An advanced feature of the Sleep and Dream Database is the ability to analyze dream content using sleep stage measurements from the Zeo Sleep Manager as search constraints. So far, the SDDb has only one series with both dream reports and Zeo sleep data from the same nights (KB DJ 2009-2010). In coming months I will be pursuing new studies with other participants using a combination of dream journaling and the Zeo device. (If you’re interested in contributing to this research, please let me know!)
Using the word search template of the SDDb, I analyzed 135 dream reports with Zeo data in terms of total REM sleep, total light sleep, total deep sleep, total time awake during the night, and total ZQ (an aggregate number measuring overall sleep quality). For each of these five Zeo variables I divided the 135 reports into three or four subgroups of roughly equal number and average word length, then searched each subgroup to determine its frequency of using the seven word classes and forty word categories available in the SDDb.
At this very early stage of working with dream and Zeo data, my goal is to learn enough to be able to ask more refined questions in future research. The small size of these subgroups (28 the smallest, 52 the largest) means that the statistics are not definitive and surely include a fair amount of noise. The variation in average word length of the reports in each subset (105.53 the shortest, 142.49 the longest) is another reason to view these results cautiously. Some of the reports provide only a brief mention of sexual activity, omitting additional details for privacy reasons. The KB DJ 2009-2010 series has 182 total dreams, but 47 of the reports do not have corresponding Zeo data.
If patterns in the sleep data do correlate with patterns in dream content, I suspect the effects are likely to appear at the extremes, at the high and low ends of each measurement scale. Unusual frequencies may be nothing more than random noise, but they may also be genuine signals of interaction between sleep physiology and dream content. I’m hoping to identify where these signals might be appearing in data.
The spreadsheet with all the results can be found on Google docs.
Over the next few weeks I’ll post some comments about these data and what I think they mean. For anyone who repeats the SDDb word searches I did on the KB DJ 2009-2010 series and finds an error in my spreadsheet, I’ll send you a free book!