Final answer:
The technique used to record electrical activity from the scalp is called Electroencephalography (EEG), which involves placing electrodes around the head to measure brainwaves. This data helps researchers study brain functions, especially sleep patterns, and diagnose sleep disorders.
Step-by-step explanation:
The technique used to record electrical activity from the scalp is called Electroencephalography (EEG). This method involves placing an array of electrodes around a person's head. The electrodes pick up the electrical signals produced by the brain and create a record, or printout, of the brain's electrical activity, also referred to as brainwaves. These measurements allow researchers to see both the frequency and amplitude of the brain's electrical activity with great precision. This kind of data is valuable, particularly for studying sleep patterns and diagnosing sleep disorders among other applications.
EEG is distinct from other brain imaging techniques that might use radiation or magnetic fields; it is specifically designed to measure the electrical activity in the brain. Despite the fast pace of the action potentials (electrical impulses in neurons), the EEG can precisely capture these signals, providing information on the overall brain activity rather than the specific location of activity inside the brain.