Week 1 Nap Lab: Finding your dip

The first Nap Lab — you learn the two instruments this course measures everything with, and use them to locate your own afternoon trough

22 February 2027

Nobody naps this week. Before you can tell whether a nap did anything, you need two measurements you trust and a rough idea of your own baseline — and those take a session to learn properly rather than ten rushed minutes at the start of next week’s lab, which is when you will need them.

Before the lab#

• Arrive having noticed when your alertness drops, without having read about it. A guess you formed yourself is more useful here than a correct answer you borrowed, because we are about to test it.
• Keep the day ordinary. Do not sleep in, do not skip caffeine, do not skip lunch. Week 3 and week 4 touch those variables deliberately and one at a time.

In the lab#

The two instruments, forty minutes. You will use both of these every week for the rest of the semester, so we spend real time on them now.

1. The Karolinska Sleepiness Scale. One number, 1 (“extremely alert”) to 9 (“very sleepy, fighting sleep”). It looks too crude to be worth anything. It holds up against far more expensive measures, and we will look at why.
2. A simple reaction-time task. Ten trials, and you take the median, not the mean. One distracted trial should not be allowed to speak for the set — this is the most common way a week’s data quietly becomes useless.

Locating the dip, thirty minutes. In pairs, you will reconstruct yesterday hour by hour and mark where each of you thinks the trough fell. Then we pool the estimates on the board. Two things usually show up: the estimates cluster far more tightly than the room expects, and a handful of people sit well outside the cluster. Both of those are results.

What the Nap Log wants, twenty minutes. We walk through the recording format before you are committed to it. The Nap Log runs for two weeks and starts in earnest after next week’s lab, and the most common way it goes wrong is a format decided in week 2 and abandoned by week 4.

Afterwards#

You leave with a baseline, a recording format, and an estimate of your own trough. Write the estimate down somewhere you will not edit it later. In week 4 you will find out whether it was right, and a prediction you can no longer quietly revise is worth considerably more than one you can.