Mental representation of space: insights from an oblique distribution of hallucinations.
Neuropsychologia March 25, 2007 Todd A. Girard, Désirée L M A Martius, J Allan Cheyne
Hallucinations experienced during sleep paralysis—both sensory and motor—tend to be projected toward the lower-left and especially the upper-right region of external space, a pattern that exceeds what would be expected from simply adding separate left-right and up-down biases. This oblique bias suggests a systematic link between hemispheric brain organization and ventral/dorsal cerebral pathways, adding to evidence that spatial preferences are multidimensional and not merely additive. The findings come from analyzing the three-dimensional distribution of hypnagogic and hypnopompic hallucinations, offering a window into internal spatial representation free from typical task-related influences.