Agnosia without prosopagnosia or alexia: Evidence for stored visual memories specific to objects

A single-case study is presented of a patient with a modality-specific problem in visual object recognition, which can be linked to impaired stored descriptions for objects. Performance was poor on tasks requiring naming, semantic decisions, and object decisions to seen objects. Performance on semantic decisions with words, however, was relatively good, demonstrating that the problem was not due solely to a general semantic impairment. Moreover, in contrast to the impairments in visual object recognition, both face recognition and on-line visual word recognition were within normal limits. The data indicate that impairments of object recognition can be distinguished from impairments of face and visual word recognition, even when the problem can be localised within the structural description system for objects. We discuss the implications of the results for understanding the relations between object, face, and word identification