The impact of September 11 on dreaming.

This study focuses on a set of dreams related to the September 11, 2001 terrorist attacks and their aftermath, using content analysis and cognitive psychology to explore the interweaving of external public catastrophe and internal psychological processes. The study tests several recent claims in contemporary dream research, including the central image theory of Hartmann [Hartmann, E., & Basile, R. (2003). Dream imagery becomes more intense after 9/11/01. Dreaming, 13(2), 61-66; Hartmann, E., & Brezler, T. (2008). A systematic change in dreams after 9/11/01. Sleep, 31(2), 213-218], the media exposure factor postulated by Propper [Propper, R. E., Stickgold, R., Keeley, R., & Christman, S. D. (2007). Is television traumatic? Dreams, stress, and media exposure in the aftermath of September 11, 2001. Psychological Science, 18(4), 334-340], the continuity hypothesis of Domhoff [Domhoff, W. G. (1996). Finding meaning in dreams: A quantitative approach. New York: Plenum], the cognitive and metacognitive approach of Kahan [Kahan, T. L. (2001). Consciousness in dreaming: A metacognitive approach. In K. Bulkeley (Ed.), Dreams: A reader on the religious, cultural, and psychological dimensions of dreaming (pp. 333-360). New York: Palgrave], and the threat simulation theory of Revonsuo [Revonsuo, A. (2000). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23(6), 877-901]. Our findings suggest the terrorist attacks had a tangible impact on the content of many people's dreams, but did not fundamentally alter the cognitive processing features of their dreaming. The 9/11 attacks affected what they dreamed about, but not the way they dreamed.