A researcher wants to study the brain's immediate reaction to a sudden, unexpected sound. The primary goal is to determine the exact moment the brain's response begins, with millisecond precision. The researcher is less concerned with identifying the specific, deep brain structure that is reacting. Why would a technique that measures the brain's overall electrical activity from the scalp be the most appropriate choice for this study?

A researcher is studying the brain's response to a sudden, unexpected sound. Their primary goal is to determine the precise timing of the brain's electrical reaction, within milliseconds of the sound occurring. They are less concerned with identifying the exact anatomical source of the reaction. Why is a technique that measures the brain's general electrical activity from the scalp a suitable choice for this specific research goal?