Which device monitors and records waves of electrical activity in the brain using scalp electrodes?

Which device monitors and records waves of electrical activity in the brain using scalp electrodes?

• A. PET Scan
• B. CT Scan
• C. Electroencephalogram (EEG)
• D. MRI

Answer: (C)

The device that monitors and records waves of electrical activity in the brain using scalp electrodes works by picking up the brain’s synchronized electrical signals from the cortex. An electroencephalogram records these electrical potentials through electrodes placed on the scalp, producing waveforms that reflect different states of brain activity—like wakefulness, sleep stages, or seizure activity. It has excellent temporal resolution, capturing changes on a millisecond scale, which is ideal for tracking rapid brain dynamics. Other imaging methods serve different purposes. A PET scan tracks metabolic processes with a radioactive tracer to show which brain areas are active, but it doesn’t measure electrical waves directly. A CT scan images the brain’s structure using X-rays, giving anatomy rather than electrical activity. An MRI primarily images soft tissue structure and, in functional MRI, infers activity through blood flow rather than recording electrical signals from the scalp. Therefore, only the electroencephalogram uses scalp electrodes to monitor and record the brain’s electrical activity.

The device that monitors and records waves of electrical activity in the brain using scalp electrodes works by picking up the brain’s synchronized electrical signals from the cortex. An electroencephalogram records these electrical potentials through electrodes placed on the scalp, producing waveforms that reflect different states of brain activity—like wakefulness, sleep stages, or seizure activity. It has excellent temporal resolution, capturing changes on a millisecond scale, which is ideal for tracking rapid brain dynamics.

Other imaging methods serve different purposes. A PET scan tracks metabolic processes with a radioactive tracer to show which brain areas are active, but it doesn’t measure electrical waves directly. A CT scan images the brain’s structure using X-rays, giving anatomy rather than electrical activity. An MRI primarily images soft tissue structure and, in functional MRI, infers activity through blood flow rather than recording electrical signals from the scalp. Therefore, only the electroencephalogram uses scalp electrodes to monitor and record the brain’s electrical activity.