Final answer:
Recording the electrical activity of large groups of cortical neurons is done through Electroencephalography (EEG), which uses electrodes to measure brainwaves, while functional magnetic resonance imaging (fMRI) can map active brain areas in three dimensions.
Step-by-step explanation:
The study for the brain that involves recording the electrical activity of large groups of cortical neurons is known as Electroencephalography (EEG). This technique uses an array of electrodes placed around a person's head to measure the brain's electrical activity. The resulting data show the frequency and amplitude of the brainwaves with precision and is useful in various research areas, including the study of sleep disorders and other neurological conditions.Another method to measure brain activity is functional magnetic resonance imaging (fMRI), which provides a 3D map of the most active brain areas during specific tasks or conditions. Unlike traditional MRI, fMRI measures changes in tissue over time in relation to an experimental event, offering insights into the brain's functional areas and their interaction during cognitive processes.