Read EEG with confidence, from the first trace to the ICU.
Seven lessons, 27 patterns and a viewer where you change the montage, the filters and the gain yourself. Terminology follows ACNS 2021; every clinical statement carries its source.
Pattern of the day
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Learn EEG free, step by step
Montage is a free, evidence-based EEG course. It starts from zero, with what an electrode records and how a montage is built, and ends at the bedside in the ICU. You read short lessons, look at traces, change the montage and the filters yourself, then test what you have learned. No account, no ads.
The seven lessons
- 1. Foundations: signal, electrodes, montages, filtersWhere the signal comes from, the 10-20 system, how a montage changes what you see, and what filters can hide.
- 2. The normal EEG, awake and asleepPosterior dominant rhythm, beta, mu, lambda, drowsiness and the stages of sleep.
- 3. Artefacts: telling brain from everything elseEye, muscle, heart, electrode and environment. The questions that separate them from cerebral activity.
- 4. Epileptiform activity and seizuresWhat makes a discharge epileptiform, the syndrome signatures, activation procedures and the criteria for non-convulsive status.
- 5. Critical care EEGACNS terminology, periodic and rhythmic patterns, the ictal–interictal continuum, burst suppression and reactivity.
- 6. Focal lesions, coma, brain death and mimicsSlowing and what it localises, coma patterns, the technical standard for electrocerebral inactivity, functional seizures and benign variants.
- 7. Six casesSix bedside scenarios, each with its trace, the reading and the next step.
EEG pattern atlas
Every pattern has its own page with a trace, a description and its clinical meaning. See all 27 patterns.
- Posterior dominant rhythm
- Excess beta activity
- Mu rhythm
- Stage N2 sleep
- REM sleep
- SREDA
- Breach rhythm
- Wicket spikes
- Eye blink
- Muscle artefact
- Mains interference
- Electrode pop
- ECG artefact
- Focal polymorphic delta
- GRDA
- Diffuse slowing
- Focal sharp waves
- 3 Hz spike-and-wave
- Focal electrographic seizure
- BIRDs
- LPDs
- GPDs
- GPDs with triphasic morphology
- Periodic sharp wave complexes
- Burst suppression
- Alpha coma
- Electrocerebral inactivity
Questions
How do I start learning to read EEG?
Start with how a channel is built: electrodes, the 10-20 system and montages. Then learn the normal awake and sleep EEG before any abnormality, learn the artefacts, and only then the epileptiform and critical care patterns. Montage follows that order in seven short lessons, and lets you practise on traces as you go.
Is Montage free?
Yes. There are no ads, no subscription and no sign-up. Your progress is stored only on your own device.
Is the content evidence-based?
Terminology follows the American Clinical Neurophysiology Society 2021 critical care EEG terminology and the IFCN glossary. Each clinical statement links to its source: ACNS guidelines, the Salzburg criteria for non-convulsive status epilepticus, ILAE classifications, and the ERC–ESICM post-resuscitation guidelines among them.
Are the EEG traces real recordings?
No. They are simulated from a mathematical source model on the 19 electrodes of the 10-20 system, then derived into channels the way an EEG machine does it. That is why you can switch montage and filters and see phase reversals behave correctly. They are teaching illustrations, not patient data.
Who is it for?
Medical students, residents and fellows in neurology, clinical neurophysiology, critical care and emergency medicine, EEG technologists in training, and clinicians who want to understand the EEG reports they receive.
Can I use it to interpret a patient’s EEG?
No. Montage is an educational resource, not a medical device. Clinical EEG must be interpreted by a qualified clinician using the actual recording.
The course
EEG viewer
Traces are generated from a mathematical source model on the 19 electrodes of the 10-20 system and derived into channels as a real machine does. They are teaching illustrations, not patient recordings. Left-sided channels are blue, right-sided red, midline green.
Test yourself
Glossary
Sources
About Montage
Who it is for. Medical students, residents and fellows in neurology, critical care, emergency medicine and clinical neurophysiology, and anyone who has to make sense of an EEG report.
What it is not. A teaching resource, not a medical device. It does not interpret recordings and must not be used to make decisions about a patient. All traces are simulated.
Who made it. Dr Mohamed Najm, neurologist in neurocritical care and neurological emergencies, for The Tract · Independent Neurology Press. Content was drafted with AI assistance and checked against the primary sources listed above. Last reviewed November 2026. Corrections: contact@thetract.org.