behrmann and colleagues (1992) describe a patient c.k., who provided evidence challenging the view that visual imagery and visual perception rely on the same representational system. c.k. was a 33-year old man with visual object agnosia acquired after a vehicular accident. this deficit prevented him from being able to recognize objects and copy objects fluidly. surprisingly, his ability to draw accurate objects from memory indicated his visual imagery was intact and normal. furthermore, c.k. successfully performed other tasks requiring visual imagery for judgment of size, shape, color, and composition. these findings conflict with previous research as they suggest there is a partial dissociation between visual imagery and visual perception. c.k. exhibited a perceptual deficit that was not associated with a corresponding deficit in visual imagery, indicating that these two processes have systems for mental representations that may not be mediated entirely by the same neural substrates.