◆ SpookStack

256 {126] LaBERGE/LEVITAN/DEMENT PHYSIOLOGY OF LUCID DREAMING 257 [127] Approved For Release 2000/08/08 : CIA-RDP96-00789R003100140001-2 10 08 O6 04 -0.2 -0.4 “50 -40 -30 -20 -10 00 10 20 309 40 50 RESPIRATION RATE of lucid dreams within REM periods. Having found that lucid dreams reliably occur during activated REM, we predicted that LDPROB would share significant variance with measures of CNS activation. Since it has been reported that eye-movement density starts at a low level at the beginning of REM periods and increases until it reaches a peak after approximately five to seven minutes (Aserinsky, 1971), we hypothesized that LDPROB should follow a parallel development. Accor- dingly, we found that mean eye-movement density (EM) correlated positive- ly and significantly with LDPROB (r=.66, p<.01). In a regression of LDPROB on EM and REMLEN, both variables entered significantly, giving an adjusted multiple R=.98 (p<.005). “50 -40 -30 -20 -10 00 10 20 30 40 50 SKIN POTENTIAL 1.0 03 oo — : Le LT “5.00 -46 -30 -20 -10 00 10 20 360 40 30 Figure 3: Histograms of mean Z-scores for EM, RR, HR, and SP. Bins are 30 seconds in length with t=0 representing the signaled onset of lucidity. Ns vary with variable and bin, but all values are averaged across lucid dreams and subjects. (*p<.05) most exclusively” towards the end of the night (Garfield, 1975; Green, 1968; LaBerge, 1985a). Cohen (1979) has argued that the left hemisphere shows a gradual increase in dominance across the night. Since left-hemisphere abstract symbelic functions are *-ndoubtedly crucial for lucid dreaming, Cohen's GILD hypothesis led us to predict (LaBerge, 1985b) that the probability of dream lucidity should increase with time of night. For each subject a median split for total REM time was determined; 11 of the subjects had more lucid dreams in the later half of REM than in the earlier half (binomial test; p<.01). For the combined sample, relative lucidity probability was calculated for REM periods 1-6 of the night by dividing the total number of lucid dreams observed in a given REM period by the cor- responding total time in stage REM for the same REM period. A regression analysis clearly demonstrated that relative lucidity probability was a linear function of ordinal REM period number (r=.98, p<.0001). No measure of ac- tivation (EM, RR, HR, SP) even approached significance when entered into the regression equation. These results strongly support the conclusion that lucid dreams are more likely to occur in later REM periods than in earlier ones—provided, of course, that sleep is continued long enough. Our demonstration that lucid dreams are reliably associated with elevated levels of physiological activation, may raise a question: why is lucid dream- ing the exception rather than the rule? After all, physiological activation ade- quate for lucidity probably occurs every night during most REM periods; why then do we not become lucid more frequently? It appears plausible that we usually lack an appropriate pre-sleep, and thus, REM cognitive set (i-e., the intention to become conscious of our dreaming). Although the importance of physiological factors in the genesis of dream lucidity is clear, it seems equally clear that psychological factors are no less important. It is also worth noting that the ability of lucid dreamers to deliberately per- form dream actions in accordance with pre-sleep agreement makes possible an experimental paradigm allowing the methodical and precise determina- Approved For Release 2000/08/08 : CIA-RDP96-00789R003100140001-2