Battery guide
Sleep and Fatigue Battery guide
Four tests of alertness for sleep and fatigue research: vigilance lapses, reaction speed, sustained attention and visual search.
- Guide version
- 1.2.0
- Battery version
- 1.0.0
What it measures
Who it is for: Sleep and fatigue research.
It measures Vigilance and lapses of attention, Psychomotor speed, Sustained attention and response control and Visual search efficiency.
Attention: Keeping attention on a task and picking out what matters.
Processing speed: How quickly people take in information and respond.
Scores describe how a person performs on these tasks. Research use only.
Tests in order
The tests run in this order. A study started from the battery keeps the order and the settings.
1. Psychomotor Vigilance Task. Measures sustained attention by requiring rapid responses to infrequent visual targets over variable waiting intervals.
2. Simple Reaction Time. Measures basic processing speed by asking participants to respond as quickly as possible when a stimulus appears on screen.
3. Sustained Attention to Response. Measures sustained attention and response inhibition. Digits 1 to 9 appear at a fixed pace, and participants press for every digit except 3, which appears on about 11% of trials.
4. Visual Search Test.
| Order | Test | Domain | Time |
|---|---|---|---|
| 1 | Psychomotor Vigilance Task | Attention | 4 to 6 minutes |
| 2 | Simple Reaction Time | Processing speed | 2 to 3 minutes |
| 3 | Sustained Attention to Response | Attention | 5 to 7 minutes |
| 4 | Visual Search Test | Attention | 5 to 7 minutes |
Time and devices
Allow about 23 minutes for the whole battery. The table gives each test's time.
The battery has timed tests. Participants need a desktop or laptop with a mouse or trackpad, and the timed tests run in full screen. Tablets and phones cannot run it.
On a desktop or laptop the screen must be at least 1024 by 700 pixels.
Participants need Chrome, Edge, Firefox or Safari.
| Test | Timing | Devices |
|---|---|---|
| Psychomotor Vigilance Task | Timed | Desktop or laptop |
| Simple Reaction Time | Timed | Desktop or laptop |
| Sustained Attention to Response | Timed | Desktop or laptop |
| Visual Search Test | Timed | Desktop or laptop |
Languages
Runs in all eight participant languages.
How to give it
Start a study from the battery in the app. The tests, their order and their settings are already set and stay fixed. If you change, reorder or customize a test, the study becomes a custom study and no longer carries the battery.
Each test opens with its instructions. Participants see these:
Psychomotor Vigilance Task: Keep your eyes on the screen and press the SPACEBAR as soon as the stimulus appears. Respond quickly but avoid anticipatory presses.
Simple Reaction Time: Press the spacebar as quickly as you can when you see the target appear on screen.
Sustained Attention to Response: Press SPACEBAR for every digit except 3. Do not press when you see a 3.
Visual Search Test: Decide whether the target is present in each display. Displays vary in search type and number of items.
| Step | Before you invite participants |
|---|---|
| 1 | Decide when in the day participants take the battery, and keep that time for every session. |
| 2 | Record hours slept and time awake before each session if your protocol needs them. |
| 3 | Ask participants to sit somewhere they will not be interrupted for about 25 minutes. |
| 4 | Pilot the battery yourself on a desktop or laptop. |
How each test is scored
The server scores each test when the participant finishes it. The primary score is the one the app compares with a norm. The other scores are reported with it.
Every result records its scoring version. For this battery they are Psychomotor Vigilance Task 1.0.1, Simple Reaction Time 1.0.0, Sustained Attention to Response 2.0.0 and Visual Search Test 1.0.0.
| Test | Score | What it is | Better |
|---|---|---|---|
| Psychomotor Vigilance Task | Mean Reaction Time (ms, primary) | Average valid response latency across scored trials. | Lower is better |
| Psychomotor Vigilance Task | Median Reaction Time (ms) | Median response latency, less influenced by outlier lapses. | Lower is better |
| Psychomotor Vigilance Task | RT Standard Deviation (ms) | Intraindividual variability of response speed. | Lower is better |
| Psychomotor Vigilance Task | Lapses | Missed responses or responses slower than the lapse threshold set for the study (500 ms standard). | Lower is better |
| Psychomotor Vigilance Task | False Starts | Anticipatory responses under 100ms. | Lower is better |
| Psychomotor Vigilance Task | Response Rate (proportion) | Proportion of trials with any response before timeout. | Higher is better |
| Simple Reaction Time | Mean Reaction Time (ms, primary) | Average reaction time across valid trials, excluding anticipatory responses (<100ms). | Lower is better |
| Simple Reaction Time | Median Reaction Time (ms) | Median reaction time, more robust to outliers than the mean. Preferred when the RT distribution is skewed. | Lower is better |
| Simple Reaction Time | RT Standard Deviation (ms) | Standard deviation of reaction times. Reflects response consistency (intraindividual variability). Elevated IIV is a biomarker for cognitive decline. | Lower is better |
| Simple Reaction Time | Minimum RT (ms) | Informational | |
| Simple Reaction Time | Maximum RT (ms) | Slowest response recorded. May indicate lapses in attention. | Informational |
| Simple Reaction Time | Accuracy (proportion) | Proportion of trials with a valid response. Expected near ceiling for healthy participants. | Higher is better |
| Sustained Attention to Response | Commission Errors (primary) | Presses on a 3, where the response should be withheld. | Lower is better |
| Sustained Attention to Response | Commission Error Rate (proportion) | Commission errors divided by the number of 3s shown. | Lower is better |
| Sustained Attention to Response | Omission Errors | Digits other than 3 with no press. | Lower is better |
