We investigated the influence of semantically relevant information on comprehension deficit in 35 aphasic patients and 10 healthy controls. We developed new auditory word-picture matching tasks which were controlled by semantically relevant information between the target word and distracters, and evaluated the subjects in performing these tasks. The semantic relevance of the distracters consisted of "situational" relevance and "category" relevance with the target word. For example, the target word "dog" included situational (home) and category (mammal) information. For each task, six pictures (one target and five distracters) were presented to the subjects. One of the distracters had both situational and category associations with the target word (e.g., cat) , two others had either a situational or category association with the target word (e.g., home or elephant) , and the others had no relevance with the target word (e.g., eraser, etc) .
  The number of correct responses in the aphasic group was significantly lower than that in the control group. The mild aphasic subgroup showed errors mostly related to the target word, and there were few errors involving "non-relevant" items. The severe aphasic sub group showed more non-related errors than the mild aphasic sub group.
  These results suggest that situation and category are semantically relevant information that influence auditory word-comprehension deficit in aphasics.