section_path: Generation
section_name: Generation
paragraph_text: Generation
  
  Denied precision tools and obliged to depend on imaging, much dream research has succumbed to the law of the instrument. Studies detect an increase of blood flow in a specific brain region and then credit that region with a role in generating dreams. But pooling study results has led to the newer conclusion that dreaming involves large numbers of regions and pathways, which likely are different for different dream events.
  
  Image creation in the brain involves significant neural activity downstream from eye intake, and it is theorized that "the visual imagery of dreams is produced by activation during sleep of the same structures that generate complex visual imagery in waking perception."
  
  Dreams present a running narrative rather than exclusively visual imagery. Following their work with split-brain subjects, Gazzaniga and LeDoux postulated, without attempting to specify the neural mechanisms, a " left-brain interpreter " that seeks to create a plausible narrative from whatever electro-chemical signals reach the brain's left hemisphere. Sleep research has determined that some brain regions fully active during waking are, during REM sleep, activated only in a partial or fragmentary way. Drawing on this knowledge, textbook author James W. Kalat explains, " dream represents the brain's effort to make sense of sparse and distorted information.... The cortex combines this haphazard input with whatever other activity was already occurring and does its best to synthesize a story that makes sense of the information." Neuroscientist Indre Viskontas is even more blunt, calling often bizarre dream content "just the result of your interpreter trying to create a story out of random neural signaling."