Why is my EEG quality flickering in EmotivPRO?

EEG quality (EQ) in EmotivPRO helps users assess the quality of the brain signal from each sensor. It provides a real-time map that takes into account various factors such as movement, noise, signal amplitude, and other parameters that affect signal quality. It is normal for the EQ to flicker during recordings, and this article explains why and how to interpret it.

Understanding the EEG quality (EQ) 

The EQ map visually displays the quality of the EEG signal for each sensor on the headset. It helps users quickly gauge the raw signal quality without needing specialized training in EEG analysis. The flickering of the EQ is a common occurrence, as it reflects the changing conditions of the brain signal as you record.

Why does the EQ flicker?

It is totally normal for the EQ to flicker throughout the recording process. The signal quality may fluctuate due to various factors, such as:

• Movement: Any physical movement by the participant, such as shifting position or fidgeting, can cause signal disruptions.
• Noise and Artifacts: External interferences, such as electrical noise or muscle activity (EMG), can affect the clarity of the EEG signal.
• Signal Amplitude: The strength of the signal from the brain can vary, which also impacts the EQ display.

Please adjust each sensor individually, sit still and wait patiently for 3-5 seconds. If the signal flickers green at any point, it's likely the signal is good, but it is imperative to sit still to see if it maintains the green.

Low EEG quality (EQ) scores

• If the EQ map shows consistently low scores (orange or red), it usually indicates that one or more sensors are picking up significant noise or artifacts. This can be caused by poor sensor contact or insufficient prime fluid, gel, or saline solution. Make sure the sensors are properly positioned on the scalp, with no hair in the way, and that there is enough fluid for proper conductivity.
• If the EQ remains low despite adjustments, inspect the sensors for cleanliness or ensure they are securely in place.

Additional considerations

• Flickering is Normal: The EQ is not designed to stay steady throughout the entire session. Expect it to flicker, especially when the participant moves or if there is noise interference.
• Difference from CQ: Unlike the Cognitive Quality (CQ), the EQ is more sensitive and designed to quickly detect changes in the raw EEG signal. It is expected to fluctuate, so don’t be alarmed if it flickers frequently during the recording.

For more information on how to optimize EEG signal quality and understand the differences between CQ and EQ, refer to the EmotivPRO guides and support articles: View EQ article