each made up of four stages. (2)The four stagesconsist of one stage of rapid eye-movement sleep, or REM, and three of non rapid eye-movement sleep, known as N1, N2, and N3. Each cycle of four stages takes approximately 70 to 100 minutes to complete. ...
Sleep spindles appear during ___ sleep. A. REM B. N1 (R&K Stage 1) C. N2 (R&K Stage 2) D. N3 (R&K Stages 3 & 4) Stages of Sleep: Currently, four stages of sleep are recognized. The first three stages are called non-rapid eye...
N1 sleep duration (min) 70.5 (49.8–129.0) 53.5 (38.8–75.5) 0.019 0.006 1.019 1.007–1.031 0.002a N2 sleep duration (min) 237.0 (188.5–328.3) 232.8 (186.5–277.6) 0.001 0.003 1.001 0.996–1.007 0.719 N3 sleep duration (min) 16.5 (0.3–60.0) 27.5 (1.1–56.8) −0.003 0.006 0.997 0.9...