In this study, we examine the case of a patient (NM) who could comprehend and produce numerals despite impairment on comprehension tasks and a high degree of anemia for other categories of words. It will be claimed that NM suffered from an impairment to the semantic system affecting all categories except numerals and the series of days and months. The case of a patient presenting with the exact reverse dissociation has been described a few years ago by Cipolotti et al. (Brain 1991; 114: 619-37). We conclude that NM's pattern of performance provides evidence that numerals constitute a relevant and perhaps a distinct category at the semantic level.
Thioux, M., Pillon, A., Samson, D., de Partz de Courtray, M.-P., Noël, M.-P., & Seron, X. (1998). The isolation of numerals at the semantic level. Neurocase, 4(4-5), 371-389. https://doi.org/10.1080/13554799808410633 (Original work published 1998)