In another series of experiments, Stickgold and his colleagues demonstrated that learning experiences are replayed at sleep onset. The researchers trained volunteers to play the computer game Tetris and sent them home with tape recorders and sleep monitors. Stickgold is especially interested in the function of dreams. For much of this century, the fields of neuroscience and psychoanalysis have differed greatly in their theories on dreaming. Freud thought that dreams served the purpose of both disguising and discharging unconscious drives while neuroscientists believed that dreams were a result of chaotic neuronal activity.
New findings point to a theory consistent both with laboratory findings and psychoanalytic theory.
Stickgold reviews recent research on dreams and memory in the December 1998 Trends in Cognitive Neuroscience. Memory Fixing Dreams appear to be part of some functional process because they are accompanied by changes in brain chemistry and the activation of different regions of the brain. There appears to be an alternating flow of information between the two areas. Stickgold hypothesizes that the shifts in direction between the hippocampus and the neocortex are providing a mechanism for consolidating and integrating memories. Integration may be taking place during sleep.