Loss of visual imagery: A generation deficit

The case of a patient with an impairment in the ability both to generate visual images and to perform certain transformations upon visual images is reported. No impairment of long-term visual memory could be demonstrated, and the patient was able to perform various tasks on a perceptually derived image indicating that the visual buffer is probably intact. Either the patient has two distinct impairments: a generation deficit and a transformation deficit, or these two problems are related and reflect an impairment of some form of imaged representation which is the repository both for images generated from long-term visual memory and for the images generated as a result of a mental rotation on a perceptually given stimulus item. The imaged representation must be presumed to be distinct from the visual buffer. The case is also of interest since the patient (with a left hemisphere lesion) was impaired in mental rotations, a deficit typically associated with right hemisphere lesions. © 1990, Taylor & Francis Group, LLC. All rights reserved.