AP Psychology Practice Test 2026 – 400 Free Practice Questions to Pass the Exam

The stage of sleep that is most notably associated with bursts of rapid, rhythmic brainwave activity is REM sleep. During this stage, the brain exhibits brainwaves similar to those when a person is awake, characterized by a highly active, dreaming state. This rapid eye movement phase is crucial for various cognitive functions, including memory consolidation and emotional processing. While stage 2 sleep contains some sleep spindles—short bursts of brain activity—it is not as pronounced as the brain activity found in REM sleep. Similarly, deep sleep involves slower brainwaves and is more restorative than active. The stage of falling asleep does not consistently display rhythmic brainwave patterns, as it is more of a transitional period. Thus, REM sleep is the stage where rapid, rhythmic brain activity is most prevalent, reflecting high brain activity associated with vivid dreaming.