An amplified recording of the waves of electrical activity that sweep across the brain's surface; measured by electrodes on the scalp.

• A. Cerebral Cortex
• B. EEG
• C. Parietal Lobes
• D. Occipital Lobes

Answer: (B)

EEG refers to an amplified recording of the brain’s electrical activity captured by scalp electrodes. It works by picking up the summed electrical signals produced by large groups of neurons, especially in the cortex, and turning them into wave patterns that reflect states like alertness, relaxation, or various cognitive processes. This method has excellent temporal precision, showing rapid changes in brain activity, though it doesn’t pinpoint exact where in the brain those signals come from as precisely as some imaging techniques. The other options describe brain structures or regions (the cerebral cortex, parietal lobes, occipital lobes) rather than the recording method itself, which is why EEG is the correct description.