15, 45, 75, 120 or 180 seconds after falling asleep. The subjects, after mumbling expletives to the scientists, then reported their “mental content” to three judges.

In what may or may not be a surprising result, 10% of the subjects (48 out of 485 people) reported experiencing exact replicas of the sights and sounds of Tetris. This was in contrast to two control groups: one in which the subjects played no games (sad face) and only 1 person in 107 reported Tetris-related hallucinations (ummm…Tetris fanatic much?); in the second group, participants played Tetris after the nap (still a sweet deal), and only 3 out of 112 of those guys pre-dreamed about Tetris (oh, the anticipation!).

So the key takeaway here is simply this: Don’t watch Nightmare on Elm Street films right before taking a nap. Not only because Freddy Krueger will enter your dreams and kill you (duh), but because you might vividly hallucinate about him right before you fall sleep. And no one wants that.

Stay nerdy

Kusse C, Shaffii-LE Bourdiec A, Schrouff J, Matarazzo L, & Maquet P (2012). Experience-dependent induction of hypnagogic images during daytime naps: a combined behavioural and EEG study. Journal of sleep research, 21 (1), 10-20 PMID: 21848802