Positions on the indicated primary-to-secondary consciousness axis are based on the logarithm of ratios of mean scores in lucid and non-lucid dreams. All factors have been identified as components of dream consciousness. Lucid dreams, which are thought to add elements of secondary consciousness, are characterized by increased ratings in reflective INSIGHT, CONTROL, and DISSOCIATION; and, to a lesser extent, by access to MEMORY, as well as NEGATIVE and POSITIVE EMOTIONS. THOUGHT and REALISM do not differentiate between lucid and non-lucid dreams. The graph is based on the laboratory scores shown in Fig. 4 of Voss et al.9 (LuCiD scale). For validation purposes, mean scores of the dream reports under sham condition in the current sample were compared to those of the original study on the basis of which these factors were constructed9. Scores of both studies compared well, suggesting reliable subjective ratings in the current study (INSIGHT: t = 0.91, p = 0.366; CONTROL: t = 0.46, p = 0.647; THOUGHT: t = 1.20, p = 0.231; REALISM: t = 1.08, p = 0.283; MEMORY: t = 1.59, p = 0.133; DISSOCIATION: t = 0.73, p = 0.470; NEGATIVE EMOTION: t = 1.49, p = 0.139; POSITIVE EMOTION: t = 0.39, p = 0.700, df = 106, all n.s.).