Final answer:
Bilateral synchronous high amplitude spike and slow wave activity refers to delta waves, which have the lowest frequency and highest amplitude, occurring in deep, slow-wave sleep (NREM stage 3 sleep).
Step-by-step explanation:
Bilateral synchronous high amplitude spike and slow wave activity is characteristic of delta waves. These are the brain waves with the lowest frequency and highest amplitude, typically seen in deep, slow-wave sleep (NREM stage 3 sleep). These delta waves are less than 3 Hz in frequency and are distinct from theta waves (4-7 Hz, moderate amplitude), alpha waves (8-12 Hz, lower amplitude), and beta waves (13-30 Hz, very low amplitude) which are associated with other stages of wakefulness and sleep.