Sleep experiences, dissociation, imaginal experiences, and schizotypy: the role of context.

Watson (2001) reported moderate correlations between the Iowa Sleep Experience Survey (ISES) and self-report measures of dissociation and schizotypy. Subsequent investigations (Fassler, Knox, & Lynn, 2003; Watson, 2003) reported similar, although somewhat more modest, correlations between the ISES and measures of dissociation and schizotypy, as well as with measures of absorption and negative affect. The present study tested subjects in conditions in which the measures of sleep experiences were administered with other measures in either the same (N=86) or a different (N=87) test context. We determined that sleep experiences were associated with measures of dissociation, absorption, and schizotypy. We closely replicated Watson (2001) and found that the ISES correlations with other measures were not affected by the test context. We suggest that Watson's (2001) hypothesized common domain of unusual cognitive and perceptual experiences (e.g., sleep experiences) may be underpinned by common ties to imaginative experiences.