Figure 1.

Histograms showing the distribution of sleep paralysis frequency, sleep paralysis intensity, and lucid dreaming frequency in the current sample. For sleep paralysis frequency, 0: never; 1: once; 2: several times in life; 3: several times a year; 4: monthly; 5: weekly; 6: several times a week. For sleep paralysis intensity, 0: not applicable, 1 (vague and suggestive, a hint of something) to 7 (a very clear and distinct impression, as clear as everyday experience). For lucid dreaming frequency, 0: never, 1: less than once a month, 2: about once a month, 3: twice or three times a month, 4: about once a week, 5: several times a week, 6: almost every morning.