| Sustained Attention to Response | Go RT (ms) | Mean response time on digits other than 3, from digit onset. Presses under 100 ms are left out. | Informational |
| Sustained Attention to Response | RT Variability | Coefficient of variation of go response times (standard deviation divided by mean). | Lower is more consistent |
| Sustained Attention to Response | Post-Error Slowing (ms) | Response time after a commission error minus the mean of the responses four trials before and after it. | Informational |
| Sustained Attention to Response | Accuracy (proportion) | Share of trials with a press on digits other than 3 and no press on 3. | Higher is better |
| Sustained Attention to Response | Thought Probes Answered | With the thought probe setting on: test probes answered. | Informational |
| Sustained Attention to Response | On the Task (proportion) | With the thought probe setting on: share of probes answered with attention on the task, the digits and the presses. | Informational; compare groups and conditions |
| Sustained Attention to Response | Thoughts About the Task (proportion) | With the thought probe setting on: share answered with attention on how the task was going or how long it would last. | Informational |
| Sustained Attention to Response | Surroundings or Body (proportion) | With the thought probe setting on: share answered with attention on something around the participant or in the body. | Informational |
| Sustained Attention to Response | Mind Wandering (proportion) | With the thought probe setting on: share answered with attention on thoughts unrelated to the task. | Informational; compare groups and conditions |
| Sustained Attention to Response | Mind Blank (proportion) | With the thought probe setting on: share answered with attention nowhere, the mind blank. | Informational |
| Sustained Attention to Response | Off the Task (proportion) | With the thought probe setting on: share answered with attention away from the task (surroundings or body, unrelated thoughts, or nowhere). | Informational; compare groups and conditions |
| Sustained Attention to Response | RT Variability Before On-Task Answers | With the thought probe setting on: coefficient of variation of go response times in the 8 trials before each probe answered on the task, averaged over those probes; a window needs 5 go responses at or after 100 ms. | Informational; compare with the off-task value |
| Sustained Attention to Response | RT Variability Before Off-Task Answers | With the thought probe setting on: the same before probes answered away from the task. | Informational; Bastian and Sackur (2013) found it higher than before on-task answers |
| Sustained Attention to Response | 3s Pressed Before On-Task Answers (proportion) | With the thought probe setting on: share of the 3s in the 8 trials before probes answered on the task that were pressed. | Informational; compare with the off-task value |
| Sustained Attention to Response | 3s Pressed Before Off-Task Answers (proportion) | With the thought probe setting on: share of the 3s in the 8 trials before probes answered away from the task that were pressed. | Informational |
| Visual Search Test | Overall Accuracy (proportion) | Proportion of scored visual-search trials answered correctly. | Higher is better |
| Visual Search Test | Target-Present Accuracy (proportion) | Accuracy when the target was present. | Higher is better |
| Visual Search Test | Target-Absent Accuracy (proportion) | Accuracy when the target was absent. | Higher is better |
| Visual Search Test | Feature Search Slope (ms/item) | RT-by-set-size slope for feature-search trials. | Lower is better |
| Visual Search Test | Conjunction Search Slope (ms/item, primary) | RT-by-set-size slope for conjunction-search trials. | Lower is better |
| Visual Search Test | Target-Absent Cost (ms) | Mean correct target-absent RT minus mean correct target-present RT. | Lower is better when accuracy is adequate |
Session quality rules
The app checks every session when it scores it and records one of four states.
An Invalid session stays in the study's results, labelled with its reason, and does not count toward norms.
A session can carry warnings and still be valid. The results list the warnings next to the scores.
| State | What it means |
|---|---|
| Norm-ready | The session passed every check and a norm exists for it, so the app can show a percentile. |
| Raw-only | The scores are usable, but the app shows no percentile. Typical reasons are no norm for the test, changed settings, or a warning that makes a comparison unfair, such as a restart or a screen too short for the display. |
| Invalid technical | The setup broke the timing or the task. Examples are leaving full screen, a browser tab that lost focus during a timed test, and long pauses. |
| Invalid behavioral | The responses suggest the task was not done as asked. Examples are a failed attention check, repeated switching away from the task, and accuracy at or below chance on a choice task. |
Published norms used
No published norm is used for any test in this battery.
ConductCognition also builds norms from its own participants. An age band of a test uses them once it holds at least 50 valid sessions on the same device and input type, run with standard settings and scored with the current scoring version. Sessions from paying customers' studies and from clinical or patient samples do not count.
A report shows a percentile only when the app has stored one for that session. Otherwise it shows the raw scores.
Every reference group covers ages 18 and over. No reference group covers a participant under 18, so their report shows raw scores only, and their sessions do not count toward norms.
How to cite
ConductScience, Inc. Sleep and Fatigue Battery guide, version 1.2.0. ConductCognition. https://conductcognition.com/batteries/sleep-fatigue/guide
Cite the guide version you used. Name the battery version (1.0.0) and the scoring versions listed in this guide.