Does hemineglect affect visual mental imagery? Imagery deficits in representational and perceptual neglect.

To give new insight about the relationship between imagery processes and different types of hemispatial neglect, we assessed different mental imagery abilities in a sample of right- and left-brain-damaged patients. Furthermore, because of reports of a mental representation disorder for environments in patients affected by representational neglect we also tested their navigational imagery ability. We found that patients with no signs of perceptual or representational neglect performed flawlessly on our imagery tasks regardless of whether they had left- or right-sided lesions. By contrast, patients affected by neglect failed most of the tests; in particular, representational neglect patients failed one test of mental transformation and tests requiring the manipulation of cognitive maps. These results suggest there is a specific relationship between hemispatial neglect and deficits in visual mental imagery and demonstrate that the right hemisphere plays a specific role in visual mental imagery.