What does an EEG record?

An EEG, or electroencephalogram, specifically records the electrical activity of brain cells, known as neurons. This technique involves placing electrodes on the scalp to detect the tiny electrical charges that result from the activity of brain cells communicating with each other. The resulting data provides vital information about the brain's overall function, allowing for the assessment of various neurological conditions, monitoring brain health, and even investigating sleep patterns. The accuracy and utility of EEG in capturing real-time brain activity make it a fundamental tool in neuroscience and clinical psychology.

The other options pertain to different physiological measurements: the chemical composition of blood is assessed through blood tests, muscle movement patterns are monitored using electromyography (EMG), and the heart's electrical activity is recorded using an electrocardiogram (ECG). Each of these methods serves distinct purposes and utilizes different techniques, underscoring the unique role of EEG in understanding brain dynamics.