Which neuroimaging technique evaluates electrical activity within the cortex?

The correct choice is the Electroencephalogram (EEG), which is a neuroimaging technique specifically designed to evaluate the electrical activity produced by neuronal activity within the cortex. EEG works by placing electrodes on the scalp to detect the electrical signals that neurons generate during various brain activities, such as thinking, responding to stimuli, and sleeping. This technique provides real-time insights into brain function, capturing rapid changes in electrical activity which is essential for understanding both normal and abnormal brain states.

Functional MRI, while also a neuroimaging technique, measures changes in blood flow and oxygenation rather than directly capturing electrical activity. It is often used to infer brain activity by looking at metabolic responses associated with neuronal firing, but it does not provide direct measurements of electrical signals.

Magnetoencephalography (MEG) detects the magnetic fields generated by the electrical activity of neurons. Although it is closely related to EEG and provides information about brain activity, it is not the technique primarily designed for directly measuring electrical activity on the scalp itself.

Positron Emission Tomography (PET) assesses metabolic processes in the body by tracking radioactive substances, providing insights mostly into blood flow and metabolic functions in the brain rather than direct electrical activity.

Thus, while all options relate