Sleep spindles are characterized by which frequency range?

Sleep spindles are characterized by which frequency range?

• A. 8-12 Hz
• B. 15-18 Hz
• C. 12-14 Hz
• D. 4-8 Hz

Answer: (C)

Sleep spindles are brief bursts of rhythmic brain activity in the sigma range, classically around 12 to 14 Hz. They occur mainly during non-REM stage 2 sleep and arise from thalamocortical circuits, helping to stabilize sleep and support memory processing. Among the options, 12–14 Hz best matches the spindle range; frequencies like 8–12 Hz relate more to theta/low sigma and aren’t considered spindles, 15–18 Hz lies above the typical spindle range, and 4–8 Hz is delta activity seen in deep sleep. So the 12–14 Hz range is the correct characterization.

Sleep spindles are brief bursts of rhythmic brain activity in the sigma range, classically around 12 to 14 Hz. They occur mainly during non-REM stage 2 sleep and arise from thalamocortical circuits, helping to stabilize sleep and support memory processing. Among the options, 12–14 Hz best matches the spindle range; frequencies like 8–12 Hz relate more to theta/low sigma and aren’t considered spindles, 15–18 Hz lies above the typical spindle range, and 4–8 Hz is delta activity seen in deep sleep. So the 12–14 Hz range is the correct characterization.