Categories: About The EEG Tech Career

Brain Meets Technology: What Makes EEG Electrodes Tick?

EEG technology can look like wires and waveforms—but behind it all is the incredible precision of electrode design and placement. Here’s how these tiny tools unlock the secrets of the brain.

Interested in how technology and neuroscience come together? Learn how EEGs and neurodiagnostic tools help capture brain activity in real time—and what it means for your future in the field.

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Electroencephalography (EEG) is one of the most powerful tools in modern neurodiagnostics. It records the brain’s electrical activity through small, precisely placed electrodes attached to the scalp. But while the wavy lines on the screen get most of the attention, it’s the electrodes—and the technologists who place them—that make everything possible.

Each EEG electrode is designed with precision in mind. The materials, size, contact gel, and even the wire length all affect how well brain activity is captured. For students entering the field, understanding how electrodes work is foundational—not just for accurate results, but also for patient safety and comfort.

🔍 Insights

The EEG doesn’t record the brain directly—it records patterns created by electrical activity near the scalp. That’s why proper electrode placement is critical to catching the right signals.

What EEG Electrodes Are Made Of

🧲 Materials That Conduct, Not Interfere

EEG electrodes are typically made of silver-silver chloride (Ag/AgCl), gold, or stainless steel. These materials are chosen for their ability to conduct small electrical signals without creating interference or noise. Each has benefits: gold is long-lasting, Ag/AgCl offers excellent signal stability, and stainless steel is durable and affordable.

🧴 The Role of Gel and Paste

To ensure a clean electrical connection between the electrode and the skin, a conductive paste or gel is applied. Without this, skin oils or hair can block the signals, resulting in a weak or noisy readout. The right amount and evenness of gel application is part of the technologist’s skill set.

📍 Placement: The 10-20 System

EEG technologists use a globally standardized method known as the 10-20 system to place electrodes on the scalp. These measurements are based on the size of the head and specific anatomical landmarks like the nose bridge and the inion (bony bump at the back of the skull). Precision is non-negotiable—just a centimeter off can distort results.

🧠 Interpreting the Results

Once electrodes are in place and recording begins, the data collected is only as good as the quality of the connection. A misplaced or loose electrode can cause artifacts—unwanted wave patterns—that can mimic or hide real brain activity. It’s one reason why technologists must constantly monitor and adjust during a scan.

Core Concepts END Technologists Learn About EEG Electrodes

Types of EEG electrodes and when to use each (cup, disc, needle)
How to measure and mark the scalp using the 10-20 system
Proper skin preparation and use of conductive media
Signal troubleshooting and artifact detection
Sterilization and patient safety practices in neurodiagnostics

To most people, EEGs look like a tangle of wires and a blinking screen. But to trained electroneurodiagnostic technologists, they’re stories—electrical snapshots of thought, rest, and reflex. It all starts with the electrodes, and the care that goes into placing each one.