The purpose of this experiment was to examine varying types of dreams and how they were connected with our everyday lives. Previous research has shown that the biological causes of dreams can be based on what type of sleep they are in, either REM or NREM, the amount of cortical activation caused by what point of the circadian cycle the dreamer is in, and the type of external or internal stimuli that may initiate the memory sources. In our first (correlational) study, we tested the strength of these relationships by examining naturalistic daily changes in their variables longitudinally over a two-week period. REM sleep was measured by using the information provided from the phone app called Pillow, giving us the percentage spent in REM, as well as the total minutes slept per night from each participant. Amount of sleep in the late circadian morning was measured by recording how many hours past midnight each participant slept in for each night of the study. The amount of light was measured with both the use of an app called Light Meter upon waking each morning and the number of words used to describe each recorded dream by their relevance to light stimulation. Dream recall was determined by the average score that participants gave themselves on a scale of 0-10, depending on the clarity of recalled dreams. Data pooled across participants in our correlational study showed no significant correlations of REM sleep or sleep in the late circadian morning with dream recall. Similarly, light stimulation showed no significant correlation with dream tallies. Although our correlations were not significant, the strongest was sleep in the late circadian morning and dream recall. Based on the strength of correlation found between the strength of dream recall and sleep in late circadian morning in our correlational study, we then conducted a second (experimental) study to test for specifically a causal relationship between these two variables. Over a ten-day period, we randomly assigned participants each day to wake up either one hour earlier or at their normal wake time and measured the effect this had upon dream recall each day. The results of our experimental study showed statistical significance in pooled raw data but not in pooled standardized data. The biological causes of dreams thus remain unsolved.
