To elucidate the role of visual and nonvisual attribute knowledge on
visual object identification, we present data from three patients, each
with visual object identification impairments as a result of different
etiologies. Patients were shown novel computer-generated shapes paired
with different labels referencing known entities. On test trials they were
shown the novel shapes alone and had to identify them by generating the
label with which they were formerly paired. In all conditions the same
triad of computer-generated shapes were used. In one condition, the labels
(banjo, guitar, violin) referenced entities that were both visually
similar and similar in terms of their nonvisual attributes within
semantics. In separate conditions we used labels (e.g., spike, straw,
pencil or snorkel, cane, crowbar) that referenced entities that were
similar in terms of their visual attributes but were dissimilar in terms
of their nonvisual attributes. The results revealed that nonvisual
attribute information profoundly influenced visual object identification.
Our patients performed significantly better when attempting to identify
shape triads whose labels referenced objects with distinct nonvisual
attributes versus shape triads whose labels referenced objects
with similar nonvisual attributes. We conclude that the nonvisual aspects
of meaning must be taken into consideration when assessing visual object
identification impairments. (JINS, 2006, 12,
176–183.)