The variability of country map knowledge in normal and aphasic subjects: evidence from two new category-specific...

Two new category-specific screening tests are described, tapping naming to confrontation and word comprehension at two different levels of frequency. Level I consists of 10 very high-frequency items from each of the categories of animals, manmade artefacts, colours, body parts and countries. Level II probes knowledge of 10 marginally lower frequency items from the categories of animals, man-made artefacts, fruits and vegetables, body parts and countries. A standardization study of 120 healthy older adult subjects is reported. Performance at both levels of frequency in all categories except for countries was at or close to ceiling. A retrospective validation study in the form of a review of 20 cases published during the last 20 years demonstrates the utility of the Level I test for screening for category-specific deficits in severely aphasic patients who were not able to complete more demanding formal tests of naming and comprehension. The surprising variability of map knowledge observed in the standardization sample is considered in the light of one previous report and one newly presented case (IRQ) of apparent selective impairment of country map naming skills.