|| Checking for direct PDF access through Ovid
Sensed presence (PRES), the illusory, often fearful impression of someone being present, is the most frequent type of imagery accompanying isolated sleep paralysis (ISP). Because of numerous similarities between PRES and social anxiety, the authors hypothesized that individuals who reported having had PRES during ISP would have higher levels of social anxiety than would either subjects who reported ISP without PRES or controls with neither experience. Forty-five university students (16 ISP + PRES, 10 ISP, 19 controls) were administered validated questionnaires measuring social anxiety, depression, and specific phobias. A one-way analysis of variance revealed that ISP + PRES subjects had higher social anxiety than ISP subjects (p = .013). The effect size for this analysis was large (.598). However, an analysis of covariance controlling for depression and specific phobias revealed a smaller intergroup difference (effect size = .464), a finding apparently due to elevated depression scores among ISP + PRES subjects (p < .001) rather than to differences in severity of phobias (ns).